From f20f5c629da646dd6a064d2516d68dba11fdba0c Mon Sep 17 00:00:00 2001
From: Bob Supnik <bob@supnik.org>
Date: Fri, 7 Feb 2003 21:28:00 -0800
Subject: [PATCH] Notes For V2.10-3

1. New Features in 2.10-3

1.1 SCP and Libraries

- Added dynamic extension of the breakpoint table.
- Added breakpoint actions.
- Added VMS support for ! (from Mark Pizzolato).

1.2 18b PDP's

- Added RB09 fixed head disk for the PDP-9.
- Added LP09 line printer for the PDP-9 and PDP-15.
- Added variable size support and autosizing to the RF15/RF09.

1.3 PDP-8

- Added variable size support and autosizing to the DF32 and RF08.

1.4 Nova

- Added variable size support and autosizing to the Novadisk.

2. Bugs Fixed in 2.10-3

- 18b PDP RF15/RF09: fixed IOT decoding and address wraparound
  logic (found by Hans Pufal).
- 18b PDP RP15: fixed IOT decoding and command initiation.
- HP2100 IPL: changed to full duplex (found by Mike Gemeny).
- HP2100 CPU: fixed last cycle bug in DMA outpout (found by Mike
  Gemeny).
- Interdata 16b CPU: fixed bug in SETM, SETMR (found by Mark
  Pizzolato).

3. New Features in 2.10 vs prior releases

3.1 SCP and Libraries

- The VT emulation package has been replaced by the capability
  to remote the console to a Telnet session.  Telnet clients
  typically have more complete and robust VT100 emulation.
- Simulated devices may now have statically allocated buffers,
  in addition to dynamically allocated buffers or disk-based
  data stores.
- The DO command now takes substitutable arguments (max 9).
  In command files, %n represents substitutable argument n.
- The initial command line is now interpreted as the command
  name and substitutable arguments for a DO command.  This is
  backward compatible to prior versions.
- The initial command line parses switches.  -Q is interpreted
  as quiet mode; informational messages are suppressed.
- The HELP command now takes an optional argument.  HELP <cmd>
  types help on the specified command.
- Hooks have been added for implementing GUI-based consoles,
  as well as simulator-specific command extensions.  A few
  internal data structures and definitions have changed.
- Two new routines (tmxr_open_master, tmxr_close_master) have
  been added to sim_tmxr.c.  The calling sequence for
  sim_accept_conn has been changed in sim_sock.c.
- The calling sequence for the VM boot routine has been modified
  to add an additional parameter.
- SAVE now saves, and GET now restores, controller and unit flags.
- Library sim_ether.c has been added for Ethernet support.
- The EVAL command will evaluate a symbolic type-in and display
  it in numeric form.
- The ! command (with no arguments) will launch the host operating
  system command shell.  The ! command (with an argument) executes
  the argument as a host operating system command.  (Code from
  Mark Pizzolato)
- Telnet sessions now recognize BREAK.  How a BREAK is transmitted
  dependent on the particular Telnet client.  (Code from Mark
  Pizzolato)
- The sockets library includes code for active connections as
  well as listening connections.
- The RESTORE command will restore saved memory size, if the
  simulator supports dynamic memory resizing.

3.2 VAX

- Non-volatile RAM (NVR) can behave either like a memory or like
  a disk-based peripheral.  If unattached, it behaves like memory
  and is saved and restored by SAVE and RESTORE, respectively.
  If attached, its contents are loaded from disk by ATTACH and
  written back to disk at DETACH and EXIT.
- SHOW <device> VECTOR displays the device's interrupt vector.
  A few devices allow the vector to be changed with SET
  <device> VECTOR=nnn.
- SHOW CPU IOSPACE displays the I/O space address map.
- The TK50 (TMSCP tape) has been added.
- The DEQNA/DELQA (Qbus Ethernet controllers) have been added.
- Autoconfiguration support has been added.
- The paper tape reader has been removed from vax_stddev.c and
  now references a common implementation file, dec_pt.h.
- Examine and deposit switches now work on all devices, not just
  the CPU.
- Device address conflicts are not detected until simulation starts.
- If the VAX console is attached to a Telnet session, BREAK is
  interpreted as console halt.
- The SET/SHOW HISTORY commands enable and display a history of
  the most recently executed instructions.  (Code from Mark
  Pizzolato)

3.3 PDP-11

- SHOW <device> VECTOR displays the device's interrupt vector.
  Most devices allow the vector to be changed with SET
  <device> VECTOR=nnn.
- SHOW CPU IOSPACE displays the I/O space address map.
- The TK50 (TMSCP tape), RK611/RK06/RK07 (cartridge disk),
  RX211 (double density floppy), and KW11P programmable clock
  have been added.
- The DEQNA/DELQA (Qbus Ethernet controllers) have been added.
- Autoconfiguration support has been added.
- The paper tape reader has been removed from pdp11_stddev.c and
  now references a common implementation file, dec_pt.h.
- Device bootstraps now use the actual CSR specified by the
  SET ADDRESS command, rather than just the default CSR.  Note
  that PDP-11 operating systems may NOT support booting with
  non-standard addresses.
- Specifying more than 256KB of memory, or changing the bus
  configuration, causes all peripherals that are not compatible
  with the current bus configuration to be disabled.
- Device address conflicts are not detected until simulation starts.
- The PDP-11 implements a stub DEUNA/DELUA (XU).  The real XU
  module will be included in a later release.

3.4 PDP-10

- SHOW <device> VECTOR displays the device's interrupt vector.
  A few devices allow the vector to be changed with SET
  <device> VECTOR=nnn.
- SHOW CPU IOSPACE displays the I/O space address map.
- The RX211 (double density floppy) has been added; it is off
  by default.
- The paper tape now references a common implementation file,
  dec_pt.h.
- Device address conflicts are not detected until simulation starts.
- The PDP-10 implements a stub DEUNA/DELUA (XU).  The real XU
  module will be included in a later release.

3.5 PDP-1

- DECtape (then known as MicroTape) support has been added.
- The line printer and DECtape can be disabled and enabled.
- The PDP-1 supports the Type 24 serial drum (based on recently
  discovered documents).

3.6 18b PDP's

- The PDP-4 supports the Type 24 serial drum (based on recently
  discovered documents).

3.7 PDP-8

- The RX28 (double density floppy) has been added as an option to
  the existing RX8E controller.
- SHOW <device> DEVNO displays the device's device number.  Most
  devices allow the device number to be changed with SET <device>
  DEVNO=nnn.
- Device number conflicts are not detected until simulation starts.

3.8 AltairZ80

- A hard drive has been added for increased storage.
- Several bugs have been fixed.

3.9 HP 2100

- The 12845A has been added and made the default line printer (LPT).
  The 12653A has been renamed LPS and is off by default.  It also
  supports the diagnostic functions needed to run the DCPC and DMS
  diagnostics.
- The 12557A/13210A disk defaults to the 13210A (7900/7901).
- The 12559A magtape is off by default.
- New CPU options (EAU/NOEAU) enable/disable the extended arithmetic
  instructions for the 2116.  These instructions are standard on
  the 2100 and 21MX.
- New CPU options (MPR/NOMPR) enable/disable memory protect for the
  2100 and 21MX.
- New CPU options (DMS/NODMS) enable/disable the dynamic mapping
  instructions for the 21MX.
- The 12539 timebase generator autocalibrates.
- The IOP microinstruction set is supported for the 21MX as well
  as the 2100.
- The HP2100 supports the Access Interprocessor Link (IPL).

3.10 Simulated Magtapes

- Simulated magtapes recognize end of file and the marker
  0xFFFFFFFF as end of medium.  Only the TMSCP tape simulator
  can generate an end of medium marker.
- The error handling in simulated magtapes was overhauled to be
  consistent through all simulators.

3.11 Simulated DECtapes

- Added support for RT11 image file format (256 x 16b) to DECtapes.

3.12 Terminals Multiplexors

- BREAK detection was added to the HP, DEC, and Interdata terminal
  multiplexors.

4. Bugs Fixed in 2.10 vs prior releases

- TS11/TSV05 was not simulating the XS0_MOT bit, causing failures
  under VMS.  In addition, two of the CTL options were coded
  interchanged.
- IBM 1401 tape was not setting a word mark under group mark for
  load mode reads.  This caused the diagnostics to crash.
- SCP bugs in ssh_break and set_logon were fixed (found by Dave
  Hittner).
- Numerous bugs in the HP 2100 extended arithmetic, floating point,
  21MX, DMS, and IOP instructions were fixed.  Bugs were also fixed
  in the memory protect and DMS functions.  The moving head disks
  (DP, DQ) were revised to simulate the hardware more accurately.
  Missing functions in DQ (address skip, read address) were added.
- PDP-10 tape wouldn't boot, and then wouldn't read (reported by
  Michael Thompson and Harris Newman, respectively)
- PDP-1 typewriter is half duplex, with only one shift state for
  both input and output (found by Derek Peschel)
- PDP-11 console must default to 7b for early UNIX compatibility.
- PDP-11/VAX TMSCP emulator was using the wrong packet length for
  read/write end packets.
- Telnet IAC+IAC processing was fixed, both for input and output
  (found by Mark Pizzolato).
- PDP-11/VAX Ethernet setting flag bits wrong for chained
  descriptors (found by Mark Pizzolato).

5. General Notes

WARNING: The build procedures have changed.  There is only one UNIX
makefile.  To compile without Ethernet support, simply type

	gmake {target|all}

To compile with Ethernet support, type

	gmake USE_NETWORK=1 {target|all}

The Mingw batch files require Mingw release 2 and invoke the Unix
makefile.  There are still separate batch files for compilation
with or without Ethernet support.

WARNING: V2.10 has reorganized and renamed some of the definition
files for the PDP-10, PDP-11, and VAX.  Be sure to delete all
previous source files before you unpack the Zip archive, or
unpack it into a new directory structure.

WARNING: V2.10 has a new, more comprehensive save file format.
Restoring save files from previous releases will cause 'invalid
register' errors and loss of CPU option flags, device enable/
disable flags, unit online/offline flags, and unit writelock
flags.

WARNING: If you are using Visual Studio .NET through the IDE,
be sure to turn off the /Wp64 flag in the project settings, or
dozens of spurious errors will be generated.

WARNING: Compiling Ethernet support under Windows requires
extra steps; see the Ethernet readme file.  Ethernet support is
currently available only for Windows, Linux, NetBSD, and OpenBSD.
---
 0readme_210.txt        | 162 ++++----
 HP2100/hp2100_cpu.c    |  31 +-
 HP2100/hp2100_doc.txt  |   2 +-
 HP2100/hp2100_ipl.c    |  56 +--
 Interdata/id16_cpu.c   |   4 +-
 Interdata/id32_cpu.c   |   2 +
 NOVA/nova_cpu.c        |  17 +-
 NOVA/nova_defs.h       |   5 +-
 NOVA/nova_doc.txt      |  22 +-
 NOVA/nova_dsk.c        |  64 ++-
 PDP10/pdp10_rp.c       |   4 +-
 PDP10/pdp10_tu.c       |  15 +-
 PDP11/pdp11_cpu.c      |  88 +++--
 PDP11/pdp11_defs.h     |  11 +-
 PDP11/pdp11_doc.txt    |   8 +-
 PDP11/pdp11_fp.c       |   7 +-
 PDP11/pdp11_rp.c       |   4 +-
 PDP18B/pdp18b_cpu.c    |   2 +-
 PDP18B/pdp18b_defs.h   |  25 +-
 PDP18B/pdp18b_doc.txt  | 104 ++++-
 PDP18B/pdp18b_lp.c     | 877 +++++++++++++++++++++++++----------------
 PDP18B/pdp18b_mt.c     |  68 ++--
 PDP18B/pdp18b_rb.c     | 273 +++++++++++++
 PDP18B/pdp18b_rf.c     | 166 +++++---
 PDP18B/pdp18b_rp.c     | 126 +++---
 PDP18B/pdp18b_stddev.c |   9 +-
 PDP18B/pdp18b_sys.c    |  72 +++-
 PDP8/pdp8_df.c         |  61 ++-
 PDP8/pdp8_doc.txt      |  34 +-
 PDP8/pdp8_rf.c         |  83 +++-
 descrip.mms            |  10 +-
 makefile               |   2 +-
 scp.c                  | 110 ++++--
 sim_rev.h              |  38 +-
 simh_doc.txt           |  19 +-
 simh_swre.txt          |  42 +-
 36 files changed, 1851 insertions(+), 772 deletions(-)
 create mode 100644 PDP18B/pdp18b_rb.c

diff --git a/0readme_210.txt b/0readme_210.txt
index 194a44b7..2dc98947 100644
--- a/0readme_210.txt
+++ b/0readme_210.txt
@@ -1,92 +1,37 @@
-Notes For V2.10-2
+Notes For V2.10-3
 
-1. New Features in 2.10-2
-
-The build procedures have changed.  There is only one UNIX makefile.
-To compile without Ethernet support, simply type
-
-	gmake {target|all}
-
-To compile with Ethernet support, type
-
-	gmake USE_NETWORK=1 {target|all}
-
-The Mingw batch files require Mingw release 2 and invoke the Unix
-makefile.  There are still separate batch files for compilation
-with or without Ethernet support.
+1. New Features in 2.10-3
 
 1.1 SCP and Libraries
 
-- The EVAL command will evaluate a symbolic type-in and display
-  it in numeric form.
-- The ! command (with no arguments) will launch the host operating
-  system command shell.  The ! command (with an argument) executes
-  the argument as a host operating system command.  (Code from
-  Mark Pizzolato)
-- Telnet sessions now recognize BREAK.  How a BREAK is transmitted
-  dependent on the particular Telnet client.  (Code from Mark
-  Pizzolato)
-- The sockets library includes code for active connections as
-  well as listening connections.
-- The RESTORE command will restore saved memory size, if the
-  simulator supports dynamic memory resizing.
+- Added dynamic extension of the breakpoint table.
+- Added breakpoint actions.
+- Added VMS support for ! (from Mark Pizzolato).
 
-1.2 PDP-1
+1.2 18b PDP's
 
-- The PDP-1 supports the Type 24 serial drum (based on recently
-  discovered documents).
+- Added RB09 fixed head disk for the PDP-9.
+- Added LP09 line printer for the PDP-9 and PDP-15.
+- Added variable size support and autosizing to the RF15/RF09.
 
-1.3 18b PDP's
+1.3 PDP-8
 
-- The PDP-4 supports the Type 24 serial drum (based on recently
-  discovered documents).
+- Added variable size support and autosizing to the DF32 and RF08.
 
-1.4 PDP-11
+1.4 Nova
 
-- The PDP-11 implements a stub DEUNA/DELUA (XU).  The real XU
-  module will be included in a later release.
+- Added variable size support and autosizing to the Novadisk.
 
-1.5 PDP-10
+2. Bugs Fixed in 2.10-3
 
-- The PDP-10 implements a stub DEUNA/DELUA (XU).  The real XU
-  module will be included in a later release.
-
-1.6 HP 2100
-
-- The IOP microinstruction set is supported for the 21MX as well
-  as the 2100.
-- The HP2100 supports the Access Interprocessor Link (IPL).
-
-1.7 VAX
-
-- If the VAX console is attached to a Telnet session, BREAK is
-  interpreted as console halt.
-- The SET/SHOW HISTORY commands enable and display a history of
-  the most recently executed instructions.  (Code from Mark
-  Pizzolato)
-
-1.8 Terminals Multiplexors
-
-- BREAK detection was added to the HP, DEC, and Interdata terminal
-  multiplexors.
-
-1.9 Interdata 16b and 32b
-
-- First release.  UNIX is not yet working.
-
-1.10 SDS 940
-
-- First release.
-
-2. Bugs Fixed in 2.10-2
-
-- PDP-11 console must default to 7b for early UNIX compatibility.
-- PDP-11/VAX TMSCP emulator was using the wrong packet length for
-  read/write end packets.
-- Telnet IAC+IAC processing was fixed, both for input and output
-  (found by Mark Pizzolato).
-- PDP-11/VAX Ethernet setting flag bits wrong for chained
-  descriptors (found by Mark Pizzolato).
+- 18b PDP RF15/RF09: fixed IOT decoding and address wraparound
+  logic (found by Hans Pufal).
+- 18b PDP RP15: fixed IOT decoding and command initiation.
+- HP2100 IPL: changed to full duplex (found by Mike Gemeny).
+- HP2100 CPU: fixed last cycle bug in DMA outpout (found by Mike
+  Gemeny).
+- Interdata 16b CPU: fixed bug in SETM, SETMR (found by Mark
+  Pizzolato).
 
 3. New Features in 2.10 vs prior releases
 
@@ -117,6 +62,19 @@ with or without Ethernet support.
   to add an additional parameter.
 - SAVE now saves, and GET now restores, controller and unit flags.
 - Library sim_ether.c has been added for Ethernet support.
+- The EVAL command will evaluate a symbolic type-in and display
+  it in numeric form.
+- The ! command (with no arguments) will launch the host operating
+  system command shell.  The ! command (with an argument) executes
+  the argument as a host operating system command.  (Code from
+  Mark Pizzolato)
+- Telnet sessions now recognize BREAK.  How a BREAK is transmitted
+  dependent on the particular Telnet client.  (Code from Mark
+  Pizzolato)
+- The sockets library includes code for active connections as
+  well as listening connections.
+- The RESTORE command will restore saved memory size, if the
+  simulator supports dynamic memory resizing.
 
 3.2 VAX
 
@@ -137,6 +95,11 @@ with or without Ethernet support.
 - Examine and deposit switches now work on all devices, not just
   the CPU.
 - Device address conflicts are not detected until simulation starts.
+- If the VAX console is attached to a Telnet session, BREAK is
+  interpreted as console halt.
+- The SET/SHOW HISTORY commands enable and display a history of
+  the most recently executed instructions.  (Code from Mark
+  Pizzolato)
 
 3.3 PDP-11
 
@@ -159,6 +122,8 @@ with or without Ethernet support.
   configuration, causes all peripherals that are not compatible
   with the current bus configuration to be disabled.
 - Device address conflicts are not detected until simulation starts.
+- The PDP-11 implements a stub DEUNA/DELUA (XU).  The real XU
+  module will be included in a later release.
 
 3.4 PDP-10
 
@@ -171,13 +136,22 @@ with or without Ethernet support.
 - The paper tape now references a common implementation file,
   dec_pt.h.
 - Device address conflicts are not detected until simulation starts.
+- The PDP-10 implements a stub DEUNA/DELUA (XU).  The real XU
+  module will be included in a later release.
 
 3.5 PDP-1
 
 - DECtape (then known as MicroTape) support has been added.
 - The line printer and DECtape can be disabled and enabled.
+- The PDP-1 supports the Type 24 serial drum (based on recently
+  discovered documents).
 
-3.6 PDP-8
+3.6 18b PDP's
+
+- The PDP-4 supports the Type 24 serial drum (based on recently
+  discovered documents).
+
+3.7 PDP-8
 
 - The RX28 (double density floppy) has been added as an option to
   the existing RX8E controller.
@@ -186,10 +160,6 @@ with or without Ethernet support.
   DEVNO=nnn.
 - Device number conflicts are not detected until simulation starts.
 
-3.7 IBM 1620
-
-- The IBM 1620 simulator has been released.
-
 3.8 AltairZ80
 
 - A hard drive has been added for increased storage.
@@ -211,6 +181,9 @@ with or without Ethernet support.
 - New CPU options (DMS/NODMS) enable/disable the dynamic mapping
   instructions for the 21MX.
 - The 12539 timebase generator autocalibrates.
+- The IOP microinstruction set is supported for the 21MX as well
+  as the 2100.
+- The HP2100 supports the Access Interprocessor Link (IPL).
 
 3.10 Simulated Magtapes
 
@@ -224,6 +197,11 @@ with or without Ethernet support.
 
 - Added support for RT11 image file format (256 x 16b) to DECtapes.
 
+3.12 Terminals Multiplexors
+
+- BREAK detection was added to the HP, DEC, and Interdata terminal
+  multiplexors.
+
 4. Bugs Fixed in 2.10 vs prior releases
 
 - TS11/TSV05 was not simulating the XS0_MOT bit, causing failures
@@ -242,9 +220,29 @@ with or without Ethernet support.
   Michael Thompson and Harris Newman, respectively)
 - PDP-1 typewriter is half duplex, with only one shift state for
   both input and output (found by Derek Peschel)
+- PDP-11 console must default to 7b for early UNIX compatibility.
+- PDP-11/VAX TMSCP emulator was using the wrong packet length for
+  read/write end packets.
+- Telnet IAC+IAC processing was fixed, both for input and output
+  (found by Mark Pizzolato).
+- PDP-11/VAX Ethernet setting flag bits wrong for chained
+  descriptors (found by Mark Pizzolato).
 
 5. General Notes
 
+WARNING: The build procedures have changed.  There is only one UNIX
+makefile.  To compile without Ethernet support, simply type
+
+	gmake {target|all}
+
+To compile with Ethernet support, type
+
+	gmake USE_NETWORK=1 {target|all}
+
+The Mingw batch files require Mingw release 2 and invoke the Unix
+makefile.  There are still separate batch files for compilation
+with or without Ethernet support.
+
 WARNING: V2.10 has reorganized and renamed some of the definition
 files for the PDP-10, PDP-11, and VAX.  Be sure to delete all
 previous source files before you unpack the Zip archive, or
diff --git a/HP2100/hp2100_cpu.c b/HP2100/hp2100_cpu.c
index 68e4ebdc..ea33b049 100644
--- a/HP2100/hp2100_cpu.c
+++ b/HP2100/hp2100_cpu.c
@@ -1,6 +1,6 @@
 /* hp2100_cpu.c: HP 2100 CPU simulator
 
-   Copyright (c) 1993-2002, Robert M. Supnik
+   Copyright (c) 1993-2003, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   02-Feb-03	RMS	Fixed last cycle bug in DMA output (found by Mike Gemeny)
    22-Nov-02	RMS	Added 21MX IOP support
    24-Oct-02	RMS	Fixed bugs in IOP and extended instructions
 			Fixed bugs in memory protection and DMS
@@ -2349,7 +2350,17 @@ if (IR & I_HC) { clrFLG (DMA0 + ch); }			/* HC option */
 return dat;
 }
 
-/* DMA cycle routine */
+/* DMA cycle routine
+
+   The last cycle (word count reaches 0) logic is quite tricky.
+   Input cases:
+   - CLC requested: issue CLC
+   Output cases:
+   - neither STC nor CLC requested: issue CLF
+   - CLC requested but not STC: issue CLC,C
+   - STC requested but not CLC: issue STC,C
+   - STC and CLC both requested: issue STC,C and CLC,C
+*/
 
 void dma_cycle (uint32 ch, uint32 map)
 {
@@ -2369,11 +2380,17 @@ if (dmac[ch].cw3) {					/* more to do? */
 	if (dmac[ch].cw1 & DMA1_STC)			/* if STC flag, */
 	    devdisp (dev, ioCTL, I_HC + dev, 0);	/* do STC,C dev */
 	else devdisp (dev, ioFLG, I_HC + dev, 0);  }	/* else CLF dev */
-else {	if (!inp) devdisp (dev, ioFLG, I_HC + dev, 0);	/* output? clr flag */
-	if (dmac[ch].cw1 & DMA1_CLC)			/* CLC at end? */
-	    devdisp (dev, ioCTL, I_CTL + dev, 0);	/* yes */
-	else if (!inp && (dmac[ch].cw1 & DMA1_STC))	/* STC && output? */
-	    devdisp (dev, ioCTL, I_HC + dev, 0);	/* STC,C */
+else {	if (inp) {					/* last cycle, input? */
+	    if (dmac[ch].cw1 & DMA1_CLC)		/* CLC at end? */
+		devdisp (dev, ioCTL, I_CTL + dev, 0);	/* yes */
+	    }						/* end input */
+	else {						/* output */
+	    devdisp (dev, ioFLG, I_HC + dev, 0);	/* clear flag */
+	    if (dmac[ch].cw1 & DMA1_STC)		/* if STC flag, */
+		devdisp (dev, ioCTL, dev, 0);		/* do STC dev */
+	    if (dmac[ch].cw1 & DMA1_CLC)		/* CLC at end? */
+	        devdisp (dev, ioCTL, I_CTL + dev, 0);	/* yes */
+	    }						/* end output */
 	setFLG (DMA0 + ch);				/* set DMA flg */
 	clrCMD (DMA0 + ch);  }				/* clr DMA cmd */
 return;
diff --git a/HP2100/hp2100_doc.txt b/HP2100/hp2100_doc.txt
index 58b77bb2..7f942089 100644
--- a/HP2100/hp2100_doc.txt
+++ b/HP2100/hp2100_doc.txt
@@ -75,7 +75,7 @@ PTR,PTP		12597A paper tape reader/punch
 TTY		12631C buffered terminal controller
 LPS		12653A printer controller with 2767 printer
 		12566B microcircuit interface for diagnostics
-LPT		12845A printer controller
+LPT		12845A printer controller with 2607 printer
 CLK		12539A/B/C time base generator
 MUXL,MUXU,MUXC	12920A terminal multiplexor
 DP		12557A disk controller with four 2871 drives
diff --git a/HP2100/hp2100_ipl.c b/HP2100/hp2100_ipl.c
index a1fbfa43..e5c95cb1 100644
--- a/HP2100/hp2100_ipl.c
+++ b/HP2100/hp2100_ipl.c
@@ -1,6 +1,6 @@
 /* hp2100_ipl.c: HP 2000 interprocessor link simulator
 
-   Copyright (c) 2002, Robert M Supnik
+   Copyright (c) 2002-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -24,6 +24,8 @@
    in this Software without prior written authorization from Robert M Supnik.
 
    ipli, iplo	12556B interprocessor link pair
+
+   31-Jan-03	RMS	Links are full duplex (found by Mike Gemeny)
 */
 
 #include "hp2100_defs.h"
@@ -33,19 +35,22 @@
 #define UNIT_V_DIAG	(UNIT_V_UF + 0)			/* diagnostic mode */
 #define UNIT_V_ACTV	(UNIT_V_UF + 1)			/* making connection */
 #define UNIT_V_ESTB	(UNIT_V_UF + 2)			/* connection established */
+#define UNIT_V_HOLD	(UNIT_V_UF + 3)			/* character holding */
 #define UNIT_DIAG	(1 << UNIT_V_DIAG)
 #define UNIT_ACTV	(1 << UNIT_V_ACTV)
 #define UNIT_ESTB	(1 << UNIT_V_ESTB)
+#define UNIT_HOLD	(1 << UNIT_V_HOLD)
+#define IBUF		buf				/* input buffer */
+#define OBUF		wait				/* output buffer */
 #define DSOCKET		u3				/* data socket */
 #define LSOCKET		u4				/* listening socket */
-#define HOLD		wait				/* holding byte */
-#define IPL_HOLD	0100000
 
 extern uint32 PC;
 extern uint32 dev_cmd[2], dev_ctl[2], dev_flg[2], dev_fbf[2];
 extern FILE *sim_log;
 int32 ipl_ptime = 400;					/* polling interval */
 int32 ipl_stopioe = 0;					/* stop on error */
+int32 ipl_hold[2] = { 0 };				/* holding character */
 
 DEVICE ipli_dev, iplo_dev;
 int32 ipliio (int32 inst, int32 IR, int32 dat);
@@ -82,12 +87,13 @@ UNIT ipl_unit[] = {
 #define iplo_unit ipl_unit[1]
 
