Here's a PDP11 SIMH bug as old as the simulator itself: the reset_cpu routine sets the PS to 340 (interrupts disabled). This causes some versions of Lunar Lander not to work. In fact, the initial state of the PS is not architecturally standardized:
04: cleared (from schematics)
05: cleared (from manual)
20: cleared (from schematics)
34: cleared (from schematics), set to 340 on boot?
40: cleared (from schematics)
44: cleared on init, set to 340 on boot (from schematics, manual)
45: cleared (from schematics)
60: cleared (from schematics)
70: cleared (from schematics)
T11: set to 340 (from spec)
LSI11, F11: 4 mode behavior (from memory on power recovery, cleared on GO, 340 on boot, mode 3 undefined)
J11: 4 mode behavior (from memory on power recovery, cleared on GO, 340 on boot, 340 on jump to custom PROM)
The story seems to be this. All non-VLSI PDP11s used TTL chips to implement the PS, either discrete flip-flops, or 4b registers, or both.
Starting with the first system, the 11/20, they were wired clear on the processor INIT signal (power-up or front panel START switch), so that all internal state started as 0. This worked fine, because START also reset the Unibus and cleared all interrupt enables. So even though the processor was as IPL = 0, no interrupts were possible. Then along came the LSI11...
The LSI11 implemented a line-time clock with NO INTERRUPT DISABLE. Thus, if IPL was left at 0 and a bootstrap routine from a slow device was started (e.g., a floppy drive), the clock would tick, and an interrupt would occur, before the bootstrap routine finished. Because no vectors were set up, the processor would crash. So the LSI11 started the practice, carried over to all later PDP11 VLSI chips, of setting the PS to 340 before jumping to a boot ROM.
The T11 did this in all modes of startup, because its only startup behavior was to jump to a "boot" routine. It did not have a console of any kind.
Accordingly, it appears that the cpu_reset routine needs to set the PS based on the processor model. Further, all boot routines need to set the PS to 0 or 340 based on the processor model. (It's probably safe for boot routines just to set the PS to 340, but it's not technically
accurate.)
Fixed auto configure bugs which didn't allow Fixed CSR Addresses or Fixed Vectors to be set using the auto configure information.
Fixed display of address and vectors to indicate that the assigned address and/or vector is in the floating set.
Added extended definitions to the auto configure table to reflect all known potential static