 REG ipli_reg[] = {
-	{ ORDATA (BUF, ipli_unit.buf, 16) },
+	{ ORDATA (IBUF, ipli_unit.IBUF, 16) },
+	{ ORDATA (OBUF, ipli_unit.OBUF, 16) },
 	{ FLDATA (CMD, ipli_dib.cmd, 0) },
 	{ FLDATA (CTL, ipli_dib.ctl, 0) },
 	{ FLDATA (FLG, ipli_dib.flg, 0) },
 	{ FLDATA (FBF, ipli_dib.fbf, 0) },
-	{ ORDATA (HOLD, ipli_unit.HOLD, 16) },
+	{ ORDATA (HOLD, ipl_hold[0], 8) },
 	{ DRDATA (TIME, ipl_ptime, 24), PV_LEFT },
 	{ FLDATA (STOP_IOE, ipl_stopioe, 0) },
 	{ ORDATA (DEVNO, ipli_dib.devno, 6), REG_HRO },
@@ -117,12 +123,13 @@ DEVICE ipli_dev = {
 */
 
 REG iplo_reg[] = {
-	{ ORDATA (BUF, iplo_unit.buf, 16) },
+	{ ORDATA (IBUF, iplo_unit.IBUF, 16) },
+	{ ORDATA (OBUF, iplo_unit.OBUF, 16) },
 	{ FLDATA (CMD, iplo_dib.cmd, 0) },
 	{ FLDATA (CTL, iplo_dib.ctl, 0) },
 	{ FLDATA (FLG, iplo_dib.flg, 0) },
 	{ FLDATA (FBF, iplo_dib.fbf, 0) },
-	{ ORDATA (HOLD, iplo_unit.HOLD, 16) },
+	{ ORDATA (HOLD, ipl_hold[1], 8) },
 	{ DRDATA (TIME, ipl_ptime, 24), PV_LEFT },
 	{ ORDATA (DEVNO, iplo_dib.devno, 6), REG_HRO },
 	{ NULL }  };
@@ -164,13 +171,13 @@ case ioSFS:						/* skip flag set */
 	if (FLG (dev) != 0) PC = (PC + 1) & VAMASK;
 	return dat;
 case ioOTX:						/* output */
-	uptr->buf = dat;
+	uptr->OBUF = dat;
 	break;
 case ioLIX:						/* load */
-	dat = uptr->buf;				/* return val */
+	dat = uptr->IBUF;				/* return val */
 	break;
 case ioMIX:						/* merge */
-	dat = dat | uptr->buf;				/* get return data */
+	dat = dat | uptr->IBUF;				/* get return data */
 	break;
 case ioCTL:						/* control clear/set */
 	if (IR & I_CTL) {				/* CLC */
@@ -184,8 +191,8 @@ case ioCTL:						/* control clear/set */
 		    if (!ipl_check_conn (uptr))		/* not established? */
 			return STOP_NOCONN;		/* lose */
 		    uptr->flags = uptr->flags | UNIT_ESTB;  }
-		msg[0] = (uptr->buf >> 8) & 0377;
-		msg[1] = uptr->buf & 0377;
+		msg[0] = (uptr->OBUF >> 8) & 0377;
+		msg[1] = uptr->OBUF & 0377;
 		sta = sim_write_sock (uptr->DSOCKET, msg, 2);
 		if (sta == SOCKET_ERROR) {
 		    printf ("IPL: socket write error\n");
@@ -193,7 +200,7 @@ case ioCTL:						/* control clear/set */
 		sim_os_sleep (0);  }
 	    else if (uptr->flags & UNIT_DIAG) {		/* diagnostic mode? */
 		u = (uptr - ipl_unit) ^ 1;		/* find other device */
-		ipl_unit[u].buf = uptr->buf;		/* output to other */
+		ipl_unit[u].IBUF = uptr->OBUF;		/* output to other */
 		odev = ipl_dib[u].devno;		/* other device no */
 		setFLG (odev);  }			/* set other flag */
 	    else return SCPE_UNATT;  }			/* lose */
@@ -211,23 +218,25 @@ t_stat ipl_svc (UNIT *uptr)
 int32 u, nb, dev;
 int8 msg[2];
 
+u = uptr - ipl_unit;					/* get link number */
 if ((uptr->flags & UNIT_ATT) == 0) return SCPE_OK;	/* not attached? */
 sim_activate (uptr, ipl_ptime);				/* reactivate */
 if ((uptr->flags & UNIT_ESTB) == 0) {			/* not established? */
 	if (!ipl_check_conn (uptr)) return SCPE_OK;	/* check for conn */
 	uptr->flags = uptr->flags | UNIT_ESTB;  }
-nb = sim_read_sock (uptr->DSOCKET, msg, uptr->HOLD? 1: 2);
+nb = sim_read_sock (uptr->DSOCKET, msg, ((uptr->flags & UNIT_HOLD)? 1: 2));
 if (nb < 0) {						/* connection closed? */
 	printf ("IPL: socket read error\n");
 	return SCPE_IOERR;  }
 if (nb == 0) return SCPE_OK;				/* no data? */
-if (uptr->HOLD) {					/* holdover byte? */
-	uptr->buf = ((uptr->HOLD & 0377) << 8) | (((int32) msg[0]) & 0377);
-	uptr->HOLD = 0;  }
-else if (nb == 1) uptr->HOLD = (((int32) msg[0]) & 0377) | IPL_HOLD;
-else uptr->buf = ((((int32) msg[0]) & 0377) << 8) |
+if (uptr->flags & UNIT_HOLD) {				/* holdover byte? */
+	uptr->IBUF = (ipl_hold[u] << 8) | (((int32) msg[0]) & 0377);
+	uptr->flags = uptr->flags & ~UNIT_HOLD;  }
+else if (nb == 1) {
+	ipl_hold[u] = ((int32) msg[0]) & 0377;
+	uptr->flags = uptr->flags | UNIT_HOLD;  }
+else uptr->IBUF = ((((int32) msg[0]) & 0377) << 8) |
 	(((int32) msg[1]) & 0377);
-u = uptr - ipl_unit;					/* get link number */
 dev = ipl_dib[u].devno;					/* get device number */
 clrCMD (dev);						/* clr cmd, set flag */
 setFLG (dev);
@@ -258,9 +267,10 @@ UNIT *uptr = dptr->units;
 hp_enbdis_pair (&ipli_dev, &iplo_dev);			/* make pair cons */
 dibp->cmd = dibp->ctl = 0;				/* clear cmd, ctl */
 dibp->flg = dibp->fbf = 1;				/* set flg, fbf */
-uptr->buf = uptr->HOLD = 0;
+uptr->IBUF = uptr->OBUF = 0;				/* clr buffers */
 if (uptr->flags & UNIT_ATT) sim_activate (uptr, ipl_ptime);
 else sim_cancel (uptr);					/* deactivate unit */
+uptr->flags = uptr->flags & ~UNIT_HOLD;
 return SCPE_OK;
 }
 
@@ -305,8 +315,8 @@ else {	if (ipa != 0) return SCPE_ARG;
 	uptr->flags = uptr->flags & ~UNIT_ACTV;
 	uptr->LSOCKET = newsock;
 	uptr->DSOCKET = 0;  }
-uptr->buf = uptr->HOLD = 0;
-uptr->flags = (uptr->flags | UNIT_ATT) & ~UNIT_ESTB;	/* no more errors */
+uptr->IBUF = uptr->OBUF = 0;
+uptr->flags = (uptr->flags | UNIT_ATT) & ~(UNIT_ESTB | UNIT_HOLD);
 tptr = malloc (strlen (cptr) + 1);			/* get string buf */
 if (tptr == NULL) {					/* no memory? */
 	ipl_detach (uptr);				/* close sockets */
diff --git a/Interdata/id16_cpu.c b/Interdata/id16_cpu.c
index dfd4c606..d7c28260 100644
--- a/Interdata/id16_cpu.c
+++ b/Interdata/id16_cpu.c
@@ -23,6 +23,8 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   07-Feb-03	RMS	Fixed bug in SETM, SETMR (found by Mark Pizzolato)
+
    The register state for the Interdata 16b CPU is:
 
    R[0:F]<0:15>		general registers
@@ -1158,7 +1160,7 @@ case 0x53:						/* SETM - RXH */
 	    break;  }
 	t = (t & ~PSW_MAP) | (map << PSW_V_MAP);	/* insert map */
 	newPSW (t);					/* load new PSW */
-	CC_GL_16 (rslt);				/* set G,L */
+	CC_GL_16 (R[r1]);				/* set G,L */
 	break;
 
 /* I/O instructions */
diff --git a/Interdata/id32_cpu.c b/Interdata/id32_cpu.c
index 3a0b204d..5922d606 100644
--- a/Interdata/id32_cpu.c
+++ b/Interdata/id32_cpu.c
@@ -1987,6 +1987,8 @@ IOWriteB (addr, val & 0xFF);
 return SCPE_OK;
 }
 
+/* Change memory size */
+
 t_stat cpu_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
 {
 uint32 mc = 0;
diff --git a/NOVA/nova_cpu.c b/NOVA/nova_cpu.c
index e97fe5f2..b61d9216 100644
--- a/NOVA/nova_cpu.c
+++ b/NOVA/nova_cpu.c
@@ -1,6 +1,6 @@
 /* nova_cpu.c: NOVA CPU simulator
 
-   Copyright (c) 1993-2002, Robert M. Supnik
+   Copyright (c) 1993-2003, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    cpu		Nova central processor
 
+   19-Jan-03	RMS	Changed CMASK to CDMASK for Apple Dev Kit conflict
    03-Oct-02	RMS	Added DIB infrastructure
    30-Dec-01	RMS	Added old PC queue
    07-Dec-01	RMS	Revised to use breakpoint package
@@ -391,21 +392,21 @@ if (IR & I_OPR) {					/* operate? */
 	    src = src ^ DMASK;
 	    break;
 	case 1:						/* NEG */
-	    src = ((src ^ DMASK) + 1) & CMASK;
+	    src = ((src ^ DMASK) + 1) & CDMASK;
 	    break;
 	case 2:						/* MOV */
 	    break;
 	case 3:						/* INC */
-	    src = (src + 1) & CMASK;
+	    src = (src + 1) & CDMASK;
 	    break;
 	case 4:						/* ADC */
-	    src = ((src ^ DMASK) + AC[dstAC]) & CMASK;
+	    src = ((src ^ DMASK) + AC[dstAC]) & CDMASK;
 	    break;
 	case 5:						/* SUB */
-	    src = ((src ^ DMASK) + AC[dstAC] + 1) & CMASK;
+	    src = ((src ^ DMASK) + AC[dstAC] + 1) & CDMASK;
 	    break;
 	case 6:						/* ADD */
-	    src = (src + AC[dstAC]) & CMASK;
+	    src = (src + AC[dstAC]) & CDMASK;
 	    break;
 	case 7:						/* AND */
 	    src = src & (AC[dstAC] | CBIT);
@@ -417,10 +418,10 @@ if (IR & I_OPR) {					/* operate? */
 	case 0:						/* nop */
 	    break;
 	case 1:						/* L */
-	    src = ((src << 1) | (src >> 16)) & CMASK;
+	    src = ((src << 1) | (src >> 16)) & CDMASK;
 	    break;
 	case 2:						/* R */
-	    src = ((src >> 1) | (src << 16)) & CMASK;
+	    src = ((src >> 1) | (src << 16)) & CDMASK;
 	    break;
 	case 3:						/* S */
 	    src = ((src & 0377) << 8) | ((src >> 8) & 0377) |
diff --git a/NOVA/nova_defs.h b/NOVA/nova_defs.h
index 15db1b2d..abbc40a7 100644
--- a/NOVA/nova_defs.h
+++ b/NOVA/nova_defs.h
@@ -1,6 +1,6 @@
 /* nova_defs.h: NOVA/Eclipse simulator definitions 
 
-   Copyright (c) 1993-2002, Robert M. Supnik
+   Copyright (c) 1993-2003, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   19-Jan-03	RMS	Changed CMASK to CDMASK for Apple Dev kit conflict
    03-Oct-02	RMS	Added device information structure
    22-Dec-00	RMS	Added Bruce Ray's second terminal support
    10-Dec-00	RMS	Added Charles Owen's Eclipse support
@@ -67,7 +68,7 @@
 #define SIGN		0100000				/* sign */
 #define DMASK		0177777				/* data mask */
 #define CBIT		(DMASK + 1)			/* carry bit */
-#define CMASK		(CBIT | DMASK)			/* carry + data */
+#define CDMASK		(CBIT | DMASK)			/* carry + data */
 
 /* Reserved memory locations */
 
diff --git a/NOVA/nova_doc.txt b/NOVA/nova_doc.txt
index 35667828..c3138c4d 100644
--- a/NOVA/nova_doc.txt
+++ b/NOVA/nova_doc.txt
@@ -1,14 +1,14 @@
 To:	Users
 From:	Bob Supnik
 Subj:	Nova Simulator Usage
-Date:	15-Nov-2002
+Date:	1-Feb-2003
 
 			COPYRIGHT NOTICE
 
 The following copyright notice applies to both the SIMH source and binary:
 
-   Original code published in 1993-2002, written by Robert M Supnik
-   Copyright (c) 1993-2002, Robert M Supnik
+   Original code published in 1993-2003, written by Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -383,6 +383,22 @@ The second terminal output implements these registers:
 
 2.3 Fixed Head Disk (DK)
 
+Fixed head disk options include the ability to set the number of platters
+to a fixed value between 1 and 8, or to autosize the number of platters
+from the attached file:
+
+	SET RF 1P		one platter (256K)
+	SET RF 2P		two platters (512K)
+	SET RF 3P		three platters (768K)
+	SET RF 4P		four platters (1024K)
+	SET RF 5P		five platters (1280K)
+	SET RF 6P		six platters (1536K)
+	SET RF 7P		seven platters (1792K)
+	SET RF 8P		eight platters (2048K)
+	SET RF AUTOSIZE		autosized on attach
+
+The default is 8P (maximum size).
+
 The fixed head disk controller implements these registers:
 
 	name		size	comments
diff --git a/NOVA/nova_dsk.c b/NOVA/nova_dsk.c
index d1283521..1c562763 100644
--- a/NOVA/nova_dsk.c
+++ b/NOVA/nova_dsk.c
@@ -1,6 +1,6 @@
 /* nova_dsk.c: 4019 fixed head disk simulator
 
-   Copyright (c) 1993-2002, Robert M. Supnik
+   Copyright (c) 1993-2003, Robert M. Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -40,15 +40,19 @@
 #include "nova_defs.h"
 #include <math.h>
 
+#define UNIT_V_AUTO	(UNIT_V_UF + 0)			/* autosize */
+#define UNIT_V_MSIZE	(UNIT_V_UF + 1)			/* dummy mask */
+#define UNIT_AUTO	(1 << UNIT_V_AUTO)
+#define UNIT_MSIZE	(1 << UNIT_V_MSIZE)
+
 /* Constants */
 
 #define DSK_NUMWD	256				/* words/sector */
 #define DSK_NUMSC	8				/* sectors/track */
 #define DSK_NUMTR	128				/* tracks/disk */
+#define DSK_DKSIZE	(DSK_NUMTR*DSK_NUMSC*DSK_NUMWD)	/* words/disk */
+#define DSK_AMASK	((DSK_NUMDK*DSK_NUMTR*DSK_NUMSC) - 1)	/* address mask */
 #define DSK_NUMDK	8				/* disks/controller */
-#define DSK_SCSIZE 	(DSK_NUMDK*DSK_NUMTR*DSK_NUMSC) /* sectors/drive */
-#define DSK_AMASK	(DSK_SCSIZE - 1)		/* address mask */
-#define DSK_SIZE	(DSK_SCSIZE * DSK_NUMWD)	/* words/drive */
 #define GET_DISK(x)	(((x) / (DSK_NUMSC * DSK_NUMTR)) & (DSK_NUMDK - 1))
 
 /* Parameters in the unit descriptor */
@@ -94,6 +98,8 @@ int32 dsk (int32 pulse, int32 code, int32 AC);
 t_stat dsk_svc (UNIT *uptr);
 t_stat dsk_reset (DEVICE *dptr);
 t_stat dsk_boot (int32 unitno, DEVICE *dptr);
+t_stat dsk_attach (UNIT *uptr, char *cptr);
+t_stat dsk_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
 
 /* DSK data structures
 
@@ -106,7 +112,7 @@ DIB dsk_dib = { DEV_DSK, INT_DSK, PI_DSK, &dsk };
 
 UNIT dsk_unit =
 	{ UDATA (&dsk_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF,
-		DSK_SIZE) };
+		DSK_NUMDK * DSK_DKSIZE) };
 
 REG dsk_reg[] = {
 	{ ORDATA (STAT, dsk_stat, 16) },
@@ -121,11 +127,23 @@ REG dsk_reg[] = {
 	{ FLDATA (STOP_IOE, dsk_stopioe, 0) },
 	{ NULL }  };
 
+MTAB dsk_mod[] = {
+	{ UNIT_MSIZE,  262144, NULL, "1P", &dsk_set_size },
+	{ UNIT_MSIZE,  524288, NULL, "2P", &dsk_set_size },
+	{ UNIT_MSIZE,  786432, NULL, "3P", &dsk_set_size },
+	{ UNIT_MSIZE, 1048576, NULL, "4P", &dsk_set_size },
+	{ UNIT_MSIZE, 1310720, NULL, "5P", &dsk_set_size },
+	{ UNIT_MSIZE, 1572864, NULL, "6P", &dsk_set_size },
+	{ UNIT_MSIZE, 1835008, NULL, "7P", &dsk_set_size },
+	{ UNIT_MSIZE, 2097152, NULL, "8P", &dsk_set_size },
+	{ UNIT_AUTO, UNIT_AUTO, "autosize", "AUTOSIZE", NULL },
+	{ 0 }  };
+
 DEVICE dsk_dev = {
-	"DK", &dsk_unit, dsk_reg, NULL,
+	"DK", &dsk_unit, dsk_reg, dsk_mod,
 	1, 8, 21, 1, 8, 16,
 	NULL, NULL, &dsk_reset,
-	&dsk_boot, NULL, NULL,
+	&dsk_boot, &dsk_attach, NULL,
 	&dsk_dib, DEV_DISABLE };
 
 /* IOT routine */
@@ -245,3 +263,35 @@ for (i = 0; i < BOOT_LEN; i++) M[BOOT_START + i] = boot_rom[i];
 saved_PC = BOOT_START;
 return SCPE_OK;
 }
+
+/* Attach routine */
+
+t_stat dsk_attach (UNIT *uptr, char *cptr)
+{
+int32 p, d;
+int32 ds_bytes = DSK_DKSIZE * sizeof (int16);
+
+if (uptr->flags & UNIT_AUTO) {
+	FILE *fp = fopen (cptr, "rb");
+	if (fp == NULL) return SCPE_OPENERR;
+	fseek (fp, 0, SEEK_END);
+	p = ftell (fp);
+	d = (p + ds_bytes - 1) / ds_bytes;
+	if (d == 0) d = 1;
+	if (d > DSK_NUMDK) d = DSK_NUMDK;
+	uptr->capac = d * DSK_DKSIZE;
+	fclose (fp);  }
+return attach_unit (uptr, cptr);
+}
+
+/* Change disk size */
+
+t_stat dsk_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
+{
+if ((val == 0) || (val > (DSK_NUMDK * DSK_DKSIZE)))
+	return SCPE_IERR;
+if (uptr->flags & UNIT_ATT) return SCPE_ALATT;
+uptr->capac = val;
+uptr->flags = uptr->flags & ~UNIT_AUTO;
+return SCPE_OK;
+}
diff --git a/PDP10/pdp10_rp.c b/PDP10/pdp10_rp.c
index f1794119..9b786c01 100644
--- a/PDP10/pdp10_rp.c
+++ b/PDP10/pdp10_rp.c
@@ -339,7 +339,7 @@ int32 rpiff = 0;					/* INTR flip/flop */
 int32 rp_stopioe = 1;					/* stop on error */
 int32 rp_swait = 10;					/* seek time */
 int32 rp_rwait = 10;					/* rotate time */
-int reg_in_drive[32] = {
+static int32 reg_in_drive[32] = {
  0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
@@ -972,7 +972,7 @@ return SCPE_OK;
 
 t_stat rp_attach (UNIT *uptr, char *cptr)
 {
-int drv, i, p;
+int32 drv, i, p;
 t_stat r;
 
 uptr->capac = drv_tab[GET_DTYPE (uptr->flags)].size;
diff --git a/PDP10/pdp10_tu.c b/PDP10/pdp10_tu.c
index fd5ac0c2..2bc26d77 100644
--- a/PDP10/pdp10_tu.c
+++ b/PDP10/pdp10_tu.c
@@ -1,6 +1,6 @@
 /* pdp10_tu.c - PDP-10 RH11/TM03/TU45 magnetic tape simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    tu		RH11/TM03/TU45 magtape
 
+   27-Jan-03	RMS	Changed to dynamically allocate buffer
    21-Nov-02	RMS	Fixed bug in bootstrap (reported by Michael Thompson)
 			Fixed bug in read (reported by Harris Newman)
    29-Sep-02	RMS	Added variable vector support
@@ -296,16 +297,17 @@ int32 tuiff = 0;					/* INTR flip/flop */
 int32 tu_time = 10;					/* record latency */
 int32 tu_stopioe = 1;					/* stop on error */
 int32 tu_log = 0;					/* debug */
-int reg_in_fmtr[32] = {					/* reg in formatter */
+int32 reg_in_fmtr[32] = {				/* reg in formatter */
  0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
-int reg_in_fmtr1[32] = {				/* rmr if write + go */
+int32 reg_in_fmtr1[32] = {				/* rmr if write + go */
  0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
-int fmt_test[16] = {					/* fmt bytes/10 wd */
+int32 fmt_test[16] = {					/* fmt bytes/10 wd */
  5, 0, 5, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-int den_test[8] = {					/* valid densities */
+int32 den_test[8] = {					/* valid densities */
  0, 0, 0, 1, 1, 0, 0, 0 };
+static uint8 *xbuf = NULL;				/* xfer buffer */
 
 t_stat tu_rd (int32 *data, int32 PA, int32 access);
 t_stat tu_wr (int32 data, int32 PA, int32 access);
@@ -682,7 +684,6 @@ int32 ba, fc, wc, drv, mpa10, vpn;
 d10 val, v[4];
 t_mtrlnt abc, tbc;
 static t_mtrlnt bceof = { MTR_TMK };
-static uint8 xbuf[XBUFLNT + 4];
 
 drv = uptr - tu_dev.units;				/* get drive # */
 pnu = MT_TST_PNU (uptr);				/* get pos not upd */
@@ -968,6 +969,8 @@ for (u = 0; u < TU_NUMDR; u++) {			/* loop thru units */
 	MT_CLR_PNU (uptr);				/* clear pos flag */
 	sim_cancel (uptr);				/* cancel activity */
 	uptr->USTAT = 0;  }
+if (xbuf == NULL) xbuf = calloc (XBUFLNT + 4, sizeof (uint8));
+if (xbuf == NULL) return SCPE_MEM;
 return SCPE_OK;
 }
 
diff --git a/PDP11/pdp11_cpu.c b/PDP11/pdp11_cpu.c
index 44e00682..4b704180 100644
--- a/PDP11/pdp11_cpu.c
+++ b/PDP11/pdp11_cpu.c
@@ -25,6 +25,8 @@
 
    cpu		PDP-11 CPU (J-11 microprocessor)
 
+   01-Feb-03	RMS	Changed R display to follow PSW<rs>, added SP display
+   19-Jan-03	RMS	Changed mode definitions for Apple Dev Kit conflict
    05-Jan-03	RMS	Added memory size restore support
    17-Oct-02	RMS	Fixed bug in examine/deposit (found by Hans Pufal)
    08-Oct-02	RMS	Revised to build dib_tab dynamically
@@ -315,6 +317,7 @@ t_stat MMR3_rd (int32 *data, int32 addr, int32 access);
 t_stat MMR3_wr (int32 data, int32 addr, int32 access);
 t_stat ubm_rd (int32 *data, int32 addr, int32 access);
 t_stat ubm_wr (int32 data, int32 addr, int32 access);
+void set_r_display (int32 rs, int32 cm);
 
 extern t_stat build_dib_tab (int32 ubm);
 extern t_stat show_iospace (FILE *st, UNIT *uptr, int32 val, void *desc);
@@ -369,15 +372,22 @@ REG cpu_reg[] = {
 	{ ORDATA (R3, REGFILE[3][0], 16) },
 	{ ORDATA (R4, REGFILE[4][0], 16) },
 	{ ORDATA (R5, REGFILE[5][0], 16) },
+	{ ORDATA (SP, STACKFILE[MD_KER], 16) },
+	{ ORDATA (R00, REGFILE[0][0], 16) },
+	{ ORDATA (R01, REGFILE[1][0], 16) },
+	{ ORDATA (R02, REGFILE[2][0], 16) },
+	{ ORDATA (R03, REGFILE[3][0], 16) },
+	{ ORDATA (R04, REGFILE[4][0], 16) },
+	{ ORDATA (R05, REGFILE[5][0], 16) },
 	{ ORDATA (R10, REGFILE[0][1], 16) },
 	{ ORDATA (R11, REGFILE[1][1], 16) },
 	{ ORDATA (R12, REGFILE[2][1], 16) },
 	{ ORDATA (R13, REGFILE[3][1], 16) },
 	{ ORDATA (R14, REGFILE[4][1], 16) },
 	{ ORDATA (R15, REGFILE[5][1], 16) },
-	{ ORDATA (KSP, STACKFILE[KERNEL], 16) },
-	{ ORDATA (SSP, STACKFILE[SUPER], 16) },
-	{ ORDATA (USP, STACKFILE[USER], 16) },
+	{ ORDATA (KSP, STACKFILE[MD_KER], 16) },
+	{ ORDATA (SSP, STACKFILE[MD_SUP], 16) },
+	{ ORDATA (USP, STACKFILE[MD_USR], 16) },
 	{ ORDATA (PSW, PSW, 16) },
 	{ GRDATA (CM, PSW, 8, 2, PSW_V_CM) },
 	{ GRDATA (PM, PSW, 8, 2, PSW_V_PM) },
@@ -632,11 +642,11 @@ if (abortval != 0) {
 	trap_req = trap_req | abortval;			/* or in trap flag */
 	if ((trapea > 0) && (stop_vecabort)) reason = STOP_VECABORT;
 	if ((trapea < 0) && (stop_spabort)) reason = STOP_SPABORT;
-	if (trapea == ~KERNEL) {			/* kernel stk abort? */
+	if (trapea == ~MD_KER) {			/* kernel stk abort? */
 	    setTRAP (TRAP_RED);
 	    setCPUERR (CPUE_RED);
-	    STACKFILE[KERNEL] = 4;
-	    if (cm == KERNEL) SP = 4;  }  }
+	    STACKFILE[MD_KER] = 4;
+	    if (cm == MD_KER) SP = 4;  }  }
 
 /* Main instruction fetch/decode loop
 
@@ -701,8 +711,8 @@ if (trap_req) {						/* check traps, ints */
 		(N << PSW_V_N) | (Z << PSW_V_Z) |
 		(V << PSW_V_V) | (C << PSW_V_C);
 	oldrs = rs;
-	src = ReadW (trapea | calc_ds (KERNEL));
-	src2 = ReadW ((trapea + 2) | calc_ds (KERNEL));
+	src = ReadW (trapea | calc_ds (MD_KER));
+	src2 = ReadW ((trapea + 2) | calc_ds (MD_KER));
 	t = (src2 >> PSW_V_CM) & 03;
 	trapea = ~t;					/* flag pushes */
 	WriteW (PSW, ((STACKFILE[t] - 2) & 0177777) | calc_ds (t));
@@ -726,7 +736,7 @@ if (trap_req) {						/* check traps, ints */
 	isenable = calc_is (cm);
 	dsenable = calc_ds (cm);
 	trap_req = calc_ints (ipl, trap_req);
-	if ((SP < STKLIM) && (cm == KERNEL) &&
+	if ((SP < STKLIM) && (cm == MD_KER) &&
 	    (trapnum != TRAP_V_RED) && (trapnum != TRAP_V_YEL)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
@@ -766,14 +776,14 @@ case 000:
 		break;  }
 	    switch (IR) {				/* decode IR<2:0> */
 	    case 0:					/* HALT */
-	    	if ((cm == KERNEL) && ((MAINT & MAINT_HTRAP) == 0))
+	    	if ((cm == MD_KER) && ((MAINT & MAINT_HTRAP) == 0))
 		    reason = STOP_HALT;
 		else {
 		    setTRAP (TRAP_PRV);
 		    setCPUERR (CPUE_HALT);  }
 		break;
 	    case 1:					/* WAIT */
-		if (cm == KERNEL && wait_enable) wait_state = 1;
+		if (cm == MD_KER && wait_enable) wait_state = 1;
 		break;
 	    case 3:					/* BPT */
 		setTRAP (TRAP_BPT);
@@ -782,7 +792,7 @@ case 000:
 		setTRAP (TRAP_IOT);
 		break;
 	    case 5:					/* RESET */
-		if (cm == KERNEL) {
+		if (cm == MD_KER) {
 		    reset_all (1);
 		    PIRQ = 0;
 		    for (i = 0; i < IPL_HLVL; i++) int_req[i] = 0;
@@ -800,7 +810,7 @@ case 000:
 	    	src2 = ReadW (((SP + 2) & 0177777) | dsenable);
 		STACKFILE[cm] = SP = (SP + 4) & 0177777;
 		oldrs = rs;
-		if (cm == KERNEL) {
+		if (cm == MD_KER) {
 		    cm = (src2 >> PSW_V_CM) & 03;
 		    pm = (src2 >> PSW_V_PM) & 03;
 		    rs = (src2 >> PSW_V_RS) & 01;
@@ -848,7 +858,7 @@ case 000:
 		setTRAP (TRAP_ILL);
 		break;  }
 	    if (IR < 000240) {				/* SPL */
-		if (cm == KERNEL) ipl = IR & 07;
+		if (cm == MD_KER) ipl = IR & 07;
 		trap_req = calc_ints (ipl, trap_req);
 		break;  }				/* end if SPL */
 	    if (IR < 000260) {				/* clear CC */
@@ -925,7 +935,7 @@ case 000:
 		SP = (SP - 2) & 0177777;
 		if (update_MM) MMR1 = calc_MMR1 (0366);
 		WriteW (R[srcspec], SP | dsenable);
-		if ((SP < STKLIM) && (cm == KERNEL)) {
+		if ((SP < STKLIM) && (cm == MD_KER)) {
 		    setTRAP (TRAP_YEL);
 		    setCPUERR (CPUE_YEL);  }
 		R[srcspec] = PC;
@@ -1066,7 +1076,7 @@ case 000:
 		if ((dstspec == 6) && (cm != pm)) dst = STACKFILE[pm];
 		else dst = R[dstspec];  }
 	    else {
-	    	i = ((cm == pm) && (cm == USER))? calc_ds (pm): calc_is (pm);
+	    	i = ((cm == pm) && (cm == MD_USR))? calc_ds (pm): calc_is (pm);
 		dst = ReadW ((GeteaW (dstspec) & 0177777) | i);  }
 	    N = GET_SIGN_W (dst);
 	    Z = GET_Z (dst);
@@ -1074,7 +1084,7 @@ case 000:
 	    SP = (SP - 2) & 0177777;
 	    if (update_MM) MMR1 = calc_MMR1 (0366);
 	    WriteW (dst, SP | dsenable);
-	    if ((cm == KERNEL) && (SP < STKLIM)) {
+	    if ((cm == MD_KER) && (SP < STKLIM)) {
 		setTRAP (TRAP_YEL);
 		setCPUERR (CPUE_YEL);  }
 	    break;
@@ -1101,7 +1111,7 @@ case 000:
 /* Opcode 0: SOPs, continued */
 
 	case 070:					/* CSM */
-	    if (((MMR3 & MMR3_CSM) == 0) || (cm == KERNEL))
+	    if (((MMR3 & MMR3_CSM) == 0) || (cm == MD_KER))
 		setTRAP (TRAP_ILL);
 	    else {
 	    	dst = dstreg? R[dstspec]: ReadW (GeteaW (dstspec));
@@ -1109,12 +1119,12 @@ case 000:
 			(rs << PSW_V_RS) | (ipl << PSW_V_IPL) | 
 			(tbit << PSW_V_TBIT);
 		STACKFILE[cm] = SP;
-		WriteW (PSW, ((SP - 2) & 0177777) | calc_ds (SUPER));
-		WriteW (PC, ((SP - 4) & 0177777) | calc_ds (SUPER));
-		WriteW (dst, ((SP - 6) & 0177777) | calc_ds (SUPER));
+		WriteW (PSW, ((SP - 2) & 0177777) | calc_ds (MD_SUP));
+		WriteW (PC, ((SP - 4) & 0177777) | calc_ds (MD_SUP));
+		WriteW (dst, ((SP - 6) & 0177777) | calc_ds (MD_SUP));
 		SP = (SP - 6) & 0177777;
 		pm = cm;
-		cm = SUPER;
+		cm = MD_SUP;
 		tbit = 0;
 		isenable = calc_is (cm);
 		dsenable = calc_ds (cm);
@@ -1562,7 +1572,7 @@ case 010:
 
 	case 064:					/* MTPS */
 	    dst = dstreg? R[dstspec]: ReadB (GeteaB (dstspec));
-	    if (cm == KERNEL) {
+	    if (cm == MD_KER) {
 		ipl = (dst >> PSW_V_IPL) & 07;
 		trap_req = calc_ints (ipl, trap_req);  }
 	    N = (dst >> PSW_V_N) & 01;
@@ -1581,7 +1591,7 @@ case 010:
 	    SP = (SP - 2) & 0177777;
 	    if (update_MM) MMR1 = calc_MMR1 (0366);
 	    WriteW (dst, SP | dsenable);
-	    if ((cm == KERNEL) && (SP < STKLIM)) {
+	    if ((cm == MD_KER) && (SP < STKLIM)) {
 		setTRAP (TRAP_YEL);
 		setCPUERR (CPUE_YEL);  }
 	    break;
@@ -1717,6 +1727,7 @@ for (i = 0; i < 6; i++) REGFILE[i][rs] = R[i];
 STACKFILE[cm] = SP;
 saved_PC = PC & 0177777;
 pcq_r->qptr = pcq_p;					/* update pc q ptr */
+set_r_display (rs, cm);
 return reason;
 }
 
@@ -1790,14 +1801,14 @@ case 3:							/* @(R)+ */
 case 4:							/* -(R) */
 	adr = R[reg] = (R[reg] - 2) & 0177777;
 	if (update_MM) MMR1 = calc_MMR1 (0360 | reg);
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	return (adr | ds);
 case 5:							/* @-(R) */
 	adr = R[reg] = (R[reg] - 2) & 0177777;
 	if (update_MM) MMR1 = calc_MMR1 (0360 | reg);
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	adr = ReadW (adr | ds);
@@ -1840,14 +1851,14 @@ case 4:							/* -(R) */
 	delta = 1 + (reg >= 6);				/* 2 if R6, PC */
 	adr = R[reg] = (R[reg] - delta) & 0177777;
 	if (update_MM) MMR1 = calc_MMR1 ((((-delta) & 037) << 3) | reg);
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	return (adr | ds);
 case 5:							/* @-(R) */
 	adr = R[reg] = (R[reg] - 2) & 0177777;
 	if (update_MM) MMR1 = calc_MMR1 (0360 | reg);
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	adr = ReadW (adr | ds);
@@ -2120,9 +2131,9 @@ int32 relocC (int32 va, int32 sw)
 int32 mode, dbn, plf, apridx, apr, pa;
 
 if (MMR0 & MMR0_MME) {					/* if mmgt */
-	if (sw & SWMASK ('K')) mode = KERNEL;
-	else if (sw & SWMASK ('S')) mode = SUPER;
-	else if (sw & SWMASK ('U')) mode = USER;
+	if (sw & SWMASK ('K')) mode = MD_KER;
+	else if (sw & SWMASK ('S')) mode = MD_SUP;
+	else if (sw & SWMASK ('U')) mode = MD_USR;
 	else if (sw & SWMASK ('P')) mode = (PSW >> PSW_V_PM) & 03;
 	else mode = (PSW >> PSW_V_CM) & 03;
 	va = va | ((sw & SWMASK ('D'))? calc_ds (mode): calc_is (mode));
@@ -2394,6 +2405,7 @@ if (pcq_r) pcq_r->qptr = 0;
 else return SCPE_IERR;
 for (i = 0; i < UBM_LNT_LW; i++) ub_map[i] = 0;
 sim_brk_types = sim_brk_dflt = SWMASK ('E');
+set_r_display (0, MD_KER);
 return SCPE_OK;
 }
 
@@ -2476,3 +2488,17 @@ for (i = 0; (dptr = sim_devices[i]) != NULL; i++) {
 return SCPE_OK;
 }
 
+/* Set R, SP register display addresses */
+
+void set_r_display (int32 rs, int32 cm)
+{
+extern REG *find_reg (char *cptr, char **optr, DEVICE *dptr);
+REG *rptr;
+int32 i;
+
+rptr = find_reg ("R0", NULL, &cpu_dev);
+if (rptr == NULL) return;
+for (i = 0; i < 6; i++, rptr++) rptr->loc = (void *) &REGFILE[i][rs];
+rptr->loc = (void *) &STACKFILE[cm];
+return;
+}
diff --git a/PDP11/pdp11_defs.h b/PDP11/pdp11_defs.h
index 256a908f..6b31c3f0 100644
--- a/PDP11/pdp11_defs.h
+++ b/PDP11/pdp11_defs.h
@@ -1,6 +1,6 @@
 /* pdp11_defs.h: PDP-11 simulator definitions
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -26,6 +26,7 @@
    The author gratefully acknowledges the help of Max Burnet, Megan Gentry,
    and John Wilson in resolving questions about the PDP-11
 
+   19-Jan-03	RMS	Changed mode definitions for Apple Dev Kit conflict
    11-Nov-02	RMS	Changed log definitions to be VAX compatible
    10-Oct-02	RMS	Added vector information to DIB
 			Changed DZ11 vector to Unibus standard
@@ -71,10 +72,10 @@
 
 /* Protection modes */
 
-#define KERNEL		0
-#define SUPER		1
-#define UNUSED		2
-#define USER		3
+#define MD_KER		0
+#define MD_SUP		1
+#define MD_UND		2
+#define MD_USR		3
 
 /* I/O access modes */
 
diff --git a/PDP11/pdp11_doc.txt b/PDP11/pdp11_doc.txt
index 1b8b22c3..dfec8fc3 100644
--- a/PDP11/pdp11_doc.txt
+++ b/PDP11/pdp11_doc.txt
@@ -1,7 +1,7 @@
 To:	Users
 From:	Bob Supnik
 Subj:	PDP-11 Simulator Usage
-Date:	15-Jan-2003
+Date:	1-Feb-2003
 
 			COPYRIGHT NOTICE
 
@@ -203,8 +203,10 @@ control registers for the interrupt system.
 	name		size	comments
 
 	PC		16	program counter
-	R0..R5		16	R0..R5, first register set
-	R10..R15	16	R0..R5, second register set
+	R0..R5		16	R0..R5, current register set
+	SP		16	stack pointer, current mode
+	R00..R05	16	R0..R5, register set 0
+	R10..R15	16	R0..R5, register set 1
 	KSP		16	kernel stack pointer
 	SSP		16	supervisor stack pointer
 	USP		16	user stack pointer
diff --git a/PDP11/pdp11_fp.c b/PDP11/pdp11_fp.c
index 676fa6d6..50185330 100644
--- a/PDP11/pdp11_fp.c
+++ b/PDP11/pdp11_fp.c
@@ -1,6 +1,6 @@
 /* pdp11_fp.c: PDP-11 floating point simulator (32b version)
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   19-Jan-03	RMS	Changed mode definitions for Apple Dev Kit conflict
    08-Oct-02	RMS	Fixed macro definitions
    05-Jun-98	RMS	Fixed implementation specific shift bugs
    20-Apr-98	RMS	Fixed bug in MODf integer truncation
@@ -516,14 +517,14 @@ case 3:							/* @(R)+ */
 case 4:							/* -(R) */
 	adr = R[reg] = (R[reg] - len) & 0177777;
 	if (update_MM) MMR1 = (((-len) & 037) << 3) | reg;
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	return (adr | ds);
 case 5:							/* @-(R) */
 	adr = R[reg] = (R[reg] - 2) & 0177777;
 	if (update_MM) MMR1 = 0360 | reg;
-	if ((adr < STKLIM) && (reg == 6) && (cm == KERNEL)) {
+	if ((adr < STKLIM) && (reg == 6) && (cm == MD_KER)) {
 	    setTRAP (TRAP_YEL);
 	    setCPUERR (CPUE_YEL);  }
 	adr = ReadW (adr | ds);
diff --git a/PDP11/pdp11_rp.c b/PDP11/pdp11_rp.c
index 4399a108..cdd36a79 100644
--- a/PDP11/pdp11_rp.c
+++ b/PDP11/pdp11_rp.c
@@ -393,7 +393,7 @@ int32 rpiff = 0;					/* INTR flip/flop */
 int32 rp_stopioe = 1;					/* stop on error */
 int32 rp_swait = 10;					/* seek time */
 int32 rp_rwait = 10;					/* rotate time */
-static int reg_in_drive[32] = {
+static int32 reg_in_drive[32] = {
  0, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1,
  1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
@@ -1060,7 +1060,7 @@ return SCPE_OK;
 
 t_stat rp_attach (UNIT *uptr, char *cptr)
 {
-int drv, i, p;
+int32 drv, i, p;
 t_stat r;
 
 uptr->capac = drv_tab[GET_DTYPE (uptr->flags)].size;
diff --git a/PDP18B/pdp18b_cpu.c b/PDP18B/pdp18b_cpu.c
index 1e26ff1e..d9dddaa7 100644
--- a/PDP18B/pdp18b_cpu.c
+++ b/PDP18B/pdp18b_cpu.c
@@ -351,7 +351,7 @@ static const int32 api_ffo[256] = {
 
 static const int32 api_vec[API_HLVL][32] = {
  { ACH_PWRFL },						/* API 0 */
- { ACH_DTA, ACH_MTA, ACH_DRM, ACH_RF, ACH_RP },		/* API 1 */
+ { ACH_DTA, ACH_MTA, ACH_DRM, ACH_RF, ACH_RP, ACH_RB },	/* API 1 */
  { ACH_PTR, ACH_LPT, ACH_LPT },				/* API 2 */
  { ACH_CLK, ACH_TTI1, ACH_TTO1 }  };			/* API 3 */
 
diff --git a/PDP18B/pdp18b_defs.h b/PDP18B/pdp18b_defs.h
index 6cc81215..45ccff77 100644
--- a/PDP18B/pdp18b_defs.h
+++ b/PDP18B/pdp18b_defs.h
@@ -1,6 +1,6 @@
 /* pdp18b_defs.h: 18b PDP simulator definitions
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   04-Feb-03	RMS	Added RB09, LP09 support
    22-Nov-02	RMS	Added PDP-4 drum support
    05-Oct-02	RMS	Added DIB structure
    25-Jul-02	RMS	Added PDP-4 DECtape support
@@ -66,7 +67,9 @@
 	   	KF09A auto pri intr	PC09A paper tape reader and punch
 		KG09B mem extension	integral real time clock
 		KP09A power detection	Type 647D/E line printer (sixbit)
-		KX09A mem protection	RF09/RS09 fixed head disk
+		KX09A mem protection	LP09 line printer (ASCII)
+					RF09/RS09 fixed head disk
+					RB09 fixed head disk
 					TC59 magnetic tape
 					TC02/TU55 DECtape
 					LT09A second Teletype
@@ -74,8 +77,9 @@
    PDP15  128K	KE15 EAE		KSR-35 Teletype
 		KA15 auto pri intr	PC15 paper tape reader and punch
 		KF15 power detection	KW15 real time clock
-		KM15 mem protection	LP15 line printer
-		??KT15 mem relocation	RP15 disk pack
+		KM15 mem protection	LP09 line printer
+		??KT15 mem relocation	LP15 line printer
+					RP15 disk pack
 					RF15/RF09 fixed head disk
 					TC59D magnetic tape
 					TC15/TU56 DECtape
@@ -114,6 +118,8 @@
 #elif defined (PDP9)
 #define ADDRSIZE	15
 #define TYPE647		0				/* sixbit printer */
+#define LP09		0				/* ASCII printer */
+#define RB		0				/* fixed head disk */
 #define RF		0				/* fixed head disk */
 #define MTA		0				/* magtape */
 #define TC02		0				/* DECtape */
@@ -121,7 +127,8 @@
 #define BRMASK		0076000				/* bounds mask */
 #elif defined (PDP15)
 #define ADDRSIZE	17
-#define LP15		0				/* ASCII printer */
+#define LP09		0				/* ASCII printer */
+#define LP15		0				/* DMA printer */
 #define RF		0				/* fixed head disk */
 #define RP		0				/* disk pack */
 #define MTA		0				/* magtape */
@@ -184,6 +191,7 @@ typedef struct pdp18b_dib DIB;
 #define DEV_RP		063				/* RP15 */
 #define DEV_LPT		065				/* line printer */
 #define DEV_RF		070				/* RF09 */
+#define DEV_RB		071				/* RB09 */
 #define DEV_MT		073				/* magtape */
 #define DEV_DTA		075				/* dectape */
 
@@ -203,7 +211,7 @@ typedef struct pdp18b_dib DIB;
 	04	TC02/TC15		1
 	05	TC59D			1
 	06	drum			1	PDP-9 only
-	07	disk			1	PDP-9 only
+	07	RB09			1	PDP-9 only
 	10	paper tape reader	2
 	11	real time clock		3
 	12	power fail		0
@@ -250,22 +258,26 @@ typedef struct pdp18b_dib DIB;
 #define INT_V_DRM	2				/* drum */
 #define INT_V_RF	3				/* fixed head disk */
 #define INT_V_RP	4				/* disk pack */
+#define INT_V_RB	5				/* RB disk */
 
 #define INT_DTA		(1 << INT_V_DTA)
 #define INT_MTA		(1 << INT_V_MTA)
 #define INT_DRM		(1 << INT_V_DRM)
 #define INT_RF		(1 << INT_V_RF)
 #define INT_RP		(1 << INT_V_RP)
+#define INT_RB		(1 << INT_V_RB)
 
 #define API_DTA		1
 #define API_MTA		1
 #define API_DRM		1
 #define API_RF		1
 #define API_RP		1
+#define API_RB		1
 
 #define ACH_DTA		044
 #define ACH_MTA		045
 #define ACH_DRM		046
+#define ACH_RB		047
 #define ACH_RF		063
 #define ACH_RP		064
 
@@ -375,6 +387,7 @@ typedef struct pdp18b_dib DIB;
 #define IOS_PTPERR	0000400				/* punch empty */
 #define IOS_MTA		0000100				/* magtape */
 #define IOS_LPT		0000010				/* line printer */
+#define IOS_LPT1	0000000				/* not used */
 #endif
 
 /* Function prototypes */
diff --git a/PDP18B/pdp18b_doc.txt b/PDP18B/pdp18b_doc.txt
index 445c62ec..76ce61bf 100644
--- a/PDP18B/pdp18b_doc.txt
+++ b/PDP18B/pdp18b_doc.txt
@@ -1,14 +1,14 @@
 To:	Users
 From:	Bob Supnik
 Subj:	18b PDP Simulator Usage
-Date:	15-Nov-2002
+Date:	01-Feb-2003
 
 			COPYRIGHT NOTICE
 
 The following copyright notice applies to both the SIMH source and binary:
 
-   Original code published in 1993-2002, written by Robert M Supnik
-   Copyright (c) 1993-2002, Robert M Supnik
+   Original code published in 1993-2003, written by Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -61,6 +61,7 @@ sim/pdp18b/	pdp18b_defs.h
 		pdp18b_dt.c
 		pdp18b_lp.c
 		pdp18b_mt.c
+		pdp18b_rb.c
 		pdp18b_rf.c
 		pdp18b_rp.c
 		pdp18b_stddev.c
@@ -102,8 +103,10 @@ PDP-9	CPU		PDP-9 CPU with 32KW of memory
 	PTR,PTP		PC09A paper tape reader/punch
 	TTI,TTO		KSR 33 console terminal
 	TTI1,TTO1	LT09A second console terminal
+	LP9		LP09 line printer
 	LPT		Type 647E line printer
 	CLK		integral real-time clock
+	RB		RB09 fixed-head disk
 	RF		RF09/RS09 fixed-head disk
 	DT		TC02/TU55 DECtape
 	MT		TC59/TU10 magnetic tape
@@ -116,6 +119,7 @@ PDP-15	CPU		PDP-15 CPU with 32KW of memory
 	PTR,PTP		PC15 paper tape reader/punch
 	TTI,TTO		KSR 35 console terminal
 	TTI1,TTO1	LT15 second console terminal
+	LP9		LP09 line printer
 	LPT		LP15 line printer
 	CLK		integral real-time clock
 	RP		RP15/RP02 disk pack
@@ -239,9 +243,8 @@ BOOT -F PTR copies the funny format binary loader into memory and starts
 it running.
 
 The PTR ATTACH command recognizes one switch, -A for ASCII mode.  In
-ASCII mode, data returned by the read alphabetic command has the high
-order bit automatically set to 1.  This allows normal text files to be
-used as input to the paper tape reader.
+ASCII mode, data returned by the read alphabetic command has even parity.
+This allows normal text files to be used as input to the paper tape reader.
 
 The paper tape reader implements these registers:
 
@@ -337,13 +340,19 @@ implements these registers:
 	POS		32	number of chararacters output
 	TIME		24	time from I/O initiation to interrupt
 
-2.2.5 Line Printer (LPT)
+2.2.5 Line Printers (LPT, LP9)
 
-The line printer (LPT) writes data to a disk file.  The POS register
-specifies the number of the next data item to be written.  Thus,
-by changing POS, the user can backspace or advance the printer.
+The line printers (LPT, LP9) write data to a disk file.  The POS
+register specifies the number of the next data item to be written.
+Thus, by changing POS, the user can backspace or advance the printer.
 
-The PDP-4 uses a Type 62 printer controller, with these registers:
+LPT is the "default" line printer for a CPU: Type 62 for the PDP-4,
+Type 647 for the PDP-7 and PDP-9, and LP15 for the PDP-15.  LP9 is
+the LP09 line printer controller for the PDP-9.  It may be needed
+on the PDP-15 to run certain software packages.  LP9 is disabled by
+default.
+
+The Type 62 printer controller implements these registers:
 
 	name		size	comments
 
@@ -357,8 +366,7 @@ The PDP-4 uses a Type 62 printer controller, with these registers:
 	STOP_IOE	1	stop on I/O error
 	LBUF[0:119]	8	line buffer
 
-The PDP-7 and PDP-9 use a Type 647 printer controller, with these
-registers:
+The Type 647 printer controller implements these registers:
 
 	name		size	comments
 
@@ -373,7 +381,19 @@ registers:
 	STOP_IOE	1	stop on I/O error
 	LBUF[0:119]	8	line buffer
 
-The PDP-15 uses an LP15 printer controller, with these registers:
+The LP09 printer controller implements these registers:
+
+	name		size	comments
+
+	BUF		7	output character
+	INT		1	interrupt pending flag
+	DONE		1	device done flag
+	ENABLE		1	interrupt enable
+	ERR		1	error flag
+	POS		32	position in the output file
+	TIME		24	time from I/O initiation to interrupt
+
+The LP15 printer controller implements these registers:
 
 	name		size	comments
 
@@ -388,7 +408,7 @@ The PDP-15 uses an LP15 printer controller, with these registers:
 	STOP_IOE	1	stop on I/O error
 	LBUF[0:131]	8	line buffer
 
-For all three models, error handling is as follows:
+For all printers, error handling is as follows:
 
 	error	     STOP_IOE	processed as
 
@@ -519,16 +539,66 @@ Error handling is as follows:
 Drum data files are buffered in memory; therefore, end of file and OS
 I/O errors cannot occur.
 
+2.5 RB09 Fixed Head Disk (RB)
+
+The RB09 was an early fixed-head disk for the PDP-9.  It was superceded
+by the RF09/RS09.  It is disabled by default.
+
+The RB09 implements these registers:
+
+	name		size	comments
+
+	STA		18	status
+	DA		20	current disk address
+	WC		16	word count
+	MA		15	memory address
+	INT		1	interrupt pending flag
+	WLK		20	write lock switches for track groups,
+				10 tracks per group
+	TIME		24	rotational delay, per word
+	BURST		1	burst flag
+	STOP_IOE	1	stop on I/O error
+
+The RB09 is a data break device.  If BURST = 0, word transfers are
+scheduled individually; if BURST = 1, the entire transfer occurs in
+a single data break.
+
+Error handling is as follows:
+
+	error	     STOP_IOE	processed as
+
+	not attached	1	report error and stop
+			0	disk not ready
+
+RB09 data files are buffered in memory; therefore, end of file and OS
+I/O errors cannot occur.
+
 2.5 RF09/RF15/RS09 Fixed Head Disk (RF)
 
+RF09/RF15 options include the ability to set the number of platters
+to a fixed value between 1 and 8, or to autosize the number of platters
+from the attached file:
+
+	SET RF 1P		one platter (256K)
+	SET RF 2P		two platters (512K)
+	SET RF 3P		three platters (768K)
+	SET RF 4P		four platters (1024K)
+	SET RF 5P		five platters (1280K)
+	SET RF 6P		six platters (1536K)
+	SET RF 7P		seven platters (1792K)
+	SET RF 8P		eight platters (2048K)
+	SET RF AUTOSIZE		autosized on attach
+
+The default is AUTOSIZE.
+
 The RF09/RF15 implements these registers:
 
 	name		size	comments
 
 	STA		18	status
 	DA		21	current disk address
-	MA		18	memory address (in memory)
 	WC		18	word count (in memory)
+	CA		18	memory address (in memory)
 	BUF		18	data buffer (diagnostic only)
 	INT		1	interrupt pending flag
 	WLK[0:7]	16	write lock switches for disks 0-7
@@ -627,7 +697,7 @@ The magnetic tape controller implements these registers:
 
 	CMD		18	command
 	STA		18	main status
-	MA		18	memory address (in memory)
+	CA		18	memory address (in memory)
 	WC		18	word count (in memory)
 	INT		1	interrupt pending flag
 	STOP_IOE	1	stop on I/O error
diff --git a/PDP18B/pdp18b_lp.c b/PDP18B/pdp18b_lp.c
index bb23db34..030a41f9 100644
--- a/PDP18B/pdp18b_lp.c
+++ b/PDP18B/pdp18b_lp.c
@@ -1,6 +1,6 @@
 /* pdp18b_lp.c: 18b PDP's line printer simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,10 +23,12 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
-   lpt		(PDP-4) Type 62 line printer
-		(PDP-7,9) Type 647 line printer
-		(PDP-15) LP15 line printer
+   lp62		(PDP-4)    Type 62 line printer
+   lp647	(PDP-7,9)  Type 647 line printer
+   lp09		(PDP-9,15) LP09 line printer
+   lp15		(PDP-15)   LP15 line printer
 
+   05-Feb-03	RMS	Added LP09, fixed conditionalization
    05-Oct-02	RMS	Added DIB, device number support
    30-May-02	RMS	Widened POS to 32b
    03-Feb-02	RMS	Fixed typo (found by Robert Alan Byer)
@@ -40,282 +42,188 @@
 */
 
 #include "pdp18b_defs.h"
-
-DEVICE lpt_dev;
-int32 lpt65 (int32 pulse, int32 AC);
-int32 lpt66 (int32 pulse, int32 AC);
-int32 lpt_iors (void);
-t_stat lpt_svc (UNIT *uptr);
-t_stat lpt_reset (DEVICE *dptr);
-
 extern int32 int_hwre[API_HLVL+1];
 
-DIB lpt_dib = { DEV_LPT, 2, &lpt_iors, { &lpt65, &lpt66 } };
-
-UNIT lpt_unit = {
-	UDATA (&lpt_svc, UNIT_SEQ+UNIT_ATTABLE, 0), SERIAL_OUT_WAIT };
-
-MTAB lpt_mod[] = {
-	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
-	{ 0 } };
-
 #if defined (TYPE62)
 
+/* Type 62 line printer */
+
+#define LP62_BSIZE	120				/* line size */
 #define BPTR_MAX	40				/* pointer max */
-#define LPT_BSIZE	120				/* line size */
 #define BPTR_MASK	077				/* buf ptr max */
-int32 lpt_iot = 0, lpt_stopioe = 0, bptr = 0;
-char lpt_buf[LPT_BSIZE + 1] = { 0 };
 
-/* Type 62 LPT data structures
-
-   lpt_dev	LPT device descriptor
-   lpt_unit	LPT unit
-   lpt_reg	LPT register list
-*/
-
-REG lpt_reg[] = {
-	{ ORDATA (BUF, lpt_unit.buf, 8) },
-	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
-	{ FLDATA (DONE, int_hwre[API_LPT], INT_V_LPT) },
-	{ FLDATA (SPC, int_hwre[API_LPTSPC], INT_V_LPTSPC) },
-	{ DRDATA (BPTR, bptr, 6) },
-	{ ORDATA (STATE, lpt_iot, 6), REG_HRO },
-	{ DRDATA (POS, lpt_unit.pos, 32), PV_LEFT },
-	{ DRDATA (TIME, lpt_unit.wait, 24), PV_LEFT },
-	{ FLDATA (STOP_IOE, lpt_stopioe, 0) },
-	{ BRDATA (LBUF, lpt_buf, 8, 8, LPT_BSIZE) },
-	{ ORDATA (DEVNO, lpt_dib.dev, 6), REG_HRO },
-	{ NULL }  };
-
-DEVICE lpt_dev = {
-	"LPT", &lpt_unit, lpt_reg, lpt_mod,
-	1, 10, 31, 1, 8, 8,
-	NULL, NULL, &lpt_reset,
-	NULL, NULL, NULL,
-	&lpt_dib, DEV_DISABLE };
-
-/* Type 62 line printer: IOT routines */
-
-int32 lpt65 (int32 pulse, int32 AC)
-{
-int32 i;
-
-static const char lpt_trans[64] = {
+int32 lp62_iot = 0;					/* saved state */
+int32 lp62_stopioe = 0;
+int32 lp62_bp = 0;					/* buffer ptr */
+char lp62_buf[LP62_BSIZE + 1] = { 0 };
+static const char lp62_trans[64] = {
 	' ','1','2','3','4','5','6','7','8','9','\'','~','#','V','^','<',
 	'0','/','S','T','U','V','W','X','Y','Z','"',',','>','^','-','?',
 	'o','J','K','L','M','N','O','P','Q','R','$','=','-',')','-','(',
 	'_','A','B','C','D','E','F','G','H','I','*','.','+',']','|','[' };
+static const char *lp62_cc[] = {
+	"\n",
+	"\n\n",
+	"\n\n\n",
+	"\n\n\n\n\n\n",
+	"\n\n\n\n\n\n\n\n\n\n\n",
+	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n",
+	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n",
+	"\f" };
 
-if ((pulse & 001) && TST_INT (LPT)) AC = IOT_SKP | AC;	/* LPSF */
-if ((pulse & 042) == 002) CLR_INT (LPT);		/* LPCF */
-if (((pulse & 042) == 042) && (bptr < BPTR_MAX)) {	/* LPLD */
-	i = bptr * 3;					/* cvt to chr ptr */
-	lpt_buf[i] = lpt_trans[(AC >> 12) & 077];
-	lpt_buf[i + 1] = lpt_trans[(AC >> 6) & 077];
-	lpt_buf[i + 2] = lpt_trans[AC & 077];
-	bptr = (bptr + 1) & BPTR_MASK;  }
-if (pulse & 004) {					/* LPSE */
-	sim_activate (&lpt_unit, lpt_unit.wait);  }	/* activate */
+DEVICE lp62_dev;
+int32 lp62_65 (int32 pulse, int32 AC);
+int32 lp62_66 (int32 pulse, int32 AC);
+int32 lp62_iors (void);
+t_stat lp62_svc (UNIT *uptr);
+t_stat lp62_reset (DEVICE *dptr);
+
+/* Type 62 LPT data structures
+
+   lp62_dev	LPT device descriptor
+   lp62_unit	LPT unit
+   lp62_reg	LPT register list
+*/
+
+DIB lp62_dib = { DEV_LPT, 2, &lp62_iors, { &lp62_65, &lp62_66 } };
+
+UNIT lp62_unit = {
+	UDATA (&lp62_svc, UNIT_SEQ+UNIT_ATTABLE, 0), SERIAL_OUT_WAIT };
+
+REG lp62_reg[] = {
+	{ ORDATA (BUF, lp62_unit.buf, 8) },
+	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
+	{ FLDATA (DONE, int_hwre[API_LPT], INT_V_LPT) },
+	{ FLDATA (SPC, int_hwre[API_LPTSPC], INT_V_LPTSPC) },
+	{ DRDATA (BPTR, lp62_bp, 6) },
+	{ ORDATA (STATE, lp62_iot, 6), REG_HRO },
+	{ DRDATA (POS, lp62_unit.pos, 32), PV_LEFT },
+	{ DRDATA (TIME, lp62_unit.wait, 24), PV_LEFT },
+	{ FLDATA (STOP_IOE, lp62_stopioe, 0) },
+	{ BRDATA (LBUF, lp62_buf, 8, 8, LP62_BSIZE) },
+	{ ORDATA (DEVNO, lp62_dib.dev, 6), REG_HRO },
+	{ NULL }  };
+
+MTAB lp62_mod[] = {
+	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
+	{ 0 } };
+
+DEVICE lp62_dev = {
+	"LPT", &lp62_unit, lp62_reg, lp62_mod,
+	1, 10, 31, 1, 8, 8,
+	NULL, NULL, &lp62_reset,
+	NULL, NULL, NULL,
+	&lp62_dib, DEV_DISABLE };
+
+/* IOT routines */
+
+int32 lp62_65 (int32 pulse, int32 AC)
+{
+int32 i;
+
+if ((pulse & 01) && TST_INT (LPT)) AC = IOT_SKP | AC;	/* LPSF */
+if (pulse & 02) {
+	int32 sb = pulse & 060;				/* subopcode */
+	if (sb == 000) CLR_INT (LPT);			/* LPCF */
+	if ((sb == 040) && (lp62_bp < BPTR_MAX)) {	/* LPLD */
+	    i = lp62_bp * 3;				/* cvt to chr ptr */
+	    lp62_buf[i] = lp62_trans[(AC >> 12) & 077];
+	    lp62_buf[i + 1] = lp62_trans[(AC >> 6) & 077];
+	    lp62_buf[i + 2] = lp62_trans[AC & 077];
+	    lp62_bp = (lp62_bp + 1) & BPTR_MASK;  }
+	}
+if (pulse & 04)						/* LPSE */
+	sim_activate (&lp62_unit, lp62_unit.wait);	/* activate */
 return AC;
 }
 
-int32 lpt66 (int32 pulse, int32 AC)
+int32 lp62_66 (int32 pulse, int32 AC)
 {
-if ((pulse & 001) && TST_INT (LPTSPC))			/* LSSF */
+if ((pulse & 01) && TST_INT (LPTSPC))			/* LSSF */
 	AC = IOT_SKP | AC;
-if (pulse & 002) CLR_INT (LPTSPC);			/* LSCF */
-if (pulse & 004) {					/* LSPR */
-	lpt_iot = 020 | (AC & 07);			/* space, no print */
-	sim_activate (&lpt_unit, lpt_unit.wait);  }	/* activate */
+if (pulse & 02) CLR_INT (LPTSPC);			/* LSCF */
+if (pulse & 04) {					/* LSPR */
+	lp62_iot = 020 | (AC & 07);			/* space, no print */
+	sim_activate (&lp62_unit, lp62_unit.wait);  }	/* activate */
 return AC;
 }
 
 /* Unit service, printer is in one of three states
 
-   lpt_iot = 0		write buffer to file, set state to
-   lpt_iot = 10		write cr, then write buffer to file
-   lpt_iot = 2x		space command x, then set state to 0
+   lp62_iot = 0		write buffer to file, set state to
+   lp62_iot = 10	write cr, then write buffer to file
+   lp62_iot = 2x	space command x, then set state to 0
 */
 
-t_stat lpt_svc (UNIT *uptr)
+t_stat lp62_svc (UNIT *uptr)
 {
 int32 i;
-static const char *lpt_cc[] = {
-	"\n",
-	"\n\n",
-	"\n\n\n",
-	"\n\n\n\n\n\n",
-	"\n\n\n\n\n\n\n\n\n\n\n",
-	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n",
-	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n",
-	"\f" };
 
-if (lpt_iot & 020) {					/* space? */
+if (lp62_iot & 020) {					/* space? */
 	SET_INT (LPTSPC);				/* set flag */
-	if ((lpt_unit.flags & UNIT_ATT) == 0)		/* attached? */
-	    return IORETURN (lpt_stopioe, SCPE_UNATT);
-	fputs (lpt_cc[lpt_iot & 07], lpt_unit.fileref);	/* print cctl */
-	if (ferror (lpt_unit.fileref)) {		/* error? */
+	if ((uptr->flags & UNIT_ATT) == 0)		/* attached? */
+	    return IORETURN (lp62_stopioe, SCPE_UNATT);
+	fputs (lp62_cc[lp62_iot & 07], uptr->fileref);	/* print cctl */
+	if (ferror (uptr->fileref)) {			/* error? */
 	    perror ("LPT I/O error");
-	    clearerr (lpt_unit.fileref);
+	    clearerr (uptr->fileref);
 	    return SCPE_IOERR;  }
-	lpt_iot = 0;  }					/* clear state */
+	lp62_iot = 0;  }				/* clear state */
 else {	SET_INT (LPT);					/* print */
-	if ((lpt_unit.flags & UNIT_ATT) == 0)		/* attached? */
-	    return IORETURN (lpt_stopioe, SCPE_UNATT);
-	if (lpt_iot & 010) fputc ('\r', lpt_unit.fileref);
-	fputs (lpt_buf, lpt_unit.fileref);		/* print buffer */
-	if (ferror (lpt_unit.fileref)) {		/* test error */
+	if ((uptr->flags & UNIT_ATT) == 0)		/* attached? */
+	    return IORETURN (lp62_stopioe, SCPE_UNATT);
+	if (lp62_iot & 010) fputc ('\r', uptr->fileref);
+	fputs (lp62_buf, uptr->fileref);		/* print buffer */
+	if (ferror (uptr->fileref)) {			/* test error */
 	    perror ("LPT I/O error");
-	    clearerr (lpt_unit.fileref);
+	    clearerr (uptr->fileref);
 	    return SCPE_IOERR;  }
-	bptr = 0;
-	for (i = 0; i <= LPT_BSIZE; i++) lpt_buf[i] = 0; /* clear buffer */
-	lpt_iot = 010;  }				/* set state */
-lpt_unit.pos = ftell (lpt_unit.fileref);		/* update position */
+	lp62_bp = 0;
+	for (i = 0; i <= LP62_BSIZE; i++) lp62_buf[i] = 0; /* clear buffer */
+	lp62_iot = 010;  }				/* set state */
+uptr->pos = ftell (uptr->fileref);			/* update position */
 return SCPE_OK;
 }
 
 /* Reset routine */
 
-t_stat lpt_reset (DEVICE *dptr)
+t_stat lp62_reset (DEVICE *dptr)
 {
 int32 i;
 
 CLR_INT (LPT);						/* clear intrs */
 CLR_INT (LPTSPC);
-sim_cancel (&lpt_unit);					/* deactivate unit */
-bptr = 0;						/* clear buffer ptr */
-for (i = 0; i <= LPT_BSIZE; i++) lpt_buf[i] = 0;	/* clear buffer */
-lpt_iot = 0;						/* clear state */
+sim_cancel (&lp62_unit);				/* deactivate unit */
+lp62_bp = 0;						/* clear buffer ptr */
+for (i = 0; i <= LP62_BSIZE; i++) lp62_buf[i] = 0;	/* clear buffer */
+lp62_iot = 0;						/* clear state */
 return SCPE_OK;
 }
 
 /* IORS routine */
 
-int32 lpt_iors (void)
+int32 lp62_iors (void)
 {
 return	(TST_INT (LPT)? IOS_LPT: 0) |
 	(TST_INT (LPTSPC)? IOS_LPT1: 0);
 }
-
-#elif defined (TYPE647)
 
-#define LPT_BSIZE	120				/* line size */
-int32 lpt_done = 0, lpt_ie = 1, lpt_err = 0;
-int32 lpt_iot = 0, lpt_stopioe = 0, bptr = 0;
-char lpt_buf[LPT_BSIZE] = { 0 };
-
-t_stat lpt_attach (UNIT *uptr, char *cptr);
-t_stat lpt_detach (UNIT *uptr);
-
-/* Type 647 LPT data structures
-
-   lpt_dev	LPT device descriptor
-   lpt_unit	LPT unit
-   lpt_reg	LPT register list
-*/
-
-REG lpt_reg[] = {
-	{ ORDATA (BUF, lpt_unit.buf, 8) },
-	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
-	{ FLDATA (DONE, lpt_done, 0) },
-#if defined (PDP9)
-	{ FLDATA (ENABLE, lpt_ie, 0) },
 #endif
-	{ FLDATA (ERR, lpt_err, 0) },
-	{ DRDATA (BPTR, bptr, 7) },
-	{ ORDATA (SCMD, lpt_iot, 6), REG_HRO },
-	{ DRDATA (POS, lpt_unit.pos, 32), PV_LEFT },
-	{ DRDATA (TIME, lpt_unit.wait, 24), PV_LEFT },
-	{ FLDATA (STOP_IOE, lpt_stopioe, 0) },
-	{ BRDATA (LBUF, lpt_buf, 8, 8, LPT_BSIZE) },
-	{ ORDATA (DEVNO, lpt_dib.dev, 6), REG_HRO },
-	{ NULL }  };
-
-DEVICE lpt_dev = {
-	"LPT", &lpt_unit, lpt_reg, lpt_mod,
-	1, 10, 31, 1, 8, 8,
-	NULL, NULL, &lpt_reset,
-	NULL, &lpt_attach, &lpt_detach,
-	&lpt_dib, DEV_DISABLE };
 
-/* Type 647 line printer: IOT routines */
+#if defined (TYPE647)
 
-int32 lpt65 (int32 pulse, int32 AC)
-{
-int32 i, subp;
+/* Type 647 line printer */
 
-subp = (pulse >> 4) & 03;				/* subcode */
-if ((pulse & 001) && lpt_done) AC = IOT_SKP | AC;	/* LPSF */
-if (pulse & 002) {					/* pulse 02 */
-	lpt_done = 0;					/* clear done */
-	CLR_INT (LPT);					/* clear int req */
-	if (subp == 0) {				/* LPCB */
-	    for (i = 0; i < LPT_BSIZE; i++) lpt_buf[i] = 0;
-	    bptr = 0;					/* reset buf ptr */
-	    lpt_done = 1;				/* set done */
-	    if (lpt_ie) SET_INT (LPT);  }  }		/* set int */
-if (pulse & 004) {					/* LPDI */
-	switch (subp) {					/* case on subcode */
-	case 0:						/* LPDI */
-#if defined (PDP9)
-	    lpt_ie = 0;					/* clear int enable */
-	    CLR_INT (LPT);				/* clear int req */
-#endif
-	    break;
-	case 2:						/* LPB3 */
-	    if (bptr < LPT_BSIZE) {
-		lpt_buf[bptr] = lpt_buf[bptr] | ((AC >> 12) & 077);
-		bptr = bptr + 1;  }
-	case 1:						/* LPB2 */
-	    if (bptr < LPT_BSIZE) {
-		lpt_buf[bptr] = lpt_buf[bptr] | ((AC >> 6) & 077);
-		bptr = bptr + 1;  }
-	case 3:						/* LPB1 */
-	    if (bptr < LPT_BSIZE) {
-		lpt_buf[bptr] = lpt_buf[bptr] | (AC & 077);
-		bptr = bptr + 1;  }
-	    lpt_done = 1;				/* set done */
-	    if (lpt_ie) SET_INT (LPT);			/* set int */
-	    break;  }					/* end case */
-	}						/* end if pulse 4 */
-return AC;
-}
+#define LP647_BSIZE	120				/* line size */
 
-int32 lpt66 (int32 pulse, int32 AC)
-{
-if ((pulse & 001) && lpt_err) AC = IOT_SKP | AC;	/* LPSE */
-if (pulse & 002) {					/* LPCF */
-	lpt_done = 0;					/* clear done, int */
-	CLR_INT (LPT);  }
-if (pulse & 004) {
-	int32 subp = (pulse >> 4) & 03;			/* get subpulse */
-	if (subp < 3) {					/* LPLS, LPPB, LPPS */
-	    lpt_iot = (pulse & 060) | (AC & 07);	/* save parameters */
-	    sim_activate (&lpt_unit, lpt_unit.wait);  }	/* activate */
-#if defined (PDP9)
-	else {						/* LPEI */
-	    lpt_ie = 1;					/* set int enable */
-	    if (lpt_done) SET_INT (LPT);  }
-#endif
-	}						/* end if pulse 4 */
-return AC;
-}
-
-/* Unit service.  lpt_iot specifies the action to be taken
-
-   lpt_iot = 0x		print only
-   lpt_iot = 2x		space only, x is spacing command
-   lpt_iot = 4x		print then space, x is spacing command
-*/
-
-t_stat lpt_svc (UNIT *uptr)
-{
-int32 i;
-char pbuf[LPT_BSIZE + 1];
-static const char *lpt_cc[] = {
+int32 lp647_don = 0;					/* ready */
+int32 lp647_ie = 1;					/* int enable */
+int32 lp647_err = 0;					/* error */
+int32 lp647_iot = 0;					/* saved state */
+int32 lp647_stopioe = 0;
+int32 lp647_bp = 0;					/* buffer ptr */
+char lp647_buf[LP647_BSIZE] = { 0 };
+static const char *lp647_cc[] = {
 	"\n",
 	"\n\n",
 	"\n\n\n",
@@ -325,79 +233,355 @@ static const char *lpt_cc[] = {
 	"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n",
 	"\f" };
 
-lpt_done = 1;
-if (lpt_ie) SET_INT (LPT);				/* set flag */
-if ((lpt_unit.flags & UNIT_ATT) == 0) {			/* not attached? */
-	lpt_err = 1;					/* set error */
-	return IORETURN (lpt_stopioe, SCPE_UNATT);  }
-if ((lpt_iot & 020) == 0) {				/* print? */
-	for (i = 0; i < bptr; i++) 			/* translate buffer */
-	    pbuf[i] = lpt_buf[i] | ((lpt_buf[i] >= 040)? 0: 0100);
-	if ((lpt_iot & 060) == 0) pbuf[bptr++] = '\r';
-	for (i = 0; i < LPT_BSIZE; i++) lpt_buf[i] = 0;	/* clear buffer */
-	fwrite (pbuf, 1, bptr, lpt_unit.fileref);	/* print buffer */
-	if (ferror (lpt_unit.fileref)) {		/* error? */
+DEVICE lp647_dev;
+int32 lp647_65 (int32 pulse, int32 AC);
+int32 lp647_66 (int32 pulse, int32 AC);
+int32 lp647_iors (void);
+t_stat lp647_svc (UNIT *uptr);
+t_stat lp647_reset (DEVICE *dptr);
+t_stat lp647_attach (UNIT *uptr, char *cptr);
+t_stat lp647_detach (UNIT *uptr);
+
+/* Type 647 LPT data structures
+
+   lp647_dev	LPT device descriptor
+   lp647_unit	LPT unit
+   lp647_reg	LPT register list
+*/
+
+DIB lp647_dib = { DEV_LPT, 2, &lp647_iors, { &lp647_65, &lp647_66 } };
+
+UNIT lp647_unit = {
+	UDATA (&lp647_svc, UNIT_SEQ+UNIT_ATTABLE, 0), SERIAL_OUT_WAIT };
+
+REG lp647_reg[] = {
+	{ ORDATA (BUF, lp647_unit.buf, 8) },
+	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
+	{ FLDATA (DONE, lp647_don, 0) },
+#if defined (PDP9)
+	{ FLDATA (ENABLE, lp647_ie, 0) },
+#endif
+	{ FLDATA (ERR, lp647_err, 0) },
+	{ DRDATA (BPTR, lp647_bp, 7) },
+	{ ORDATA (SCMD, lp647_iot, 6), REG_HRO },
+	{ DRDATA (POS, lp647_unit.pos, 32), PV_LEFT },
+	{ DRDATA (TIME, lp647_unit.wait, 24), PV_LEFT },
+	{ FLDATA (STOP_IOE, lp647_stopioe, 0) },
+	{ BRDATA (LBUF, lp647_buf, 8, 8, LP647_BSIZE) },
+	{ ORDATA (DEVNO, lp647_dib.dev, 6), REG_HRO },
+	{ NULL }  };
+
+MTAB lp647_mod[] = {
+	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
+	{ 0 } };
+
+DEVICE lp647_dev = {
+	"LPT", &lp647_unit, lp647_reg, lp647_mod,
+	1, 10, 31, 1, 8, 8,
+	NULL, NULL, &lp647_reset,
+	NULL, &lp647_attach, &lp647_detach,
+	&lp647_dib, DEV_DISABLE };
+
+/* IOT routines */
+
+int32 lp647_65 (int32 pulse, int32 AC)
+{
+int32 i, sb;
+
+sb = pulse & 060;					/* subcode */
+if ((pulse & 01) && lp647_don) AC = IOT_SKP | AC;	/* LPSF */
+if (pulse & 02) {					/* pulse 02 */
+	lp647_don = 0;					/* clear done */
+	CLR_INT (LPT);					/* clear int req */
+	if (sb == 000) {				/* LPCB */
+	    for (i = 0; i < LP647_BSIZE; i++) lp647_buf[i] = 0;
+	    lp647_bp = 0;				/* reset buf ptr */
+	    lp647_don = 1;				/* set done */
+	    if (lp647_ie) SET_INT (LPT);  }		/* set int */
+	}
+if (pulse & 004) {					/* LPDI */
+	switch (sb) {					/* case on subcode */
+	case 000:					/* LPDI */
+#if defined (PDP9)
+	    lp647_ie = 0;				/* clear int enable */
+	    CLR_INT (LPT);				/* clear int req */
+#endif
+	    break;
+	case 040:					/* LPB3 */
+	    if (lp647_bp < LP647_BSIZE) {
+		lp647_buf[lp647_bp] = lp647_buf[lp647_bp] | ((AC >> 12) & 077);
+		lp647_bp = lp647_bp + 1;  }
+	case 020:					/* LPB2 */
+	    if (lp647_bp < LP647_BSIZE) {
+		lp647_buf[lp647_bp] = lp647_buf[lp647_bp] | ((AC >> 6) & 077);
+		lp647_bp = lp647_bp + 1;  }
+	case 060:					/* LPB1 */
+	    if (lp647_bp < LP647_BSIZE) {
+		lp647_buf[lp647_bp] = lp647_buf[lp647_bp] | (AC & 077);
+		lp647_bp = lp647_bp + 1;  }
+	    lp647_don = 1;				/* set done */
+	    if (lp647_ie) SET_INT (LPT);		/* set int */
+	    break;  }					/* end case */
+	}
+return AC;
+}
+
+int32 lp647_66 (int32 pulse, int32 AC)
+{
+if ((pulse & 01) && lp647_err) AC = IOT_SKP | AC;	/* LPSE */
+if (pulse & 02) {					/* LPCF */
+	lp647_don = 0;					/* clear done, int */
+	CLR_INT (LPT);  }
+if (pulse & 04) {
+	if ((pulse & 060) < 060) {			/* LPLS, LPPB, LPPS */
+	    lp647_iot = (pulse & 060) | (AC & 07);	/* save parameters */
+	    sim_activate (&lp647_unit, lp647_unit.wait);  }	/* activate */
+#if defined (PDP9)
+	else {						/* LPEI */
+	    lp647_ie = 1;				/* set int enable */
+	    if (lp647_don) SET_INT (LPT);  }
+#endif
+	}
+return AC;
+}
+
+/* Unit service.  lp647_iot specifies the action to be taken
+
+   lp647_iot = 0x		print only
+   lp647_iot = 2x		space only, x is spacing command
+   lp647_iot = 4x		print then space, x is spacing command
+*/
+
+t_stat lp647_svc (UNIT *uptr)
+{
+int32 i;
+char pbuf[LP647_BSIZE + 1];
+
+lp647_don = 1;
+if (lp647_ie) SET_INT (LPT);				/* set flag */
+if ((uptr->flags & UNIT_ATT) == 0) {			/* not attached? */
+	lp647_err = 1;					/* set error */
+	return IORETURN (lp647_stopioe, SCPE_UNATT);  }
+if ((lp647_iot & 020) == 0) {				/* print? */
+	for (i = 0; i < lp647_bp; i++) 			/* translate buffer */
+	    pbuf[i] = lp647_buf[i] | ((lp647_buf[i] >= 040)? 0: 0100);
+	if ((lp647_iot & 060) == 0) pbuf[lp647_bp++] = '\r';
+	for (i = 0; i < LP647_BSIZE; i++) lp647_buf[i] = 0;	/* clear buffer */
+	fwrite (pbuf, 1, lp647_bp, uptr->fileref);	/* print buffer */
+	if (ferror (uptr->fileref)) {			/* error? */
 	    perror ("LPT I/O error");
-	    clearerr (lpt_unit.fileref);
-	    bptr = 0;
+	    clearerr (uptr->fileref);
+	    lp647_bp = 0;
 	    return SCPE_IOERR;  }
-	bptr = 0;  }					/* clear buffer ptr */
-if (lpt_iot & 060) {					/* space? */
-	fputs (lpt_cc[lpt_iot & 07], lpt_unit.fileref);	/* write cctl */
-	if (ferror (lpt_unit.fileref)) {		/* error? */
+	lp647_bp = 0;  }				/* clear buffer ptr */
+if (lp647_iot & 060) {					/* space? */
+	fputs (lp647_cc[lp647_iot & 07], uptr->fileref);	/* write cctl */
+	if (ferror (uptr->fileref)) {			/* error? */
 	    perror ("LPT I/O error");
-	    clearerr (lpt_unit.fileref);
+	    clearerr (uptr->fileref);
 	    return SCPE_IOERR;  }  }
-lpt_unit.pos = ftell (lpt_unit.fileref);		/* update position */
+uptr->pos = ftell (uptr->fileref);			/* update position */
 return SCPE_OK;
 }
 
 /* Reset routine */
 
-t_stat lpt_reset (DEVICE *dptr)
+t_stat lp647_reset (DEVICE *dptr)
 {
 int32 i;
 
-lpt_done = 0;						/* clear done */
-lpt_err = (lpt_unit.flags & UNIT_ATT)? 0: 1;		/* compute error */
-lpt_ie = 1;						/* set enable */
+lp647_don = 0;						/* clear done */
+lp647_err = (lp647_unit.flags & UNIT_ATT)? 0: 1;	/* clr/set error */
+lp647_ie = 1;						/* set enable */
 CLR_INT (LPT);						/* clear int */
-sim_cancel (&lpt_unit);					/* deactivate unit */
-bptr = 0;						/* clear buffer ptr */
-lpt_iot = 0;						/* clear state */
-for (i = 0; i < LPT_BSIZE; i++) lpt_buf[i] = 0;		/* clear buffer */
+sim_cancel (&lp647_unit);				/* deactivate unit */
+lp647_bp = 0;						/* clear buffer ptr */
+lp647_iot = 0;						/* clear state */
+for (i = 0; i < LP647_BSIZE; i++) lp647_buf[i] = 0;	/* clear buffer */
 return SCPE_OK;
 }
 
 /* IORS routine */
 
-int32 lpt_iors (void)
+int32 lp647_iors (void)
 {
-return	(lpt_done? IOS_LPT: 0) | (lpt_err? IOS_LPT1: 0);
+return (lp647_don? IOS_LPT: 0) | (lp647_err? IOS_LPT1: 0);
 }
 
 /* Attach routine */
 
-t_stat lpt_attach (UNIT *uptr, char *cptr)
+t_stat lp647_attach (UNIT *uptr, char *cptr)
 {
 t_stat reason;
 
 reason = attach_unit (uptr, cptr);
-lpt_err = (lpt_unit.flags & UNIT_ATT)? 0: 1;		/* compute error */
+lp647_err = (lp647_unit.flags & UNIT_ATT)? 0: 1;	/* clr/set error */
 return reason;
 }
 
 /* Detach routine */
 
-t_stat lpt_detach (UNIT *uptr)
+t_stat lp647_detach (UNIT *uptr)
 {
-lpt_err = 1;
+lp647_err = 1;
 return detach_unit (uptr);
 }
-
-#elif defined (LP15)
 
-#define LPT_BSIZE	132				/* line size */
+#endif
+
+#if defined (LP09)
+
+/* LP09 line printer */
+
+#define LP09_BSIZE	132				/* line size */
+
+int32 lp09_don = 0;					/* ready */
+int32 lp09_err = 0;					/* error */
+int32 lp09_ie = 1;					/* int enable */
+int32 lp09_stopioe = 0;
+DEVICE lp09_dev;
+
+int32 lp09_66 (int32 pulse, int32 AC);
+int32 lp09_iors (void);
+t_stat lp09_svc (UNIT *uptr);
+t_stat lp09_reset (DEVICE *dptr);
+t_stat lp09_attach (UNIT *uptr, char *cptr);
+t_stat lp09_detach (UNIT *uptr);
+
+/* LP09 LPT data structures
+
+   lp09_dev	LPT device descriptor
+   lp09_unit	LPT unit
+   lp09_reg	LPT register list
+*/
+
+DIB lp09_dib = { DEV_LPT, 2, &lp09_iors, { NULL, &lp09_66 } };
+
+UNIT lp09_unit = {
+	UDATA (&lp09_svc, UNIT_SEQ+UNIT_ATTABLE, 0), SERIAL_OUT_WAIT };
+
+REG lp09_reg[] = {
+	{ ORDATA (BUF, lp09_unit.buf, 7) },
+	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
+	{ FLDATA (DONE, lp09_don, 0) },
+	{ FLDATA (ENABLE, lp09_ie, 0) },
+	{ FLDATA (ERR, lp09_err, 0) },
+	{ DRDATA (POS, lp09_unit.pos, 32), PV_LEFT },
+	{ DRDATA (TIME, lp09_unit.wait, 24), PV_LEFT },
+	{ FLDATA (STOP_IOE, lp09_stopioe, 0) },
+	{ ORDATA (DEVNO, lp09_dib.dev, 6), REG_HRO },
+	{ NULL }  };
+
+MTAB lp09_mod[] = {
+	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
+	{ 0 } };
+
+DEVICE lp09_dev = {
+	"LP9", &lp09_unit, lp09_reg, lp09_mod,
+	1, 10, 31, 1, 8, 8,
+	NULL, NULL, &lp09_reset,
+	NULL, &lp09_attach, &lp09_detach,
+	&lp09_dib, DEV_DISABLE | DEV_DIS };
+
+/* IOT routines */
+
+int32 lp09_66 (int32 pulse, int32 AC)
+{
+int32 sb = pulse & 060;					/* subopcode */
+
+if (pulse & 001) {
+	if ((sb == 000) && lp09_don) AC = IOT_SKP | AC;	/* LSDF */
+	if ((sb == 020) && lp09_err) AC = IOT_SKP | AC;	/* LSEF */
+	}
+if (pulse & 002) {
+	if (sb == 000) {				/* LSCF */
+	    lp09_don = 0;				/* clear done, int */
+	    CLR_INT (LPT);  }
+	else if (sb == 020) {				/* LPLD */
+	    lp09_don = 0;				/* clear done, int */
+	    CLR_INT (LPT);
+	    lp09_unit.buf = AC & 0177;			/* load char */
+	    if ((lp09_unit.buf == 015) || (lp09_unit.buf == 014) ||
+		(lp09_unit.buf == 012))
+		sim_activate (&lp09_unit, lp09_unit.wait);
+	    else AC = AC | (lp09_svc (&lp09_unit) << IOT_V_REASON);  }
+	}
+if (pulse & 004) {
+	if (sb == 000) {				/* LIOF */
+	    lp09_ie = 0;				/* clear int enab */
+	    CLR_INT (LPT);  }				/* clear int */
+	else if (sb == 040) {				/* LION */
+	    lp09_ie = 1;				/* set int enab */
+	    if (lp09_don) SET_INT (LPT);  }		/* if done, set int */
+	}
+return AC;
+}
+
+/* Unit service */
+
+t_stat lp09_svc (UNIT *uptr)
+{
+int32 c;
+
+lp09_don = 1;						/* set done */
+if (lp09_ie) SET_INT (LPT);				/* int enb? req int */
+if ((uptr->flags & UNIT_ATT) == 0) {			/* not attached? */
+	lp09_err = 1;					/* set error */
+	return IORETURN (lp09_stopioe, SCPE_UNATT);  }
+c = uptr->buf & 0177;					/* get char */
+if ((c == 0) || (c == 0177)) return SCPE_OK;		/* skip NULL, DEL */
+if (fputc (c, uptr->fileref) == EOF) {			/* print char */
+	perror ("LPT I/O error");
+	clearerr (uptr->fileref);
+	return SCPE_IOERR;  }
+uptr->pos = uptr->pos + 1;				/* update position */
+return SCPE_OK;
+}
+
+/* Reset routine */
+
+t_stat lp09_reset (DEVICE *dptr)
+{
+lp09_don = 0;						/* clear done */
+lp09_err = (lp09_unit.flags & UNIT_ATT)? 0: 1;		/* compute error */
+lp09_ie = 1;						/* set enable */
+CLR_INT (LPT);						/* clear int */
+return SCPE_OK;
+}
+
+/* IORS routine */
+
+int32 lp09_iors (void)
+{
+return (lp09_don? IOS_LPT: 0);
+}
+
+/* Attach routine */
+
+t_stat lp09_attach (UNIT *uptr, char *cptr)
+{
+t_stat reason;
+
+reason = attach_unit (uptr, cptr);
+lp09_err = (lp09_unit.flags & UNIT_ATT)? 0: 1;		/* clr/set error */
+return reason;
+}
+
+/* Detach routine */
+
+t_stat lp09_detach (UNIT *uptr)
+{
+lp09_err = 1;
+return detach_unit (uptr);
+}
+
+#endif
+
+#if defined (LP15)
+
+/* LP15 line printer */
+
+#define LP15_BSIZE	132				/* line size */
 #define LPT_WC		034				/* word count */
 #define LPT_CA		035				/* current addr */
 
@@ -414,76 +598,99 @@ return detach_unit (uptr);
 #define STA_CLR		0003777				/* always clear */
 
 extern int32 M[];
-int32 lpt_sta = 0, lpt_ie = 1, lpt_stopioe = 0;
-int32 mode = 0, lcnt = 0, bptr = 0;
-char lpt_buf[LPT_BSIZE] = { 0 };
+int32 lp15_sta = 0;
+int32 lp15_ie = 1;
+int32 lp15_stopioe = 0;
+int32 lp15_mode = 0;
+int32 lp15_lc = 0;
+int32 lp15_bp = 0;
+char lp15_buf[LP15_BSIZE] = { 0 };
 
-int32 lpt_updsta (int32 new);
+DEVICE lp15_dev;
+int32 lp15_65 (int32 pulse, int32 AC);
+int32 lp15_66 (int32 pulse, int32 AC);
+int32 lp15_iors (void);
+t_stat lp15_svc (UNIT *uptr);
+t_stat lp15_reset (DEVICE *dptr);
+
+int32 lp15_updsta (int32 new);
 
 /* LP15 LPT data structures
 
-   lpt_dev	LPT device descriptor
-   lpt_unit	LPT unit
-   lpt_reg	LPT register list
+   lp15_dev	LPT device descriptor
+   lp15_unit	LPT unit
+   lp15_reg	LPT register list
 */
 
-REG lpt_reg[] = {
-	{ ORDATA (STA, lpt_sta, 18) },
+DIB lp15_dib = { DEV_LPT, 2, &lp15_iors, { &lp15_65, &lp15_66 } };
+
+UNIT lp15_unit = {
+	UDATA (&lp15_svc, UNIT_SEQ+UNIT_ATTABLE, 0), SERIAL_OUT_WAIT };
+
+REG lp15_reg[] = {
+	{ ORDATA (STA, lp15_sta, 18) },
 	{ ORDATA (CA, M[LPT_CA], 18) },
 	{ FLDATA (INT, int_hwre[API_LPT], INT_V_LPT) },
-	{ FLDATA (ENABLE, lpt_ie, 0) },
-	{ DRDATA (LCNT, lcnt, 9) },
-	{ DRDATA (BPTR, bptr, 8) },
-	{ FLDATA (MODE, mode, 0) },
-	{ DRDATA (POS, lpt_unit.pos, 32), PV_LEFT },
-	{ DRDATA (TIME, lpt_unit.wait, 24), PV_LEFT },
-	{ FLDATA (STOP_IOE, lpt_stopioe, 0) },
-	{ BRDATA (LBUF, lpt_buf, 8, 8, LPT_BSIZE) },
-	{ ORDATA (DEVNO, lpt_dib.dev, 6), REG_HRO },
+	{ FLDATA (ENABLE, lp15_ie, 0) },
+	{ DRDATA (LCNT, lp15_lc, 9) },
+	{ DRDATA (BPTR, lp15_bp, 8) },
+	{ FLDATA (MODE, lp15_mode, 0) },
+	{ DRDATA (POS, lp15_unit.pos, 32), PV_LEFT },
+	{ DRDATA (TIME, lp15_unit.wait, 24), PV_LEFT },
+	{ FLDATA (STOP_IOE, lp15_stopioe, 0) },
+	{ BRDATA (LBUF, lp15_buf, 8, 8, LP15_BSIZE) },
+	{ ORDATA (DEVNO, lp15_dib.dev, 6), REG_HRO },
 	{ NULL }  };
 
-DEVICE lpt_dev = {
-	"LPT", &lpt_unit, lpt_reg, lpt_mod,
+MTAB lp15_mod[] = {
+	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
+	{ 0 } };
+
+DEVICE lp15_dev = {
+	"LPT", &lp15_unit, lp15_reg, lp15_mod,
 	1, 10, 31, 1, 8, 8,
-	NULL, NULL, &lpt_reset,
+	NULL, NULL, &lp15_reset,
 	NULL, NULL, NULL,
-	&lpt_dib, DEV_DISABLE };
+	&lp15_dib, DEV_DISABLE };
 
-/* LP15 line printer: IOT routines */
+/* IOT routines */
 
-int32 lpt65 (int32 pulse, int32 AC)
+int32 lp15_65 (int32 pulse, int32 AC)
 {
-int32 header;
+int32 header, sb;
 
-if (pulse == 001)					/* LPSF */
-	return (lpt_sta & (STA_ERR | STA_DON))? IOT_SKP + AC: AC;
-if ((pulse == 021) || (pulse == 041)) {			/* LPP1, LPPM */
-	header = M[(M[LPT_CA] + 1) & ADDRMASK];		/* get first word */
-	M[LPT_CA] = (M[LPT_CA] + 2) & 0777777;
-	mode = header & 1;				/* mode */
-	if (pulse == 041) lcnt = 1;			/* line count */
-	else lcnt = (header >> 9) & 0377;
-	if (lcnt == 0) lcnt = 256;
-	bptr = 0;					/* reset buf ptr */
-	sim_activate (&lpt_unit, lpt_unit.wait);  }	/* activate */
-if (pulse == 061) lpt_ie = 0;				/* LPDI */
-if (pulse == 042) return lpt_updsta (0);		/* LPOS, LPRS */
-if (pulse == 044) lpt_ie = 1;				/* LPEI */
-lpt_updsta (0);						/* update status */
+sb = pulse & 060;					/* subopcode */
+if (pulse & 01) {
+	if ((sb == 000) && (lp15_sta & (STA_ERR | STA_DON)))	/* LPSF */
+	    AC = IOT_SKP | AC;
+	else if ((sb == 020) || (sb == 040)) {		/* LPP1, LPPM */
+	    sim_activate (&lp15_unit, lp15_unit.wait);	/* activate */
+	    header = M[(M[LPT_CA] + 1) & ADDRMASK];	/* get first word */
+	    M[LPT_CA] = (M[LPT_CA] + 2) & 0777777;
+	    lp15_mode = header & 1;			/* mode */
+	    if (sb == 040) lp15_lc = 1;			/* line count */
+	    else lp15_lc = (header >> 9) & 0377;
+	    if (lp15_lc == 0) lp15_lc = 256;
+	    lp15_bp = 0;  }				/* reset buf ptr */
+	else if (sb == 060) lp15_ie = 0;		/* LPDI */
+	}
+if ((pulse & 02) && (sb == 040)) AC = AC | lp15_updsta (0);	/* LPOS, LPRS */
+if ((pulse & 04) && (sb == 040)) lp15_ie = 1;		/* LPEI */
+lp15_updsta (0);					/* update status */
 return AC;
 }
 
-int32 lpt66 (int32 pulse, int32 AC)
+int32 lp15_66 (int32 pulse, int32 AC)
 {
-if (pulse == 021) lpt_sta = lpt_sta & ~STA_DON;		/* LPCD */
-if (pulse == 041) lpt_sta = 0;				/* LPCF */
-lpt_updsta (0);						/* update status */
+if (pulse == 021) lp15_sta = lp15_sta & ~STA_DON;	/* LPCD */
+if (pulse == 041) lp15_sta = 0;				/* LPCF */
+lp15_updsta (0);					/* update status */
 return AC;
 }
 
 /* Unit service */
 
-t_stat lpt_svc (UNIT *uptr)
+t_stat lp15_svc (UNIT *uptr)
 {
 int32 i, ccnt, more, w0, w1;
 char c[5];
@@ -496,15 +703,15 @@ static const char *ctrl[040] = {
 	"\n\n\n\n\n\n\n\n\n\n", NULL, NULL, NULL,
 	NULL, NULL, NULL, "\r", NULL, NULL, NULL, NULL };
 
-if ((lpt_unit.flags & UNIT_ATT) == 0) {			/* not attached? */
-	lpt_updsta (STA_DON | STA_ALM);			/* set done, err */
-	return IORETURN (lpt_stopioe, SCPE_UNATT);  }
+if ((uptr->flags & UNIT_ATT) == 0) {			/* not attached? */
+	lp15_updsta (STA_DON | STA_ALM);		/* set done, err */
+	return IORETURN (lp15_stopioe, SCPE_UNATT);  }
 
 for (more = 1; more != 0; ) {				/* loop until ctrl */
 	w0 = M[(M[LPT_CA] + 1) & ADDRMASK];		/* get first word */
 	w1 = M[(M[LPT_CA] + 2) & ADDRMASK];		/* get second word */
 	M[LPT_CA] = (M[LPT_CA] + 2) & 0777777;		/* advance mem addr */
-	if (mode) {					/* unpacked? */
+	if (lp15_mode) {				/* unpacked? */
 	    c[0] = w0 & 0177;
 	    c[1] = w1 & 0177;
 	    ccnt = 2;  }
@@ -517,55 +724,55 @@ for (more = 1; more != 0; ) {				/* loop until ctrl */
 	    ccnt = 5;  }
 	for (i = 0; i < ccnt; i++) {			/* loop through */
 	    if ((c[i] <= 037) && ctrl[c[i]]) {		/* control char? */
-		fwrite (lpt_buf, 1, bptr, lpt_unit.fileref);
-		fputs (ctrl[c[i]], lpt_unit.fileref);
-		if (ferror (lpt_unit.fileref)) {	/* error? */
+		fwrite (lp15_buf, 1, lp15_bp, uptr->fileref);
+		fputs (ctrl[c[i]], uptr->fileref);
+		if (ferror (uptr->fileref)) {		/* error? */
 		    perror ("LPT I/O error");
-		    clearerr (lpt_unit.fileref);
-		    bptr = 0;
-		    lpt_updsta (STA_DON | STA_ALM);
+		    clearerr (uptr->fileref);
+		    lp15_bp = 0;
+		    lp15_updsta (STA_DON | STA_ALM);
 		    return SCPE_IOERR;  }
-		lpt_unit.pos = ftell (lpt_unit.fileref);
-		bptr = more = 0;  }
+		uptr->pos = ftell (uptr->fileref);
+		lp15_bp = more = 0;  }
 	    else {
-	    	if (bptr < LPT_BSIZE) lpt_buf[bptr++] = c[i];
-		else lpt_sta = lpt_sta | STA_OVF;  }  }  }
+	    	if (lp15_bp < LP15_BSIZE) lp15_buf[lp15_bp++] = c[i];
+		else lp15_sta = lp15_sta | STA_OVF;  }  }  }
 
-lcnt = lcnt - 1;					/* decr line count */
-if (lcnt) sim_activate (&lpt_unit, lpt_unit.wait);	/* more to do? */
-else lpt_updsta (STA_DON);				/* no, set done */
+lp15_lc = lp15_lc - 1;					/* decr line count */
+if (lp15_lc) sim_activate (&lp15_unit, uptr->wait);	/* more to do? */
+else lp15_updsta (STA_DON);				/* no, set done */
 return SCPE_OK;
 }
 
 /* Update status */
 
-int32 lpt_updsta (int32 new)
+int32 lp15_updsta (int32 new)
 {
-lpt_sta = (lpt_sta | new) & ~(STA_CLR | STA_ERR | STA_BUSY);
-if (lpt_sta & STA_EFLGS) lpt_sta = lpt_sta | STA_ERR;	/* update errors */
-if (sim_is_active (&lpt_unit)) lpt_sta = lpt_sta | STA_BUSY;
-if (lpt_ie && (lpt_sta & STA_DON)) SET_INT (LPT);
+lp15_sta = (lp15_sta | new) & ~(STA_CLR | STA_ERR | STA_BUSY);
+if (lp15_sta & STA_EFLGS) lp15_sta = lp15_sta | STA_ERR;	/* update errors */
+if (sim_is_active (&lp15_unit)) lp15_sta = lp15_sta | STA_BUSY;
+if (lp15_ie && (lp15_sta & STA_DON)) SET_INT (LPT);
 else CLR_INT (LPT);					/* update int */
-return lpt_sta;
+return lp15_sta;
 }
 
 /* Reset routine */
 
-t_stat lpt_reset (DEVICE *dptr)
+t_stat lp15_reset (DEVICE *dptr)
 {
-mode = lcnt = bptr = 0;					/* clear controls */
-sim_cancel (&lpt_unit);					/* deactivate unit */
-lpt_sta = 0;						/* clear status */
-lpt_ie = 1;						/* enable interrupts */
-lpt_updsta (0);						/* update status */
+lp15_mode = lp15_lc = lp15_bp = 0;			/* clear controls */
+sim_cancel (&lp15_unit);				/* deactivate unit */
+lp15_sta = 0;						/* clear status */
+lp15_ie = 1;						/* enable interrupts */
+lp15_updsta (0);					/* update status */
 return SCPE_OK;
 }
 
 /* IORS routine */
 
-int32 lpt_iors (void)
+int32 lp15_iors (void)
 {
-return ((lpt_sta & STA_DON)? IOS_LPT: 0);
+return ((lp15_sta & STA_DON)? IOS_LPT: 0);
 }
 
 #endif
diff --git a/PDP18B/pdp18b_mt.c b/PDP18B/pdp18b_mt.c
index 060c8630..cbec8261 100644
--- a/PDP18B/pdp18b_mt.c
+++ b/PDP18B/pdp18b_mt.c
@@ -1,6 +1,6 @@
 /* pdp18b_mt.c: 18b PDP magnetic tape simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -26,6 +26,7 @@
    mt		(PDP-9) TC59 magtape
 		(PDP-15) TC59D magtape
 
+   02-Feb-03	RMS	Revised IOT decoding
    30-Oct-02	RMS	Revised BOT handling, added error record handling
    05-Oct-02	RMS	Added DIB, device number support
 			Revamped error recovery
@@ -192,35 +193,44 @@ DEVICE mt_dev = {
 
 int32 mt (int32 pulse, int32 AC)
 {
-int32 f;
+int32 f, sb;
 UNIT *uptr;
 
 uptr = mt_dev.units + GET_UNIT (mt_cu);			/* get unit */
 mt_updcsta (uptr, 0);					/* update status */
-if (pulse == 001)					/* MTTR */
-	return (!sim_is_active (uptr))? IOT_SKP + AC: AC;
-if (pulse == 021)					/* MTCR */
-	return (!mt_busy ())? IOT_SKP + AC: AC;
-if (pulse == 041)					/* MTSF */
-	return (mt_sta & (STA_ERR | STA_DON))? IOT_SKP + AC: AC;
-if (pulse == 002) return (mt_cu & 0777700);		/* MTRC */
-if (pulse == 042) return mt_sta;			/* MTRS */
-if ((pulse & 062) == 022) {				/* MTAF, MTLC */
-	if (!mt_busy ()) mt_cu = mt_sta = 0;		/* if not busy, clr */
-	mt_sta = mt_sta & ~(STA_ERR | STA_DON);  }	/* clear flags */
-if ((pulse & 064) == 024)				/* MTCM, MTLC  */
-	mt_cu = (mt_cu & 0770700) | (AC & 0777700);	/* load status */
-if (pulse == 004) {					/* MTGO */
-	f = GET_CMD (mt_cu);				/* get function */
-	if (mt_busy () || (sim_is_active (uptr)) ||
-	   (((f == FN_SPACER) || (f == FN_REWIND)) & (uptr->USTAT & STA_BOT)) ||
-	   (((f == FN_WRITE) || (f == FN_WREOF)) && (uptr->flags & UNIT_WPRT))
-	   || ((uptr->flags & UNIT_ATT) == 0) || (f == FN_NOP))
-	    mt_sta = mt_sta | STA_ILL;			/* illegal op flag */
-	else {
-	    if (f == FN_REWIND) uptr->USTAT = STA_REW;	/* rewind? */
-	    else mt_sta = uptr->USTAT = 0;		/* no, clear status */
-	    sim_activate (uptr, mt_time);  }  }		/* start io */
+sb = pulse & 060;					/* subop */
+if (pulse & 01) {
+	if ((sb == 000) && !sim_is_active (uptr))	/* MTTR */
+	    AC = IOT_SKP | AC;
+	else if ((sb == 020) && !mt_busy ())		/* MTCR */
+	    AC = IOT_SKP | AC;
+	else if ((sb == 040) && (mt_sta & (STA_ERR | STA_DON))) /* MTSF */
+	    AC = IOT_SKP | AC;
+	}
+if (pulse & 02) {
+	if (sb == 000) AC = AC | (mt_cu & 0777700);	/* MTRC */
+	else if (sb == 020) {				/* MTAF, MTLC */
+	    if (!mt_busy ()) mt_cu = mt_sta = 0;	/* if not busy, clr */
+	    mt_sta = mt_sta & ~(STA_ERR | STA_DON);  }	/* clear flags */
+	else if (sb == 040) AC = AC | mt_sta;		/* MTRS */
+	}
+if (pulse & 04) {
+	if (sb == 000) {				/* MTGO */
+	    f = GET_CMD (mt_cu);			/* get function */
+	    if (mt_busy () ||
+	        sim_is_active (uptr) ||
+		(f == FN_NOP) ||
+		(((f == FN_SPACER) || (f == FN_REWIND)) && (uptr->USTAT & STA_BOT)) ||
+		(((f == FN_WRITE) || (f == FN_WREOF)) && (uptr->flags & UNIT_WPRT)) ||
+		((uptr->flags & UNIT_ATT) == 0))
+		mt_sta = mt_sta | STA_ILL;		/* illegal op flag */
+	    else {
+		if (f == FN_REWIND) uptr->USTAT = STA_REW;	/* rewind? */
+	        else mt_sta = uptr->USTAT = 0;		/* no, clear status */
+	        sim_activate (uptr, mt_time);  }  }	/* start io */
+	if (sb == 020)					/* MTCM, MTLC  */
+	    mt_cu = (mt_cu & 0770700) | (AC & 0777700);	/* load status */
+	}
 mt_updcsta (mt_dev.units + GET_UNIT (mt_cu), 0);	/* update status */
 return AC;
 }
@@ -340,20 +350,22 @@ case FN_WREOF:
 
 case FN_SPACEF:						/* space forward */
 	do {
+	    M[MT_WC] = (M[MT_WC] + 1) & 0777777;	/* inc WC */
 	    if (mt_rdlntf (uptr, &tbc, &err)) break;	/* read rec lnt, err? */
 	    uptr->pos = uptr->pos + ((tbc + 1) & ~1) +
 		(2 * sizeof (t_mtrlnt));  }
-	while ((M[MT_WC] = (M[MT_WC] + 1) & 0777777) != 0);
+	while (M[MT_WC] != 0);
 	break;
 
 case FN_SPACER:						/* space reverse */
 	do {
+	    M[MT_WC] = (M[MT_WC] + 1) & 0777777;	/* inc WC */
 	    if (pnu) pnu = 0;				/* pos not upd? */
 	    else {
 	    	if (mt_rdlntf (uptr, &tbc, &err)) break;
 		uptr->pos = uptr->pos - ((tbc + 1) & ~1) -
 		    (2 * sizeof (t_mtrlnt));  }  }
-	while ((M[MT_WC] = (M[MT_WC] + 1) & 0777777) != 0);
+	while (M[MT_WC] != 0);
 	break;  }					/* end case */
 
 mt_updcsta (uptr, STA_DON | (err? STA_PAR: 0));		/* set done */
diff --git a/PDP18B/pdp18b_rb.c b/PDP18B/pdp18b_rb.c
new file mode 100644
index 00000000..f25113ab
--- /dev/null
+++ b/PDP18B/pdp18b_rb.c
@@ -0,0 +1,273 @@
+/* pdp18b_rb.c: RB09 fixed head disk simulator
+
+   Copyright (c) 2003, Robert M Supnik
+
+   Permission is hereby granted, free of charge, to any person obtaining a
+   copy of this software and associated documentation files (the "Software"),
+   to deal in the Software without restriction, including without limitation
+   the rights to use, copy, modify, merge, publish, distribute, sublicense,
+   and/or sell copies of the Software, and to permit persons to whom the
+   Software is furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+   ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+   IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+   Except as contained in this notice, the name of Robert M Supnik shall not
+   be used in advertising or otherwise to promote the sale, use or other dealings
+   in this Software without prior written authorization from Robert M Supnik.
+
+   rb		RB09 fixed head disk
+
+   The RB09 is a head-per-track disk.  It uses the single cycle data break
+   facility.  To minimize overhead, the entire RB09 is buffered in memory.
+
+   Two timing parameters are provided:
+
+   rb_time	Interword timing.  Must be non-zero.
+   rb_burst	Burst mode.  If 0, DMA occurs cycle by cycle; otherwise,
+		DMA occurs in a burst.
+*/
+
+#include "pdp18b_defs.h"
+#include <math.h>
+
+/* Constants */
+
+#define RB_NUMWD	64				/* words/sector */
+#define RB_NUMSC	80				/* sectors/track */
+#define RB_NUMTR	200				/* tracks/disk */
+#define RB_WLKTR	10				/* tracks/wlock switch */
+#define RB_SIZE		(RB_NUMTR * RB_NUMSC * RB_NUMWD) /* words/drive */
+
+/* Function/status register */
+
+#define RBS_ERR		0400000				/* error */
+#define RBS_PAR		0200000				/* parity error */
+#define RBS_ILA		0100000				/* ill addr error */
+#define RBS_TIM		0040000				/* timing transfer */
+#define RBS_NRY		0020000				/* not ready error */
+#define RBS_DON		0010000				/* done */
+#define RBS_IE		0004000				/* int enable */
+#define RBS_BSY		0002000				/* busy */
+#define RBS_WR		0001000				/* read/write */
+#define RBS_XOR		(RBS_IE|RBS_BSY|RBS_WR)		/* set by XOR */
+#define RBS_MBZ		0000777				/* always clear */
+#define RBS_EFLGS	(RBS_PAR|RBS_ILA|RBS_TIM|RBS_NRY)	/* error flags */
+
+/* BCD disk address */
+
+#define RBA_V_TR	8
+#define RBA_M_TR	0x1FF
+#define RBA_V_SC	0
+#define RBA_M_SC	0xFF
+#define RBA_GETTR(x)	(((x) >> RBA_V_TR) & RBA_M_TR)
+#define RBA_GETSC(x)	(((x) >> RBA_V_SC) & RBA_M_SC)
+
+#define GET_POS(x)	((int) fmod (sim_gtime () / ((double) (x)), \
+			((double) (RB_NUMSC * RB_NUMWD))))
+
+extern int32 M[];
+extern int32 int_hwre[API_HLVL+1];
+extern UNIT cpu_unit;
+
+int32 rb_sta = 0;					/* status register */
+int32 rb_da = 0;					/* disk address */
+int32 rb_ma = 0;					/* current addr */
+int32 rb_wc = 0;					/* word count */
+int32 rb_wlk = 0;					/* write lock */
+int32 rb_time = 10;					/* inter-word time */
+int32 rb_burst = 1;					/* burst mode flag */
+int32 rb_stopioe = 1;					/* stop on error */
+
+DEVICE rb_dev;
+int32 rb71 (int32 pulse, int32 AC);
+t_stat rb_svc (UNIT *uptr);
+t_stat rb_reset (DEVICE *dptr);
+int32 rb_updsta (int32 new);
+int32 rb_make_da (int32 dat);
+int32 rb_make_bcd (int32 dat);
+int32 rb_set_da (int32 dat, int32 old);
+int32 rb_set_bcd (int32 dat);
+
+/* RB data structures
+
+   rb_dev	RF device descriptor
+   rb_unit	RF unit descriptor
+   rb_reg	RF register list
+*/
+
+DIB rb_dib = { DEV_RB, 1, NULL, { &rb71 } };
+
+UNIT rb_unit =
+	{ UDATA (&rb_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF,
+	RB_SIZE) };
+
+REG rb_reg[] = {
+	{ ORDATA (STA, rb_sta, 18) },
+	{ ORDATA (DA, rb_da, 20) },
+	{ ORDATA (WC, rb_wc, 16) },
+	{ ORDATA (MA, rb_ma, ADDRSIZE) },
+	{ FLDATA (INT, int_hwre[API_RB], INT_V_RB) },
+	{ ORDATA (WLK, rb_wlk, RB_NUMTR / RB_WLKTR) },
+	{ DRDATA (TIME, rb_time, 24), PV_LEFT + REG_NZ },
+	{ FLDATA (BURST, rb_burst, 0) },
+	{ FLDATA (STOP_IOE, rb_stopioe, 0) },
+	{ ORDATA (DEVNO, rb_dib.dev, 6), REG_HRO },
+	{ NULL }  };
+
+MTAB rb_mod[] = {
+	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
+	{ 0 }  };
+
+DEVICE rb_dev = {
+	"RB", &rb_unit, rb_reg, rb_mod,
+	1, 8, 21, 1, 8, 18,
+	NULL, NULL, &rb_reset,
+	NULL, NULL, NULL,
+	&rb_dib, DEV_DIS | DEV_DISABLE };
+
+/* IOT routines */
+
+int32 rb71 (int32 pulse, int32 AC)
+{
+int32 tow, t, sb = pulse & 060;
+
+if (pulse & 001) {
+	if (sb == 000) rb_sta = rb_sta &		/* DBCF */
+	    ~(RBS_ERR | RBS_EFLGS | RBS_DON);
+	if ((sb == 020) && (rb_sta & (RBS_ERR | RBS_DON)))
+	    AC = AC | IOT_SKP;				/* DBSF */
+	if (sb == 040) rb_sta = 0;			/* DBCS */
+	}
+if (pulse & 002) {
+	if (sb == 000) AC = AC | rb_make_da (rb_da);	/* DBRD */
+	if (sb == 020) AC = AC | rb_sta;		/* DBRS */
+	if (sb == 040) rb_ma = AC & ADDRMASK;		/* DBLM */
+	}
+if (pulse & 004) {
+	if (sb == 000) rb_da = rb_set_da (AC, rb_da);	/* DBLD */
+	if (sb == 020) rb_wc = AC & 0177777;		/* DBLW */
+	if (sb == 040) {				/* DBLS */
+	    rb_sta = (rb_sta & RBS_XOR) ^ (AC & ~RBS_MBZ);
+	    if (rb_sta & RBS_BSY) {			/* busy set? */
+		if (!sim_is_active (&rb_unit)) {	/* schedule */
+		    tow = rb_da % (RB_NUMSC * RB_NUMWD);
+		    t = tow - GET_POS (rb_time);
+		    if (t < 0) t = t + (RB_NUMSC * RB_NUMWD);
+		    sim_activate (&rb_unit, t * rb_time);  }  }
+	    else sim_cancel (&rb_unit);  }		/* no, stop */
+	}
+rb_updsta (0);						/* update status */
+return AC;
+}
+
+int32 rb_make_da (int32 da)
+{
+int32 t = da / (RB_NUMSC * RB_NUMWD);			/* bin track */
+int32 s = (da % (RB_NUMSC * RB_NUMWD)) / RB_NUMWD;	/* bin sector */
+int32 bcd_t = rb_make_bcd (t);				/* bcd track */
+int32 bcd_s = rb_make_bcd (s);				/* bcd sector */
+return (bcd_t << RBA_V_TR) | (bcd_s << RBA_V_SC);
+}
+
+int32 rb_set_da (int32 bcda, int32 old_da)
+{
+int32 bcd_t = RBA_GETTR (bcda);				/* bcd track */
+int32 bcd_s = RBA_GETSC (bcda);				/* bcd sector */
+int32 t = rb_set_bcd (bcd_t);				/* bin track */
+int32 s = rb_set_bcd (bcd_s);				/* bin sector */
+
+if ((t >= RB_NUMTR) || (t < 0) ||			/* invalid? */
+    (s >= RB_NUMSC) || (s < 0)) {
+	rb_updsta (RBS_ILA);				/* error */
+	return old_da;  }				/* don't change */
+else return (((t * RB_NUMSC) + s) * RB_NUMWD);		/* new da */
+}
+
+int32 rb_make_bcd (int32 bin)
+{
+int32 d, i, r;
+
+for (r = i = 0; bin != 0; bin = bin / 10) {		/* while nz */
+	d = bin % 10;					/* dec digit */
+	r = r | (d << i);				/* insert bcd */
+	i = i + 4;  }
+return r;
+}
+
+int32 rb_set_bcd (int32 bcd)
+{
+int32 d, i, r;
+
+for (r = 0, i = 1; bcd != 0; bcd = bcd >> 4) {		/* while nz */
+	d = bcd & 0xF;					/* bcd digit */
+	if (d >= 10) return -1;				/* invalid? */
+	r = r + (d * i);				/* insert bin */
+	i = i * 10;  }
+return r;
+}	
+
+/* Unit service - disk is buffered in memory */
+
+t_stat rb_svc (UNIT *uptr)
+{
+int32 t, sw;
+
+if ((uptr->flags & UNIT_BUF) == 0) {			/* not buf? abort */
+	rb_updsta (RBS_NRY | RBS_DON);			/* set nxd, done */
+	return IORETURN (rb_stopioe, SCPE_UNATT);  }
+
+do {	if (rb_sta & RBS_WR) {				/* write? */
+	    t = rb_da / (RB_NUMSC * RB_NUMWD);		/* track */
+	    sw = t / RB_WLKTR;				/* switch */
+	    if ((rb_wlk >> sw) & 1) {			/* write locked? */
+		rb_updsta (RBS_ILA | RBS_DON);
+		break;  }
+	    else {
+	    	*(((int32 *) uptr->filebuf) + rb_da) = M[rb_ma];
+		if (((t_addr) rb_da) >= uptr->hwmark) uptr->hwmark = rb_da + 1;  }  }
+	else if (MEM_ADDR_OK (rb_ma))			/* read, valid addr? */
+	    M[rb_ma] = *(((int32 *) uptr->filebuf) + rb_da);
+	rb_wc = (rb_wc + 1) & 0177777;			/* incr word count */
+ 	rb_ma = (rb_ma + 1) & ADDRMASK;			/* incr mem addr */
+	rb_da = rb_da + 1;				/* incr disk addr */
+	if (rb_da > RB_SIZE) rb_da = 0;			/* disk wraparound? */
+	}
+while ((rb_wc != 0) && (rb_burst != 0));		/* brk if wc, no brst */
+
+if ((rb_wc != 0) && ((rb_sta & RBS_ERR) == 0))		/* more to do? */
+	sim_activate (&rb_unit, rb_time);		/* sched next */
+else rb_updsta (RBS_DON);				/* set done */
+return SCPE_OK;
+}
+
+/* Update status */
+
+int32 rb_updsta (int32 new)
+{
+rb_sta = (rb_sta | new) & ~(RBS_ERR | RBS_MBZ);		/* clear err, mbz */
+if (rb_sta & RBS_EFLGS) rb_sta = rb_sta | RBS_ERR;	/* error? */
+if (rb_sta & RBS_DON) rb_sta = rb_sta & ~RBS_BSY;	/* done? clear busy */
+if ((rb_sta & (RBS_ERR | RBS_DON)) && (rb_sta & RBS_IE))
+	 SET_INT (RB);					/* set or clr intr */
+else CLR_INT (RB);
+return rb_sta;
+}
+
+/* Reset routine */
+
+t_stat rb_reset (DEVICE *dptr)
+{
+rb_sta = rb_da = 0;
+rb_wc = rb_ma = 0;
+rb_updsta (0);
+sim_cancel (&rb_unit);
+return SCPE_OK;
+}
diff --git a/PDP18B/pdp18b_rf.c b/PDP18B/pdp18b_rf.c
index 2d180954..ef1d6be8 100644
--- a/PDP18B/pdp18b_rf.c
+++ b/PDP18B/pdp18b_rf.c
@@ -1,6 +1,6 @@
 /* pdp18b_rf.c: fixed head disk simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -26,6 +26,7 @@
    rf		(PDP-9) RF09/RF09
 		(PDP-15) RF15/RS09
 
+   05-Feb-03	RMS	Fixed decode bugs, added variable and auto sizing
    05-Oct-02	RMS	Added DIB, dev number support
    06-Jan-02	RMS	Revised enable/disable support
    25-Nov-01	RMS	Revised interrupt structure
@@ -48,12 +49,17 @@
 #include "pdp18b_defs.h"
 #include <math.h>
 
+#define UNIT_V_AUTO	(UNIT_V_UF + 0)			/* autosize */
+#define UNIT_V_MSIZE	(UNIT_V_UF + 1)			/* dummy mask */
+#define UNIT_AUTO	(1 << UNIT_V_AUTO)
+#define UNIT_MSIZE	(1 << UNIT_V_MSIZE)
+
 /* Constants */
 
 #define RF_NUMWD	2048				/* words/track */
 #define RF_NUMTR	128				/* tracks/disk */
+#define RF_DKSIZE	(RF_NUMTR * RF_NUMWD)		/* words/disk */
 #define RF_NUMDK	8				/* disks/controller */
-#define RF_SIZE		(RF_NUMDK * RF_NUMTR * RF_NUMWD) /* words/drive */
 #define RF_WMASK	(RF_NUMWD - 1)			/* word mask */
 #define RF_WC		036				/* word count */
 #define RF_CA		037				/* current addr */
@@ -84,7 +90,7 @@
 #define RFS_EFLGS	(RFS_HDW | RFS_APE | RFS_MXF | RFS_WCE | \
 			 RFS_DPE | RFS_WLO | RFS_NED )	/* error flags */
 #define GET_FNC(x)	(((x) >> RFS_V_FNC) & RFS_M_FNC)
-#define GET_POS(x)	((int) fmod (sim_gtime() / ((double) (x)), \
+#define GET_POS(x)	((int) fmod (sim_gtime () / ((double) (x)), \
 			((double) RF_NUMWD)))
 #define RF_BUSY		(sim_is_active (&rf_unit))
 
@@ -107,6 +113,8 @@ int32 rf_iors (void);
 t_stat rf_svc (UNIT *uptr);
 t_stat rf_reset (DEVICE *dptr);
 int32 rf_updsta (int32 new);
+t_stat rf_attach (UNIT *uptr, char *cptr);
+t_stat rf_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
 
 /* RF data structures
 
@@ -118,12 +126,12 @@ int32 rf_updsta (int32 new);
 DIB rf_dib = { DEV_RF, 3, &rf_iors, { &rf70, NULL, &rf72 } };
 
 UNIT rf_unit =
-	{ UDATA (&rf_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF,
-	RF_SIZE) };
+	{ UDATA (&rf_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF+UNIT_AUTO,
+	RF_DKSIZE) };
 
 REG rf_reg[] = {
 	{ ORDATA (STA, rf_sta, 18) },
-	{ ORDATA (DA, rf_da, 21) },
+	{ ORDATA (DA, rf_da, 22) },
 	{ ORDATA (WC, M[RF_WC], 18) },
 	{ ORDATA (CA, M[RF_CA], 18) },
 	{ ORDATA (BUF, rf_dbuf, 18) },
@@ -136,6 +144,15 @@ REG rf_reg[] = {
 	{ NULL }  };
 
 MTAB rf_mod[] = {
+	{ UNIT_MSIZE,  262144, NULL, "1P", &rf_set_size },
+	{ UNIT_MSIZE,  524288, NULL, "2P", &rf_set_size },
+	{ UNIT_MSIZE,  786432, NULL, "3P", &rf_set_size },
+	{ UNIT_MSIZE, 1048576, NULL, "4P", &rf_set_size },
+	{ UNIT_MSIZE, 1310720, NULL, "5P", &rf_set_size },
+	{ UNIT_MSIZE, 1572864, NULL, "6P", &rf_set_size },
+	{ UNIT_MSIZE, 1835008, NULL, "7P", &rf_set_size },
+	{ UNIT_MSIZE, 2097152, NULL, "8P", &rf_set_size },
+	{ UNIT_AUTO, UNIT_AUTO, "autosize", "AUTOSIZE", NULL },
 	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno },
 	{ 0 }  };
 
@@ -143,70 +160,73 @@ DEVICE rf_dev = {
 	"RF", &rf_unit, rf_reg, rf_mod,
 	1, 8, 21, 1, 8, 18,
 	NULL, NULL, &rf_reset,
-	NULL, NULL, NULL,
+	NULL, &rf_attach, NULL,
 	&rf_dib, DEV_DISABLE };
 
 /* IOT routines */
 
 int32 rf70 (int32 pulse, int32 AC)
 {
-int32 t;
+int32 t, sb;
 
-if (pulse == 001)					/* DSSF */
-	return (rf_sta & (RFS_ERR | RFS_DON))? IOT_SKP + AC: AC;
-if (pulse == 021) rf_reset (&rf_dev);			/* DSCC */
-if ((pulse & 061) == 041) {				/* DSCF */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_sta = rf_sta & ~(RFS_FNC | RFS_IE);  }	/* clear func */
-if (pulse == 002)  {					/* DRBR */
+sb = pulse & 060;					/* subopcode */
+if (pulse & 01) {
+	if ((sb == 000)	&& (rf_sta & (RFS_ERR | RFS_DON)))
+	    AC = IOT_SKP | AC;				/* DSSF */
+	else if (sb == 020) rf_reset (&rf_dev);		/* DSCC */
+	else if (sb == 040) {				/* DSCF */
+	    if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;	/* busy inhibits */
+	    else rf_sta = rf_sta & ~(RFS_FNC | RFS_IE);  }	/* clear func */
+	}
+if (pulse & 02) {
 	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy sets PGE */
-	return AC | rf_dbuf;  }
-if (pulse == 022) {					/* DRAL */
+	else if (sb == 000) AC = AC | rf_dbuf;		/* DRBR */
+	else if (sb == 020)				/* DRAL */
+	    AC = AC | (rf_da & 0777777);
+	else if (sb == 040)				/* DSFX */
+	    rf_sta = rf_sta ^ (AC & (RFS_FNC | RFS_IE)); /* xor func */
+	else if (sb == 060)				/* DRAH */
+	    AC = AC | (rf_da >> 18);
+	}
+if (pulse & 04) {
 	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy sets PGE */
-	return rf_da & 0777777;  }
-if (pulse == 062) {					/* DRAH */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy sets PGE */
-	return (rf_da >> 18) | ((rf_sta & RFS_NED)? 010: 0);  }
-if ((pulse & 062) == 042) {				/* DSFX */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_sta = rf_sta ^ (AC & (RFS_FNC | RFS_IE));  } /* xor func */
-if (pulse == 004) {					/* DLBR */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_dbuf = AC;  }
-if (pulse == 024) {					/* DLAL */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_da = (rf_da & ~0777777) | AC;  }
-if (pulse == 064) {					/* DLAH */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_da = (rf_da & 0777777) | ((AC & 07) << 18);  }
-if ((pulse & 064) == 044) {				/* DSCN */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else if (GET_FNC (rf_sta) != FN_NOP) {
-	    t = (rf_da & RF_WMASK) - GET_POS (rf_time);	/* delta to new */
-	    if (t < 0) t = t + RF_NUMWD;		     /* wrap around? */
-	    sim_activate (&rf_unit, t * rf_time);  }  }	/* schedule op */
+	else if (sb == 000) rf_dbuf = AC & 0777777;	/* DLBR */
+	else if (sb == 020)				/* DLAL */
+	    rf_da = (rf_da & ~0777777) | (AC & 0777777);
+	else if (sb == 040) {				/* DSCN */
+	    rf_sta = rf_sta & ~RFS_DON;			/* clear done */
+	    if (GET_FNC (rf_sta) != FN_NOP) {
+		t = (rf_da & RF_WMASK) - GET_POS (rf_time);	/* delta to new */
+		if (t < 0) t = t + RF_NUMWD;			/* wrap around? */
+		sim_activate (&rf_unit, t * rf_time);  }  }	/* schedule op */
+	else if (sb == 060) {				/* DLAH */
+	    rf_da = (rf_da & 0777777) | ((AC & 017) << 18);
+	    if ((t_addr) rf_da >= rf_unit.capac)	/* for sizing */
+		rf_updsta (RFS_NED);  }
+	}
 rf_updsta (0);						/* update status */
 return AC;
 }
 
 int32 rf72 (int32 pulse, int32 AC)
 {
-if (pulse == 002) return AC | GET_POS (rf_time) |	/* DLOK */
-	(sim_is_active (&rf_unit)? 0400000: 0);
-if (pulse == 042) {					/* DSCD */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy inhibits */
-	else rf_sta = 0;
-	rf_updsta (0);  }
-if (pulse == 062) {					/* DSRS */
-	if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;		/* busy sets PGE */
-	return rf_updsta (0);  }
+int32 sb = pulse & 060;
+
+if (pulse & 02) {
+	if (sb == 000) AC = AC | GET_POS (rf_time) |	/* DLOK */
+	    (sim_is_active (&rf_unit)? 0400000: 0);
+	else if (sb == 040) {				/* DSCD */
+	    if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;	/* busy inhibits */
+	    else rf_sta = 0;
+	    rf_updsta (0);  }
+	else if (sb == 060) {				/* DSRS */
+	    if (RF_BUSY) rf_sta = rf_sta | RFS_PGE;	/* busy sets PGE */
+	    AC = AC | rf_updsta (0);  }
+	}
 return AC;
 }
 
-/* Unit service
-
-   This code assumes the entire disk is buffered.
-*/
+/* Unit service - assumes the entire disk is buffered */
 
 t_stat rf_svc (UNIT *uptr)
 {
@@ -217,7 +237,10 @@ if ((uptr->flags & UNIT_BUF) == 0) {			/* not buf? abort */
 	return IORETURN (rf_stopioe, SCPE_UNATT);  }
 
 f = GET_FNC (rf_sta);					/* get function */
-do {	M[RF_WC] = (M[RF_WC] + 1) & 0777777;		/* incr word count */
+do {	if ((t_addr) rf_da >= uptr->capac) {		/* disk overflow? */
+	    rf_updsta (RFS_NED);			/* nx disk error */
+	    break;  }
+	M[RF_WC] = (M[RF_WC] + 1) & 0777777;		/* incr word count */
  	pa = M[RF_CA] = (M[RF_CA] + 1) & ADDRMASK;	/* incr mem addr */
 	if ((f == FN_READ) && MEM_ADDR_OK (pa))		/* read? */
 	    M[pa] = *(((int32 *) uptr->filebuf) + rf_da);
@@ -235,10 +258,7 @@ do {	M[RF_WC] = (M[RF_WC] + 1) & 0777777;		/* incr word count */
 	    	*(((int32 *) uptr->filebuf) + rf_da) = M[pa];
 		if (((t_addr) rf_da) >= uptr->hwmark) uptr->hwmark = rf_da + 1;  }  }
 	rf_da = rf_da + 1;				/* incr disk addr */
-	if (rf_da > RF_SIZE) {				/* disk overflow? */
-	    rf_da = 0;
-	    rf_updsta (RFS_NED);			/* nx disk error */
-	    break;  }  }
+	}
 while ((M[RF_WC] != 0) && (rf_burst != 0));		/* brk if wc, no brst */
 
 if ((M[RF_WC] != 0) && ((rf_sta & RFS_ERR) == 0))	/* more to do? */
@@ -275,3 +295,35 @@ int32 rf_iors (void)
 {
 return ((rf_sta & (RFS_ERR | RFS_DON))? IOS_RF: 0);
 }
+
+/* Attach routine */
+
+t_stat rf_attach (UNIT *uptr, char *cptr)
+{
+int32 p, d;
+int32 ds_bytes = RF_DKSIZE * sizeof (int32);
+
+if (uptr->flags & UNIT_AUTO) {
+	FILE *fp = fopen (cptr, "rb");
+	if (fp == NULL) return SCPE_OPENERR;
+	fseek (fp, 0, SEEK_END);
+	p = ftell (fp);
+	d = (p + ds_bytes - 1) / ds_bytes;
+	if (d == 0) d = 1;
+	if (d > RF_NUMDK) d = RF_NUMDK;
+	uptr->capac = d * RF_DKSIZE;
+	fclose (fp);  }
+return attach_unit (uptr, cptr);
+}
+
+/* Change disk size */
+
+t_stat rf_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
+{
+if ((val == 0) || (val > (RF_NUMDK * RF_DKSIZE)))
+	return SCPE_IERR;
+if (uptr->flags & UNIT_ATT) return SCPE_ALATT;
+uptr->capac = val;
+uptr->flags = uptr->flags & ~UNIT_AUTO;
+return SCPE_OK;
+}
diff --git a/PDP18B/pdp18b_rp.c b/PDP18B/pdp18b_rp.c
index d00fc07a..f8fdd57e 100644
--- a/PDP18B/pdp18b_rp.c
+++ b/PDP18B/pdp18b_rp.c
@@ -1,6 +1,6 @@
 /* pdp18b_rp.c: RP15/RP02 disk pack simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    rp		RP15/RP02 disk pack
 
+   06-Feb-03	RMS	Revised IOT decoding, fixed bug in initiation
    05-Oct-02	RMS	Added DIB, device number support
    06-Jan-02	RMS	Revised enable/disable support
    29-Nov-01	RMS	Added read only unit support
@@ -203,33 +204,41 @@ DEVICE rp_dev = {
 
 int32 rp63 (int32 pulse, int32 AC)
 {
+int32 sb = pulse & 060;					/* subopcode */
+
 rp_updsta (0, 0);
-if (pulse == 001)					/* DPSF */
-	return ((rp_sta & (STA_DON | STA_ERR)) || (rp_stb & STB_ATTN))?
-		IOT_SKP + AC: AC;
-if (pulse == 021)					/* DPSA */
-	return (rp_stb & STB_ATTN)? IOT_SKP + AC: AC;
-if (pulse == 041)					/* DPSJ */
-	return (rp_sta & STA_DON)? IOT_SKP + AC: AC;
-if (pulse == 061)					/* DPSE */
-	return (rp_sta & STA_ERR)? IOT_SKP + AC: AC;
-if (pulse == 002) return rp_sta;			/* DPOSA */
-if (pulse == 022) return rp_stb;			/* DPOSB */
-if (((pulse & 007) == 004) && rp_busy) {		/* busy? */
-	rp_updsta (0, STB_PGE);
-	return AC;  }
-if (pulse == 004) {					/* DPLA */
-	rp_da = AC;
-	if (GET_SECT (rp_da) >= RP_NUMSC) rp_updsta (STA_NXS, 0);
-	if (GET_SURF (rp_da) >= RP_NUMSF) rp_updsta (STA_NXF, 0);
-	if (GET_CYL (rp_da) >= RP_NUMCY) rp_updsta (STA_NXC, 0);  }
-if (pulse == 024) {					/* DPCS */
-	rp_sta = rp_sta & ~(STA_HNF | STA_DON);
-	rp_stb = rp_stb & ~(STB_FME | STB_WPE | STB_LON | STB_WCE |
-	    STB_TME | STB_PGE | STB_EOP);
-	rp_updsta (0, 0);  }
-if (pulse == 044) rp_ma = AC;				/* DPCA */
-if (pulse == 064) rp_wc = AC;				/* DPWC */
+if (pulse & 01) {
+	if ((sb == 000) &&				/* DPSF */
+	    ((rp_sta & (STA_DON | STA_ERR)) || (rp_stb & STB_ATTN)))
+	    AC = IOT_SKP | AC;
+	else if ((sb == 020) && (rp_stb & STB_ATTN))	/* DPSA */
+	    AC = IOT_SKP | AC;
+	else if ((sb == 040) && (rp_sta & STA_DON))	/* DPSJ */
+	    AC = IOT_SKP | AC;
+	else if ((sb == 060) && (rp_sta & STA_ERR))	/* DPSE */
+	    AC = IOT_SKP | AC;
+	}
+if (pulse & 02) {
+	if (sb == 000) AC = AC | rp_sta;		/* DPOSA */
+	else if (sb == 020) AC = AC | rp_stb;		/* DPOSB */
+	}
+if (pulse & 04) {
+	if (rp_busy) {					/* busy? */
+	    rp_updsta (0, STB_PGE);
+	    return AC;  }
+	else if (sb == 000) {				/* DPLA */
+	    rp_da = AC & 0777777;
+	    if (GET_SECT (rp_da) >= RP_NUMSC) rp_updsta (STA_NXS, 0);
+	    if (GET_SURF (rp_da) >= RP_NUMSF) rp_updsta (STA_NXF, 0);
+	    if (GET_CYL (rp_da) >= RP_NUMCY) rp_updsta (STA_NXC, 0);  }
+	else if (sb == 020) {				/* DPCS */
+	    rp_sta = rp_sta & ~(STA_HNF | STA_DON);
+	    rp_stb = rp_stb & ~(STB_FME | STB_WPE | STB_LON | STB_WCE |
+		STB_TME | STB_PGE | STB_EOP);
+	    rp_updsta (0, 0);  }
+	else if (sb == 040) rp_ma = AC & 0777777;	/* DPCA */
+	else if (sb == 060) rp_wc = AC & 0777777;	/* DPWC */
+	}
 return AC;
 }
 
@@ -237,38 +246,45 @@ return AC;
 
 int32 rp64 (int32 pulse, int32 AC)
 {
-int32 u, f, c;
+int32 u, f, c, sb;
 UNIT *uptr;
 
-if (pulse == 021) return IOT_SKP + AC;			/* DPSN */
-if (pulse == 002) return rp_unit[GET_UNIT (rp_sta)].CYL; /* DPOU */
-if (pulse == 022) return rp_da;				/* DPOA */
-if (pulse == 042) return rp_ma;				/* DPOC */
-if (pulse == 062) return rp_wc;				/* DPOW */
-if ((pulse & 007) != 004) return AC;
-if (rp_busy) {						/* busy? */
-	rp_updsta (0, STB_PGE);
-	return AC;  }
-if (pulse == 004) rp_sta = rp_sta & ~STA_RW;		/* DPCF */
-if (pulse == 024) rp_sta = rp_sta & (AC | ~STA_RW);	/* DPLZ */
-if (pulse == 044) rp_sta = rp_sta | (AC & STA_RW);	/* DPLO */
-if (pulse == 064) rp_sta = (rp_sta & ~STA_RW) | (AC & STA_RW); /* DPLF */
-if (rp_sta & STA_GO) {
+sb = pulse & 060;
+if (pulse & 01) {
+	if (sb == 020) AC = IOT_SKP | AC;		/* DPSN */
+	}
+if (pulse & 02) {
+	if (sb == 000) AC = AC | rp_unit[GET_UNIT (rp_sta)].CYL; /* DPOU */
+	else if (sb == 020) AC = AC | rp_da;		/* DPOA */
+	else if (sb == 040) AC = AC | rp_ma;		/* DPOC */
+	else if (sb == 060) AC = AC | rp_wc;		/* DPOW */
+	}
+if (pulse & 04) {
+	if (rp_busy) {					/* busy? */
+	    rp_updsta (0, STB_PGE);
+	    return AC;  }
+	if (sb == 000) rp_sta = rp_sta & ~STA_RW;	/* DPCF */
+	else if (sb == 020) rp_sta = rp_sta & (AC | ~STA_RW);	/* DPLZ */
+	else if (sb == 040) rp_sta = rp_sta | (AC & STA_RW);	/* DPLO */
+	else if (sb == 060)				/* DPLF */
+	    rp_sta = (rp_sta & ~STA_RW) | (AC & STA_RW);
+	rp_sta = rp_sta & ~STA_DON;			/* clear done */
 	u = GET_UNIT (rp_sta);				/* get unit num */
 	uptr = rp_dev.units + u;			/* select unit */
-	if (sim_is_active (uptr)) return AC;		/* can't if busy */
-	f = uptr->FUNC = GET_FUNC (rp_sta);		/* get function */
-	rp_busy = 1;					/* set ctrl busy */
-	rp_sta = rp_sta & ~(STA_HNF | STA_DON);		/* clear flags */
-	rp_stb = rp_stb & ~(STB_FME | STB_WPE | STB_LON | STB_WCE |
-	    STB_TME | STB_PGE | STB_EOP | (1 << (STB_V_ATT0 - u)));
-	if (((uptr->flags & UNIT_ATT) == 0) || (f == FN_IDLE) ||
-	     (f == FN_SEEK) || (f == FN_RECAL))
-	    sim_activate (uptr, RP_MIN);		/* short delay */
-	else {
-	    c = GET_CYL (rp_da);
-	    c = abs (c - uptr->CYL) * rp_swait;		/* seek time */
-	    sim_activate (uptr, MAX (RP_MIN, c + rp_rwait));  }  }
+	if ((rp_sta & STA_GO) && !sim_is_active (uptr)) {
+	    f = uptr->FUNC = GET_FUNC (rp_sta);		/* get function */
+	    rp_busy = 1;				/* set ctrl busy */
+	    rp_sta = rp_sta & ~(STA_HNF | STA_DON);	/* clear flags */
+	    rp_stb = rp_stb & ~(STB_FME | STB_WPE | STB_LON | STB_WCE |
+		STB_TME | STB_PGE | STB_EOP | (1 << (STB_V_ATT0 - u)));
+	    if (((uptr->flags & UNIT_ATT) == 0) || (f == FN_IDLE) ||
+		(f == FN_SEEK) || (f == FN_RECAL))
+		sim_activate (uptr, RP_MIN);		/* short delay */
+	    else {
+		c = GET_CYL (rp_da);
+		c = abs (c - uptr->CYL) * rp_swait;	/* seek time */
+		sim_activate (uptr, MAX (RP_MIN, c + rp_rwait));  }  }
+	}
 rp_updsta (0, 0);
 return AC;
 }
diff --git a/PDP18B/pdp18b_stddev.c b/PDP18B/pdp18b_stddev.c
index 0522181f..6ca61c2f 100644
--- a/PDP18B/pdp18b_stddev.c
+++ b/PDP18B/pdp18b_stddev.c
@@ -433,8 +433,13 @@ if ((temp = getc (ptr_unit.fileref)) == EOF) {		/* end of file? */
 	else perror ("PTR I/O error");
 	clearerr (ptr_unit.fileref);
 	return SCPE_IOERR;  }
-if (ptr_state == 0) ptr_unit.buf = (temp |		/* alpha */
-	((ptr_unit.flags & UNIT_RASCII)? 0200: 0)) & 0377;
+if (ptr_state == 0) {					/* ASCII */
+	if (ptr_unit.flags & UNIT_RASCII) {		/* want parity? */
+	    ptr_unit.buf = temp = temp & 0177;		/* parity off */
+	    while (temp = temp & (temp - 1))
+		ptr_unit.buf = ptr_unit.buf ^ 0200;	/* count bits */
+	    ptr_unit.buf = ptr_unit.buf ^ 0200;  }	/* set even parity */
+	else ptr_unit.buf = temp & 0377;  }
 else if (temp & 0200) {					/* binary */
 	ptr_state = ptr_state - 6;
 	ptr_unit.buf = ptr_unit.buf | ((temp & 077) << ptr_state);  }
diff --git a/PDP18B/pdp18b_sys.c b/PDP18B/pdp18b_sys.c
index d88eba15..70b7b206 100644
--- a/PDP18B/pdp18b_sys.c
+++ b/PDP18B/pdp18b_sys.c
@@ -23,6 +23,7 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   31-Jan-03	RMS	Added support for RB09
    05-Oct-02	RMS	Added variable device number support
    25-Jul-02	RMS	Added PDP-4 DECtape support
    10-Feb-02	RMS	Added PDP-7 DECtape IOT's
@@ -48,11 +49,25 @@ extern DEVICE ptr_dev, ptp_dev;
 extern DEVICE tti_dev, tto_dev;
 extern UNIT tti_unit, tto_unit;
 extern DEVICE clk_dev;
-extern DEVICE lpt_dev;
+#if defined (TYPE62)
+extern DEVICE lp62_dev;
+#endif
+#if defined (TYPE647)
+extern DEVICE lp647_dev;
+#endif
+#if defined (LP09)
+extern DEVICE lp09_dev;
+#endif
+#if defined (LP15)
+extern DEVICE lp15_dev;
+#endif
 extern DEVICE dt_dev;
 #if defined (DRM)
 extern DEVICE drm_dev;
 #endif
+#if defined (RB)
+extern DEVICE rb_dev;
+#endif
 #if defined (RF)
 extern DEVICE rf_dev;
 #endif
@@ -97,12 +112,29 @@ REG *sim_PC = &cpu_reg[0];
 int32 sim_emax = 3;
 
 DEVICE *sim_devices[] = { &cpu_dev,
-	&ptr_dev, &ptp_dev,
-	&tti_dev, &tto_dev,
-	&clk_dev, &lpt_dev,
+	&ptr_dev,
+	&ptp_dev,
+	&tti_dev,
+	&tto_dev,
+	&clk_dev,
+#if defined (TYPE62)
+	&lp62_dev,
+#endif
+#if defined (TYPE647)
+	&lp647_dev,
+#endif
+#if defined (LP09)
+	&lp09_dev,
+#endif
+#if defined (LP15)
+	&lp15_dev,
+#endif
 #if defined (DRM)
 	&drm_dev,
 #endif
+#if defined (RB)
+	&rb_dev,
+#endif
 #if defined (RF)
 	&rf_dev,
 #endif
@@ -321,15 +353,21 @@ static const char *opcode[] = {
  "PSF", "PCF", "PSA", "PSB", "PLS",
  "KSF", "KRB", "KCF", "IORS", "IOOS",
  "TSF", "TCF", "TPC", "TLS",
-#if defined (TYPE62)					/* PDP-4 LPT */
+#if defined (TYPE62)					/* Type 62 */
  "LPSF", "LPCF", "LPLD", "LPSE",
  "LSSF", "LSCF", "LSPR",
-#elif defined (TYPE647)					/* PDP-7, PDP-9 LPT */
+#endif
+#if defined (TYPE647)					/* Type 647 */
  "LPSF", "LPCB", "LPCD", "LPCD", "LPCD",
  "LPL2", "LPLD", "LPL1",
  "LPEF", "LPCF", "LPCF", "LPCF", "LPCF",
  "LPPB", "LPLS", "LPPS",
-#elif defined (LP15)					/* PDP-15 LPT */
+#endif
+#if defined (LP09)
+ "LSDF", "LSEF", "LSCF", "LPLD",
+ "LIOF", "LION",
+#endif
+#if defined (LP15)					/* LP15 */
  "LPSF", "LPPM", "LPP1", "LPDI",
  "LPRS", "LPOS", "LPEI", "LPCD", "LPCF",
 #endif
@@ -339,6 +377,11 @@ static const char *opcode[] = {
  "DRLCRD", "DRLCWR", "DRLBLK", "DRCONT",
  "DRSF", "DRSOK", "DRCF",
 #endif
+#if defined (RB)					/* RB09 */
+ "DBCF", "DBRD", "DBLD",
+ "DBSF", "DBRS", "DBLW",
+ "DBCS", "DBLM", "DBLS",
+#endif
 #if defined (RF)					/* RF09 */
  "DSSF", "DSCC", "DSCF",
  "DRBR", "DRAL", "DSFX", "DRAH",
@@ -478,12 +521,18 @@ static const int32 opc_val[] = {
 #if defined (TYPE62)
  0706501+I_NPI, 0706502+I_NPI, 0706542+I_NPI, 0706506+I_NPI,
  0706601+I_NPI, 0706602+I_NPI, 0706606+I_NPI,
-#elif defined (TYPE647)
+#endif
+#if defined (TYPE647)
  0706501+I_NPI, 0706502+I_NPI, 0706522+I_NPI, 0706542+I_NPI, 0706562+I_NPI,
  0706526+I_NPI, 0706546+I_NPI, 0706566+I_NPI,
  0706601+I_NPI, 0706602+I_NPI, 0706622+I_NPI, 0706642+I_NPI, 0706662+I_NPI, 
  0706606+I_NPI, 0706626+I_NPI, 0706646+I_NPI,
-#elif defined (LP15)
+#endif
+#if defined (LP09)
+ 0706601+I_NPI, 0706621+I_NPI, 0706602+I_NPI, 0706622+I_NPI,
+ 0706604+I_NPI, 0706644+I_NPI,
+#endif
+#if defined (LP15)
  0706501+I_NPI, 0706521+I_NPI, 0706541+I_NPI, 0706561+I_NPI,
  0706552+I_NPN, 0706542+I_NPI, 0706544+I_NPI, 0706621+I_NPI, 0706641+I_NPI,
 #endif
@@ -493,6 +542,11 @@ static const int32 opc_val[] = {
  0706006+I_NPI, 0706046+I_NPI, 0706106+I_NPI, 0706204+I_NPI,
  0706101+I_NPI, 0706201+I_NPI, 0706102+I_NPI,
 #endif
+#if defined (RB)
+ 0707101+I_NPI, 0707112+I_NPN, 0707104+I_NPI,
+ 0707121+I_NPI, 0707132+I_NPN, 0707124+I_NPI,
+ 0707141+I_NPI, 0707142+I_NPI, 0707144+I_NPI,
+#endif
 #if defined (RF)
  0707001+I_NPI, 0707021+I_NPI, 0707041+I_NPI,
  0707002+I_NPI, 0707022+I_NPI, 0707042+I_NPI, 0707062+I_NPI,
diff --git a/PDP8/pdp8_df.c b/PDP8/pdp8_df.c
index 3165a717..589c4732 100644
--- a/PDP8/pdp8_df.c
+++ b/PDP8/pdp8_df.c
@@ -1,6 +1,6 @@
 /* pdp8_df.c: DF32 fixed head disk simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    df		DF32 fixed head disk
 
+   02-Feb-03	RMS	Added variable platter and autosizing support
    04-Oct-02	RMS	Added DIBs, device number support
    28-Nov-01	RMS	Added RL8A support
    25-Apr-01	RMS	Added device enable/disable support
@@ -42,12 +43,17 @@
 #include "pdp8_defs.h"
 #include <math.h>
 
+#define UNIT_V_AUTO	(UNIT_V_UF + 0)			/* autosize */
+#define UNIT_V_MSIZE	(UNIT_V_UF + 1)			/* dummy mask */
+#define UNIT_AUTO	(1 << UNIT_V_AUTO)
+#define UNIT_MSIZE	(1 << UNIT_V_MSIZE)
+
 /* Constants */
 
 #define DF_NUMWD	2048				/* words/track */
 #define DF_NUMTR	16				/* tracks/disk */
+#define DF_DKSIZE	(DF_NUMTR * DF_NUMWD)		/* words/disk */
 #define DF_NUMDK	4				/* disks/controller */
-#define DF_SIZE		(DF_NUMDK * DF_NUMTR * DF_NUMWD) /* words/drive */
 #define DF_WC		07750				/* word count */
 #define DF_MA		07751				/* mem address */
 #define DF_WMASK	(DF_NUMWD - 1)			/* word mask */
@@ -65,8 +71,9 @@
 #define DFS_MEX		00070				/* mem addr extension */
 #define DFS_DRL		00004				/* data late error */
 #define DFS_WLS		00002				/* write lock error */
+#define DFS_NXD		00002				/* non-existent disk */
 #define DFS_PER		00001				/* parity error */
-#define DFS_ERR		(DFS_DRL + DFS_WLS + DFS_PER)
+#define DFS_ERR		(DFS_DRL | DFS_WLS | DFS_PER)
 #define DFS_V_DEX	6
 #define DFS_V_MEX	3
 
@@ -97,6 +104,8 @@ t_stat df_svc (UNIT *uptr);
 t_stat pcell_svc (UNIT *uptr);
 t_stat df_reset (DEVICE *dptr);
 t_stat df_boot (int32 unitno, DEVICE *dptr);
+t_stat df_attach (UNIT *uptr, char *cptr);
+t_stat df_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
 
 /* DF32 data structures
 
@@ -110,7 +119,7 @@ DIB df_dib = { DEV_DF, 3, { &df60, &df61, &df62 } };
 
 UNIT df_unit =
 	{ UDATA (&df_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF,
-	DF_SIZE) };
+	DF_NUMDK * DF_DKSIZE) };
 
 REG df_reg[] = {
 	{ ORDATA (STA, df_sta, 12) },
@@ -127,6 +136,10 @@ REG df_reg[] = {
 	{ NULL }  };
 
 MTAB df_mod[] = {
+	{ UNIT_MSIZE,  32768, NULL, "1P", &df_set_size },
+	{ UNIT_MSIZE,  65536, NULL, "2P", &df_set_size },
+	{ UNIT_MSIZE,  98304, NULL, "3P", &df_set_size },
+	{ UNIT_MSIZE, 131072, NULL, "4P", &df_set_size },
 	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO",
 		&set_dev, &show_dev, NULL },
 	{ 0 } };
@@ -135,7 +148,7 @@ DEVICE df_dev = {
 	"DF", &df_unit, df_reg, df_mod,
 	1, 8, 17, 1, 8, 12,
 	NULL, NULL, &df_reset,
-	&df_boot, NULL, NULL,
+	&df_boot, &df_attach, NULL,
 	&df_dib, DEV_DISABLE };
 
 /* IOT routines */
@@ -220,7 +233,10 @@ if ((uptr->flags & UNIT_BUF) == 0) {			/* not buf? abort */
 
 mex = GET_MEX (df_sta);
 da = GET_DEX (df_sta) | df_da;				/* form disk addr */
-do {	M[DF_WC] = (M[DF_WC] + 1) & 07777;		/* incr word count */
+do {	if (da >= uptr->capac) {			/* nx disk addr? */
+	    df_sta = df_sta | DFS_NXD;
+	    break;  }
+	M[DF_WC] = (M[DF_WC] + 1) & 07777;		/* incr word count */
  	M[DF_MA] = (M[DF_MA] + 1) & 07777;		/* incr mem addr */
 	pa = mex | M[DF_MA]; 				/* add extension */
 	if (uptr->FUNC == DF_READ) {			/* read? */
@@ -235,7 +251,7 @@ do {	M[DF_WC] = (M[DF_WC] + 1) & 07777;		/* incr word count */
 	da = (da + 1) & 0377777;  }			/* incr disk addr */
 while ((M[DF_WC] != 0) && (df_burst != 0));		/* brk if wc, no brst */
 
-if (M[DF_WC] != 0)					/* more to do? */
+if ((M[DF_WC] != 0) && ((df_sta & DFS_ERR) == 0))	/* more to do? */
 	sim_activate (&df_unit, df_time);		/* sched next */
 else {	if (uptr->FUNC != DF_READ) da = (da - 1) & 0377777;
 	df_done = 1;					/* done */
@@ -295,3 +311,34 @@ else {	for (i = 0; i < OS8_LEN; i++)
 	saved_PC = OS8_START;  }
 return SCPE_OK;
 }
+
+
+t_stat df_attach (UNIT *uptr, char *cptr)
+{
+int32 p, d;
+int32 ds_bytes = DF_DKSIZE * sizeof (int16);
+
+if (uptr->flags & UNIT_AUTO) {
+	FILE *fp = fopen (cptr, "rb");
+	if (fp == NULL) return SCPE_OPENERR;
+	fseek (fp, 0, SEEK_END);
+	p = ftell (fp);
+	d = (p + ds_bytes - 1) / ds_bytes;
+	if (d == 0) d = 1;
+	if (d > DF_NUMDK) d = DF_NUMDK;
+	uptr->capac = d * DF_DKSIZE;
+	fclose (fp);  }
+return attach_unit (uptr, cptr);
+}
+
+/* Change disk size */
+
+t_stat df_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
+{
+if ((val == 0) || (val > (DF_NUMDK * DF_DKSIZE)))
+	return SCPE_IERR;
+if (uptr->flags & UNIT_ATT) return SCPE_ALATT;
+uptr->capac = val;
+uptr->flags = uptr->flags & ~UNIT_AUTO;
+return SCPE_OK;
+}
diff --git a/PDP8/pdp8_doc.txt b/PDP8/pdp8_doc.txt
index aef8c49f..b4ca45cb 100644
--- a/PDP8/pdp8_doc.txt
+++ b/PDP8/pdp8_doc.txt
@@ -1,14 +1,14 @@
 To:	Users
 From:	Bob Supnik
 Subj:	PDP-8 Simulator Usage
-Date:	15-Nov-2002
+Date:	1-Feb-2003
 
 			COPYRIGHT NOTICE
 
 The following copyright notice applies to both the SIMH source and binary:
 
-   Original code published in 1993-2002, written by Robert M Supnik
-   Copyright (c) 1993-2002, Robert M Supnik
+   Original code published in 1993-2003, written by Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -76,8 +76,8 @@ TTIX,TTOX	KL8JA additional terminals
 LPT		LE8E line printer
 CLK		DK8E line frequency clock (also PDP-8/A compatible)
 RK		RK8E/RK05 cartridge disk controller with four drives
-RF		RF08/RS08 fixed head disk controller with four platters, or
-DF		DF32/DS32 fixed head disk controller with four platters
+RF		RF08/RS08 fixed head disk controller with 1-4 platters, or
+DF		DF32/DS32 fixed head disk controller with 1-4 platters
 RL		RL8A/RL01 cartridge disk controller with four drives
 RX		RX8E/RX01, RX28/RX02 floppy disk controller with two drives
 DT		TC08/TU56 DECtape controller with eight drives
@@ -506,6 +506,18 @@ not both, with default device addressing.
 
 2.5.1 RF08/RS08 Fixed Head Disk (RF)
 
+RF08 options include the ability to set the number of platters to a
+fixed value between 1 and 4, or to autosize the number of platters
+from the attached file:
+
+	SET RF 1P		one platter (256K)
+	SET RF 2P		two platters (512K)
+	SET RF 3P		three platters (768K)
+	SET RF 4P		four platters (1024K)
+	SET RF AUTOSIZE		autosized on attach
+
+The default is four platters.
+
 The RF08 implements these registers:
 
 	name		size	comments
@@ -540,6 +552,18 @@ I/O errors cannot occur.
 
 2.5.2 DF32/DS32 Fixed Head Disk (RF)
 
+DF32 options include the ability to set the number of platters to a
+fixed value between 1 and 4, or to autosize the number of platters
+from the attached file:
+
+	SET DF 1P		one platter (32K)
+	SET DF 2P		two platters (64K)
+	SET DF 3P		three platters (98K)
+	SET DF 4P		four platters (128K)
+	SET DF AUTOSIZE		autosized on attach
+
+The default is four platters.
+
 The DF32 implements these registers:
 
 	name		size	comments
diff --git a/PDP8/pdp8_rf.c b/PDP8/pdp8_rf.c
index f38badfb..fa3f0728 100644
--- a/PDP8/pdp8_rf.c
+++ b/PDP8/pdp8_rf.c
@@ -1,6 +1,6 @@
 /* pdp8_rf.c: RF08 fixed head disk simulator
 
-   Copyright (c) 1993-2002, Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -25,6 +25,7 @@
 
    rf		RF08 fixed head disk
 
+   02-Feb-03	RMS	Added variable platter and autosizing support
    04-Oct-02	RMS	Added DIB, device number support
    28-Nov-01	RMS	Added RL8A support
    25-Apr-01	RMS	Added device enable/disable support
@@ -46,12 +47,17 @@
 #include "pdp8_defs.h"
 #include <math.h>
 
+#define UNIT_V_AUTO	(UNIT_V_UF + 0)			/* autosize */
+#define UNIT_V_MSIZE	(UNIT_V_UF + 1)			/* dummy mask */
+#define UNIT_AUTO	(1 << UNIT_V_AUTO)
+#define UNIT_MSIZE	(1 << UNIT_V_MSIZE)
+
 /* Constants */
 
 #define RF_NUMWD	2048				/* words/track */
 #define RF_NUMTR	128				/* tracks/disk */
+#define RF_DKSIZE	(RF_NUMTR * RF_NUMWD)		/* words/disk */
 #define RF_NUMDK	4				/* disks/controller */
-#define RF_SIZE		(RF_NUMDK * RF_NUMTR * RF_NUMWD) /* words/drive */
 #define RF_WC		07750				/* word count */
 #define RF_MA		07751				/* mem address */
 #define RF_WMASK	(RF_NUMWD - 1)			/* word mask */
@@ -109,6 +115,8 @@ t_stat rf_svc (UNIT *uptr);
 t_stat pcell_svc (UNIT *uptr);
 t_stat rf_reset (DEVICE *dptr);
 t_stat rf_boot (int32 unitno, DEVICE *dptr);
+t_stat rf_attach (UNIT *uptr, char *cptr);
+t_stat rf_set_size (UNIT *uptr, int32 val, char *cptr, void *desc);
 
 /* RF08 data structures
 
@@ -122,7 +130,7 @@ DIB rf_dib = { DEV_RF, 5, { &rf60, &rf61, &rf62, NULL, &rf64 } };
 
 UNIT rf_unit =
 	{ UDATA (&rf_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_BUFABLE+UNIT_MUSTBUF,
-	RF_SIZE) };
+	RF_NUMDK * RF_DKSIZE) };
 
 UNIT pcell_unit = { UDATA (&pcell_svc, 0, 0) };
 
@@ -141,6 +149,11 @@ REG rf_reg[] = {
 	{ NULL }  };
 
 MTAB rf_mod[] = {
+	{ UNIT_MSIZE,  262144, NULL, "1P", &rf_set_size },
+	{ UNIT_MSIZE,  524288, NULL, "2P", &rf_set_size },
+	{ UNIT_MSIZE,  786432, NULL, "3P", &rf_set_size },
+	{ UNIT_MSIZE, 1048576, NULL, "4P", &rf_set_size },
+	{ UNIT_AUTO, UNIT_AUTO, "autosize", "AUTOSIZE", NULL },
 	{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO",
 		&set_dev, &show_dev, NULL },
 	{ 0 } };
@@ -149,7 +162,7 @@ DEVICE rf_dev = {
 	"RF", &rf_unit, rf_reg, rf_mod,
 	1, 8, 20, 1, 8, 12,
 	NULL, NULL, &rf_reset,
-	&rf_boot, NULL, NULL,
+	&rf_boot, &rf_attach, NULL,
 	&rf_dib, DEV_DISABLE | DEV_DIS };
 
 /* IOT routines */
@@ -187,7 +200,7 @@ case 1:							/* DCIM */
 	sim_cancel (&pcell_unit);			/* cancel photocell */
 	return AC;
 case 2:							/* DSAC */
-	return ((rf_da & RF_WMASK) == GET_POS (rf_time))? IOT_SKP + AC: AC;
+	return ((rf_da & RF_WMASK) == GET_POS (rf_time))? IOT_SKP: 0;
 case 5:							/* DIML */
 	rf_sta = (rf_sta & 07007) | (AC & 0770);	/* STA<3:8> <- AC */
 	if (rf_sta & RFS_PIE)				/* photocell int? */
@@ -225,14 +238,25 @@ UPDATE_PCELL;						/* update photocell */
 switch (pulse) {					/* decode IR<9:11> */
 case 1:							/* DCXA */
 	rf_da = rf_da & 07777;				/* clear DAR<0:7> */
-	return AC;
+	break;
 case 3:							/* DXAL */
-	rf_da = (rf_da & 07777) | ((AC & 0377) << 12);	/* DAR<0:7> <- AC */
-	return 0;					/* clear AC */
+	rf_da = rf_da & 07777;				/* clear DAR<0:7> */
+case 2:							/* DXAL w/o clear */
+	rf_da = rf_da | ((AC & 0377) << 12);		/* DAR<0:7> |= AC */
+	AC = AC & ~07777;				/* clear AC */
+	break;
 case 5:							/* DXAC */
-	return ((rf_da >> 12) & 0377);			/* AC <- DAR<0:7> */
+	AC = AC & ~07777;				/* clear AC */
+case 4:							/* DXAC w/o clear */
+	AC = AC | ((rf_da >> 12) & 0377);		/* AC |= DAR<0:7> */
+	break;
 default:
-	return (stop_inst << IOT_V_REASON) + AC;  }	/* end switch */
+	AC = (stop_inst << IOT_V_REASON) + AC;
+	break;  }					/* end switch */
+if ((t_addr) rf_da >= rf_unit.capac) rf_sta = rf_sta | RFS_NXD;
+else rf_sta = rf_sta & ~RFS_NXD;
+RF_INT_UPDATE;
+return AC;
 }
 
 /* Unit service
@@ -253,7 +277,10 @@ if ((uptr->flags & UNIT_BUF) == 0) {			/* not buf? abort */
 	return IORETURN (rf_stopioe, SCPE_UNATT);  }
 
 mex = GET_MEX (rf_sta);
-do {	M[RF_WC] = (M[RF_WC] + 1) & 07777;		/* incr word count */
+do {	if ((t_addr) rf_da >= rf_unit.capac) {		/* disk overflow? */
+	    rf_sta = rf_sta | RFS_NXD;
+	    break;  }
+	M[RF_WC] = (M[RF_WC] + 1) & 07777;		/* incr word count */
  	M[RF_MA] = (M[RF_MA] + 1) & 07777;		/* incr mem addr */
 	pa = mex | M[RF_MA]; 				/* add extension */
 	if (uptr->FUNC == RF_READ) {			/* read? */
@@ -268,7 +295,7 @@ do {	M[RF_WC] = (M[RF_WC] + 1) & 07777;		/* incr word count */
 	rf_da = (rf_da + 1) & 03777777;  }		/* incr disk addr */
 while ((M[RF_WC] != 0) && (rf_burst != 0));		/* brk if wc, no brst */
 
-if (M[RF_WC] != 0)					/* more to do? */
+if ((M[RF_WC] != 0) && ((rf_sta	& RFS_ERR) == 0))	/* more to do? */
 	sim_activate (&rf_unit, rf_time);		/* sched next */
 else {	rf_done = 1;					/* done */
 	RF_INT_UPDATE;  }				/* update int req */
@@ -338,3 +365,35 @@ else {	for (i = 0; i < OS8_LEN; i++)
 	saved_PC = OS8_START;  }
 return SCPE_OK;
 }
+
+/* Attach routine */
+
+t_stat rf_attach (UNIT *uptr, char *cptr)
+{
+int32 p, d;
+int32 ds_bytes = RF_DKSIZE * sizeof (int16);
+
+if (uptr->flags & UNIT_AUTO) {
+	FILE *fp = fopen (cptr, "rb");
+	if (fp == NULL) return SCPE_OPENERR;
+	fseek (fp, 0, SEEK_END);
+	p = ftell (fp);
+	d = (p + ds_bytes - 1) / ds_bytes;
+	if (d == 0) d = 1;
+	if (d > RF_NUMDK) d = RF_NUMDK;
+	uptr->capac = d * RF_DKSIZE;
+	fclose (fp);  }
+return attach_unit (uptr, cptr);
+}
+
+/* Change disk size */
+
+t_stat rf_set_size (UNIT *uptr, int32 val, char *cptr, void *desc)
+{
+if ((val == 0) || (val > (RF_NUMDK * RF_DKSIZE)))
+	return SCPE_IERR;
+if (uptr->flags & UNIT_ATT) return SCPE_ALATT;
+uptr->capac = val;
+uptr->flags = uptr->flags & ~UNIT_AUTO;
+return SCPE_OK;
+}
diff --git a/descrip.mms b/descrip.mms
index 0b505ec8..cb92b758 100644
--- a/descrip.mms
+++ b/descrip.mms
@@ -205,7 +205,7 @@ HP2100_OBJS = $(HP2100_DIR)HP2100_STDDEV.OBJ,$(HP2100_DIR)HP2100_DP.OBJ,\
               $(HP2100_DIR)HP2100_LPS.OBJ,$(HP2100_DIR)HP2100_MS.OBJ,\
               $(HP2100_DIR)HP2100_MT.OBJ,$(HP2100_DIR)HP2100_MUX.OBJ,\
               $(HP2100_DIR)HP2100_CPU.OBJ,$(HP2100_DIR)HP2100_FP.OBJ,\
-              $(HP2100_DIR)HP2100_SYS.OBJ,$(HP2100_DIR)HP2100_LPT.OBJ,
+              $(HP2100_DIR)HP2100_SYS.OBJ,$(HP2100_DIR)HP2100_LPT.OBJ,\
               $(HP2100_DIR)HP2100_IPL.OBJ
 HP2100_OPTIONS = /INCLUDE=($(SIMH_DIR),$(HP2100_DIR))
 
@@ -336,12 +336,14 @@ PDP18B_SOURCE = $(PDP18B_DIR)PDP18B_DT.C,$(PDP18B_DIR)PDP18B_DRM.C,\
                 $(PDP18B_DIR)PDP18B_CPU.C,$(PDP18B_DIR)PDP18B_LP.C,\
                 $(PDP18B_DIR)PDP18B_MT.C,$(PDP18B_DIR)PDP18B_RF.C,\
                 $(PDP18B_DIR)PDP18B_RP.C,$(PDP18B_DIR)PDP18B_STDDEV.C,\
-                $(PDP18B_DIR)PDP18B_SYS.C,$(PDP18B_DIR)PDP18B_TT1.C
+                $(PDP18B_DIR)PDP18B_SYS.C,$(PDP18B_DIR)PDP18B_TT1.C,\
+                $(PDP18B_DIR)PDP18B_RB.C
 PDP18B_OBJS = $(PDP18B_DIR)PDP18B_DT.OBJ,$(PDP18B_DIR)PDP18B_DRM.OBJ,\
               $(PDP18B_DIR)PDP18B_CPU.OBJ,$(PDP18B_DIR)PDP18B_LP.OBJ,\
               $(PDP18B_DIR)PDP18B_MT.OBJ,$(PDP18B_DIR)PDP18B_RF.OBJ,\
               $(PDP18B_DIR)PDP18B_RP.OBJ,$(PDP18B_DIR)PDP18B_STDDEV.OBJ,\
-              $(PDP18B_DIR)PDP18B_SYS.OBJ,$(PDP18B_DIR)PDP18B_TT1.OBJ
+              $(PDP18B_DIR)PDP18B_SYS.OBJ,$(PDP18B_DIR)PDP18B_TT1.OBJ,\
+              $(PDP18B_DIR)PDP18B_RB.OBJ
 PDP4_OPTIONS = /INCLUDE=($(SIMH_DIR),$(PDP18B_DIR))/DEFINE=("PDP4=1")
 PDP7_OPTIONS = /INCLUDE=($(SIMH_DIR),$(PDP18B_DIR))/DEFINE=("PDP7=1")
 PDP9_OPTIONS = /INCLUDE=($(SIMH_DIR),$(PDP18B_DIR))/DEFINE=("PDP9=1")
@@ -374,7 +376,7 @@ PDP11_OBJS = $(PDP11_DIR)PDP11_FP.OBJ,$(PDP11_DIR)PDP11_CPU.OBJ,\
              $(PDP11_DIR)PDP11_IO.OBJ,$(PDP11_DIR)PDP11_RQ.OBJ,\
              $(PDP11_DIR)PDP11_TQ.OBJ,$(PDP11_DIR)PDP11_PCLK.OBJ,\
              $(PDP11_DIR)PDP11_RY.OBJ,$(PDP11_DIR)PDP11_PT.OBJ,\
-             $(PDP11_DIR)PDP11_HK.OBJ,$(PDP11_DIR)PDP11_XQ.OBJ,
+             $(PDP11_DIR)PDP11_HK.OBJ,$(PDP11_DIR)PDP11_XQ.OBJ,\
              $(PDP11_DIR)PDP11_XU.OBJ
 PDP11_OPTIONS = /INCLUDE=($(SIMH_DIR),$(PDP11_DIR))
 
diff --git a/makefile b/makefile
index 380c20ee..388a9aed 100644
--- a/makefile
+++ b/makefile
@@ -61,7 +61,7 @@ PDP18BD = PDP18B/
 PDP18B = ${PDP18BD}pdp18b_dt.c ${PDP18BD}pdp18b_drm.c ${PDP18BD}pdp18b_cpu.c \
 	${PDP18BD}pdp18b_lp.c ${PDP18BD}pdp18b_mt.c ${PDP18BD}pdp18b_rf.c \
 	${PDP18BD}pdp18b_rp.c ${PDP18BD}pdp18b_stddev.c ${PDP18BD}pdp18b_sys.c \
-	${PDP18BD}pdp18b_tt1.c
+	${PDP18BD}pdp18b_rb.c ${PDP18BD}pdp18b_tt1.c
 PDP4_OPT = -DPDP4 -I ${PDP18BD}
 PDP7_OPT = -DPDP7 -I ${PDP18BD}
 PDP9_OPT = -DPDP9 -I ${PDP18BD}
diff --git a/scp.c b/scp.c
index 35dba2de..9a2da767 100644
--- a/scp.c
+++ b/scp.c
@@ -23,6 +23,8 @@
    be used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
+   07-Feb-03	RMS	Added VMS support for ! (from Mark Pizzolato)
+   01-Feb-03	RMS	Added breakpoint table extension, actions
    14-Jan-03	RMS	Added missing function prototypes
    10-Jan-03	RMS	Added attach/restore flag, dynamic memory size support,
 			case sensitive SET options
@@ -130,7 +132,7 @@
 #define RU_BOOT		4				/* boot */
 
 #define SRBSIZ		1024				/* save/restore buffer */
-#define SIM_BRK_INILNT	16384				/* bpt tbl length */
+#define SIM_BRK_INILNT	4096				/* bpt tbl length */
 #define SIM_BRK_ALLTYP	0xFFFFFFFF
 #define SIM_NTIMERS	8				/* # timers */
 #define SIM_TMAX	500				/* max timer makeup */
@@ -227,7 +229,7 @@ extern uint32 sim_os_msec (void);
 /* Prototypes */
 
 t_stat sim_brk_init (void);
-t_stat sim_brk_set (t_addr loc, int32 sw, int32 ncnt);
+t_stat sim_brk_set (t_addr loc, int32 sw, int32 ncnt, char *act);
 t_stat sim_brk_clr (t_addr loc, int32 sw);
 t_stat sim_brk_clrall (int32 sw);
 t_stat sim_brk_show (FILE *st, t_addr loc, int32 sw);
@@ -318,6 +320,7 @@ int32 sim_is_running = 0;
 uint32 sim_brk_summ = 0;
 uint32 sim_brk_types = 0;
 uint32 sim_brk_dflt = 0;
+char *sim_brk_act = NULL;
 BRKTAB *sim_brk_tab = NULL;
 int32 sim_brk_ent = 0;
 int32 sim_brk_lnt = 0;
@@ -567,12 +570,15 @@ else stat = SCPE_OK;
 
 while (stat != SCPE_EXIT) {				/* in case exit */
 	printf ("sim> ");				/* prompt */
-	if (sim_vm_read != NULL)			/* sim routine? */
+	if (cptr = sim_brk_act) {			/* pending action? */
+	    printf ("%s\n", sim_brk_act);
+	    sim_brk_act = NULL;  }
+	else if (sim_vm_read != NULL)			/* sim routine? */
 	    cptr = (*sim_vm_read) (cbuf, CBUFSIZE, stdin);
 	else cptr = read_line (cbuf, CBUFSIZE, stdin);	/* read command line */
 	if (cptr == NULL) continue;			/* ignore EOF */
 	if (*cptr == 0) continue;			/* ignore blank */
-	if (sim_log) fprintf (sim_log, "sim> %s\n", cbuf); /* log cmd */
+	if (sim_log) fprintf (sim_log, "sim> %s\n", cptr); /* log cmd */
 	cptr = get_glyph (cptr, gbuf, 0);		/* get command glyph */
 	if (cmdp = find_cmd (gbuf))			/* lookup command */
 	    stat = cmdp->action (cmdp->arg, cptr);	/* if found, exec */
@@ -643,9 +649,16 @@ return SCPE_OK;
 
 t_stat spawn_cmd (int32 flag, char *cptr)
 {
-if ((cptr == NULL) || (strlen(cptr) == 0)) cptr = getenv("SHELL");
-if ((cptr == NULL) || (strlen(cptr) == 0)) cptr = getenv("ComSpec");
+if ((cptr == NULL) || (strlen (cptr) == 0)) cptr = getenv("SHELL");
+if ((cptr == NULL) || (strlen (cptr) == 0)) cptr = getenv("ComSpec");
+#if defined (VMS)
+if ((cptr == NULL) || (strlen (cptr) == 0)) cptr = "SPAWN/INPUT=SYS$COMMAND:";
+#endif
 system (cptr);
+#if defined (VMS)
+printf ("\n");
+#endif
+
 return SCPE_OK;
 }
 
@@ -1177,7 +1190,7 @@ return ssh_break (NULL, cptr, flg);			/* call common code */
 
 t_stat ssh_break (FILE *st, char *cptr, int32 flg)
 {
-char gbuf[CBUFSIZE], *tptr, *t1ptr;
+char gbuf[CBUFSIZE], *tptr, *t1ptr, *aptr;
 DEVICE *dptr = sim_devices[0];
 UNIT *uptr = dptr->units;
 t_stat r;
@@ -1187,6 +1200,9 @@ int32 cnt;
 if (*cptr == 0) return SCPE_2FARG;
 if (sim_brk_types == 0) return SCPE_NOFNC;
 if ((dptr == NULL) || (uptr == NULL)) return SCPE_IERR;
+if (aptr = strchr (cptr, ';')) {			/* ;action? */
+	if (flg != SSH_ST) return SCPE_ARG;		/* only on SET */
+	*aptr++ = 0;  }					/* separate strings */
 while (*cptr) {
     cptr = get_glyph (cptr, gbuf, ',');
     tptr = get_range (gbuf, &lo, &hi, dptr->aradix, max, 0);
@@ -1205,7 +1221,7 @@ while (*cptr) {
 	else return SCPE_ARG;  }
     else {	
 	for ( ; lo <= hi; lo = lo + dptr->aincr) {
-	    if (flg == SSH_ST) r = sim_brk_set (lo, sim_switches, cnt);
+	    if (flg == SSH_ST) r = sim_brk_set (lo, sim_switches, cnt, aptr);
 	    else if (flg == SSH_CL) r = sim_brk_clr (lo, sim_switches);
 	    else if (flg == SSH_SH) r = sim_brk_show (st, lo, sim_switches);
 	    else return SCPE_ARG;
@@ -1788,6 +1804,7 @@ if ((r = sim_check_console (30)) != SCPE_OK) {		/* check console, error? */
 	return r;  }
 if (step) sim_activate (&step_unit, step);		/* set step timer */
 sim_is_running = 1;					/* flag running */
+sim_brk_act = NULL;					/* defang actions */
 r = sim_instr();
 
 sim_is_running = 0;					/* flag idle */
@@ -3206,7 +3223,7 @@ return sim_rtcn_calb (ticksper, 0);
 	type			types of breakpoints set on the address
 				a bit mask representing letters A-Z
 	cnt			number of iterations before breakp is taken
-	action			pointer to list of commands to be executed
+	action			pointer command string to be executed
 				when break is taken
 
    sim_brk_summ is a summary of the types of breakpoints that are currently set (it
@@ -3216,7 +3233,6 @@ return sim_rtcn_calb (ticksper, 0);
    The package contains the following public routines:
 
 	sim_brk_init		initialize
-	sim_brk_pchg		PC change
 	sim_brk_set		set breakpoint
 	sim_brk_clr		clear breakpoint
 	sim_brk_clrall		clear all breakpoints
@@ -3225,17 +3241,17 @@ return sim_rtcn_calb (ticksper, 0);
 	sim_brk_test		test for breakpoint
 	sim_brk_npc		PC has been changed
 
-   Initialize breakpoint system.  If simulator has filled in sim_brk_types,
-   allocate an initial breakpoint table, otherwise, allocate a minimal table.
+   Initialize breakpoint system.
 */
 
 t_stat sim_brk_init (void)
 {
-if (sim_brk_types) sim_brk_lnt = SIM_BRK_INILNT;
-else sim_brk_lnt = 1;
+sim_brk_lnt = SIM_BRK_INILNT;
 sim_brk_tab = calloc (sim_brk_lnt, sizeof (BRKTAB));
 if (sim_brk_tab == NULL) return SCPE_MEM;
 sim_brk_ent = sim_brk_ins = 0;
+sim_brk_pend = FALSE;
+sim_brk_act = NULL;
 return SCPE_OK;
 }
 
@@ -3266,10 +3282,19 @@ return NULL;
 
 BRKTAB *sim_brk_new (t_addr loc)
 {
-BRKTAB *bp;
+int32 i, t;
+BRKTAB *bp, *newp;
 
 if (sim_brk_ins < 0) return NULL;
-if (sim_brk_ent >= sim_brk_lnt) return NULL;
+if (sim_brk_ent >= sim_brk_lnt) {			/* out of space? */
+	t = sim_brk_lnt + SIM_BRK_INILNT;		/* new size */
+	newp = calloc (t, sizeof (BRKTAB));		/* new table */
+	if (newp == NULL) return NULL;			/* can't extend */
+	for (i = 0; i < sim_brk_lnt; i++)		/* copy table */
+	    *(newp + i) = *(sim_brk_tab + i);
+	free (sim_brk_tab);				/* free old table */
+	sim_brk_tab = newp;				/* new base, lnt */
+	sim_brk_lnt = t;  }
 if (sim_brk_ins != sim_brk_ent) {			/* move needed? */
 	for (bp = sim_brk_tab + sim_brk_ent;
 	     bp > sim_brk_tab + sim_brk_ins; bp--)
@@ -3285,17 +3310,25 @@ return bp;
 
 /* Set a breakpoint of type sw */
 
-t_stat sim_brk_set (t_addr loc, int32 sw, int32 ncnt)
+t_stat sim_brk_set (t_addr loc, int32 sw, int32 ncnt, char *act)
 {
 BRKTAB *bp;
 
 if (sw == 0) sw = sim_brk_dflt;
 if ((sim_brk_types & sw) == 0) return SCPE_NOFNC;
-bp = sim_brk_fnd (loc);
-if (!bp) bp = sim_brk_new (loc);
-if (!bp) return SCPE_MEM;
-bp->typ = sw;
-bp->cnt = ncnt;
+bp = sim_brk_fnd (loc);					/* present? */
+if (!bp) bp = sim_brk_new (loc);			/* no, allocate */
+if (!bp) return SCPE_MEM;				/* still no? mem err */
+bp->typ = sw;						/* set type */
+bp->cnt = ncnt;						/* set count */
+if ((bp->act != NULL) && (act != NULL)) {		/* replace old action? */
+	free (bp->act);					/* deallocate */
+	bp->act = NULL;  }				/* now no action */
+if ((act != NULL) && (*act != 0)) {			/* new action? */
+	char *newp = calloc (CBUFSIZE, sizeof (char));	/* allocate buffer */
+	if (newp == NULL) return SCPE_MEM;		/* mem err? */
+	strncpy (newp, act, CBUFSIZE);			/* copy action */
+	bp->act = newp;  }				/* set pointer */
 sim_brk_summ = sim_brk_summ | sw;
 return SCPE_OK;
 }
@@ -3306,14 +3339,15 @@ t_stat sim_brk_clr (t_addr loc, int32 sw)
 {
 BRKTAB *bp = sim_brk_fnd (loc);
 
-if (!bp) return SCPE_OK;
+if (!bp) return SCPE_OK;				/* not there? ok */
 if (sw == 0) sw = SIM_BRK_ALLTYP;
 bp->typ = bp->typ & ~sw;
-if (bp->typ) return SCPE_OK;
-for ( ; bp < (sim_brk_tab + sim_brk_ent - 1); bp++)
+if (bp->typ) return SCPE_OK;				/* clear all types? */
+if (bp->act != NULL) free (bp->act);			/* deallocate action */
+for ( ; bp < (sim_brk_tab + sim_brk_ent - 1); bp++)	/* erase entry */
 	*bp = *(bp + 1);
-sim_brk_ent = sim_brk_ent - 1;
-sim_brk_summ = 0;
+sim_brk_ent = sim_brk_ent - 1;				/* decrement count */
+sim_brk_summ = 0;					/* recalc summary */
 for (bp = sim_brk_tab; bp < (sim_brk_tab + sim_brk_ent); bp++)
 	sim_brk_summ = sim_brk_summ | bp->typ;
 return SCPE_OK;
@@ -3326,9 +3360,9 @@ t_stat sim_brk_clrall (int32 sw)
 BRKTAB *bp;
 
 if (sw == 0) sw = SIM_BRK_ALLTYP;
-if ((sim_brk_summ & ~sw) == 0) sim_brk_ent = sim_brk_summ = 0;
-else {	for (bp = sim_brk_tab; bp < (sim_brk_tab + sim_brk_ent); bp++) {
-	if (bp->typ & sw) sim_brk_clr (bp->addr, sw);  }  }
+for (bp = sim_brk_tab; bp < (sim_brk_tab + sim_brk_ent); ) {
+	if (bp->typ & sw) sim_brk_clr (bp->addr, sw);
+	else bp++;  }
 return SCPE_OK;
 }
 
@@ -3352,6 +3386,7 @@ for (i = any = 0; i < 26; i++) {
 	    fputc (i + 'A', st);
 	    any = 1;  }  }
 if (bp->cnt > 0) fprintf (st, " [%d]", bp->cnt);
+if (bp->act != NULL) fprintf (st, "; %s", bp->act);
 fprintf (st, "\n");
 return SCPE_OK;
 }
@@ -3374,13 +3409,14 @@ t_bool sim_brk_test (t_addr loc, int32 btyp)
 {
 BRKTAB *bp;
 
-if ((bp = sim_brk_fnd (loc)) &&
-    (btyp & bp->typ) &&
-    (!sim_brk_pend || (loc != sim_brk_ploc)) &&
-    (--(bp->cnt) <= 0)) {
-	bp->cnt = 0;
-	sim_brk_ploc = loc;
-	sim_brk_pend = TRUE;
+if ((bp = sim_brk_fnd (loc)) &&				/* entry in table? */
+    (btyp & bp->typ) &&					/* type match? */
+    (!sim_brk_pend || (loc != sim_brk_ploc)) &&		/* new location? */
+    (--(bp->cnt) <= 0)) {				/* count reach 0? */
+	bp->cnt = 0;					/* reset count */
+	sim_brk_ploc = loc;				/* save location */
+	sim_brk_act = bp->act;				/* set up actions */
+	sim_brk_pend = TRUE;				/* don't do twice */
 	return TRUE;  }
 sim_brk_pend = FALSE;
 return FALSE;
diff --git a/sim_rev.h b/sim_rev.h
index 196638ff..3ae3280c 100644
--- a/sim_rev.h
+++ b/sim_rev.h
@@ -29,12 +29,48 @@
 
 #define	SIM_MAJOR	2
 #define SIM_MINOR	10
-#define SIM_PATCH	2
+#define SIM_PATCH	3
 
 /* V2.10 revision history 
 
 patch	date		module(s) and fix(es)
 
+  3	tbd		scp.c:
+			-- added dynamic extension of the breakpoint table
+			-- added breakpoint actions
+
+			hp2100_cpu.c: fixed last cycle bug in DMA output (found by
+			Mike Gemeny)
+
+			hp2100_ipl.c: individual links are full duplex (found by
+			Mike Gemeny)
+
+			pdp11_cpu.c: changed R, SP to track PSW<rs,cm> respectively
+
+			pdp18b_defs.h, pdp18b_sys.c: added RB09 fixed head disk,
+			LP09 printer
+
+			pdp18b_rf.c:
+			-- fixed IOT decoding (found by Hans Pufal)
+			-- fixed address overrun logic
+			-- added variable number of platters and autosizing
+
+			pdp18b_rf.c:
+			-- fixed IOT decoding
+			-- fixed bug in command initiation
+
+			pdp18b_rb.c: new RB09 fixed head disk
+
+			pdp18b_lp.c: new LP09 line printer
+
+			pdp8_df.c: added variable number of platters and autosizing
+
+			pdp8_rf.c: added variable number of platters and autosizing
+
+			nova_dsk.c: added variable number of platters and autosizing
+
+			id16_cpu.c: fixed bug in SETM, SETMR (found by Mark Pizzolato)
+
   2     15-Jan-03	scp.c:
 			-- added dynamic memory size flag and RESTORE support
 			-- added EValuate command
diff --git a/simh_doc.txt b/simh_doc.txt
index 756bd75b..b665070a 100644
--- a/simh_doc.txt
+++ b/simh_doc.txt
@@ -1,7 +1,7 @@
 To:	Users
 From:	Bob Supnik
-Subj:	Simulator Usage, V2.10-2
-Date:	15-Jan-2003
+Subj:	Simulator Usage, V2.10-3
+Date:	15-Feb-2003
 
 			COPYRIGHT NOTICE
 
@@ -490,13 +490,15 @@ breakpoints of different types, identified by letter (for example, E
 for execution, R for read, W for write, etc).  At the moment, most
 simulators support only E (execution) breakpoints.
 
-Associated with a breakpoint is a count.  Each time the breakpoint
-is sprung, the associated count is decremented.  If the count is less
-than or equal to 0, the breakpoint occurs; otherwise, it is deferred.
+Associated with a breakpoint is a count and, optionally, an action.
+Each time the breakpoint is sprung, the associated count is decremented.
+If the count is less than or equal to 0, the breakpoint occurs; otherwise,
+it is deferred.  When the breakpoint occurs, the optional action is
+automatically executed
 
 A breakpoint is set by the BREAK command:
 
-	sim> BREAK {-types} <addr range>{[count]},{addr range...}
+	sim> BREAK {-types} <addr range>{[count]},{addr range...}{;action}
 
 If no type is specified, the simulator-specific default breakpoint
 type (usually E for execution) is used.  As with EXAMINE and DEPOSIT,
@@ -506,6 +508,9 @@ or a relative range of address/length.  Examples of BREAK:
 	sim> break -e 200		-- set E break at 200
 	sim> break 2000/2[2]		-- set E breaks at 2000,2001
 					   with count = 2
+	sim> break 100;ex ac		-- set E break at 100 with
+					   action EX AC
+	sim> break 100;			-- delete action on break at 100
 
 Currently set breakpoints can be displayed with the SHOW BREAK command:
 
@@ -800,7 +805,9 @@ Rev 2.10, Nov, 02
 		Added PDP-11/VAX autoconfiguration support
 		Added PDP-10/PDP-11/VAX variable vector support
 		Added PDP-1 DECtape
+		Added PDP-1, PDP-4 Type 24 serial drum support
 		Added PDP-8 RX28 support
+		Added PDP-9 RB09 fixed head disk, LP09 line printer
 		Added HP2100 12845A line printer
 		Added HP2100 13183 magtape support
 		Added HP2100 boot ROM support
diff --git a/simh_swre.txt b/simh_swre.txt
index b5fa8774..8e89ba3d 100644
--- a/simh_swre.txt
+++ b/simh_swre.txt
@@ -1,7 +1,7 @@
 To:	Users
 From:	Bob Supnik
 Subj:	Sample Software Packages
-Date:	15-Nov-2002
+Date:	15-Feb-2003
 
 This memorandum documents the sample software packages available to run
 with the SIMH simulators.  Many of these packages are available under
@@ -10,8 +10,8 @@ software.
 
 The following copyright notice applies to both the SIMH source and binary:
 
-   Original code published in 1993-2002, written by Robert M Supnik
-   Copyright (c) 1993-2002, Robert M Supnik
+   Original code published in 1993-2003, written by Robert M Supnik
+   Copyright (c) 1993-2003, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -354,6 +354,12 @@ development and execution capabilities.  To load and run ADSS/KM-15:
 	sim> ex pc
 	PC:	077646
 
+- Change the default line printer to be the LP09 rather than the Type
+  647 (PDP-9) or LP15 (PDP-15):
+
+	sim> set lpt disa
+	sim> set lp9 ena
+
 - Mount the Advanced Software System DECtape image on DECtape unit 0:
 
 	sim> attach dt adss15_32k.dtp
@@ -445,6 +451,36 @@ does not support the SIMH sockets library.
 
    and is now ready for commands.
 
+6.4 DOS-15
+
+DOS-15 was a more polished version of ADSS-15 using the RF15 or RP15
+as its system device.  To load and run DOS-15:
+
+- Load the DOS-15 paper tape bootstrap into upper memory:
+
+	sim> load rfsboot.rim 77637
+
+- Mount the DOS-15 RF disk image on the RF15:
+
+	sim> att rf dosv2a_4p.rf
+
+- Run the bootstrap:
+
+	sim> run
+
+- The RF disk will boot and print out
+
+DOS-15 V2A
+ ENTER DATE (MM/DD/YY) -
+
+  Enter the date (the year must be between 70 and 99).  DOS-15 will
+  print its prompt and is now ready for commands.  Recognized commands
+  include:
+
+	I	system information
+	S	system configuration
+	R	system device assignments
+
 
 7. IBM 1401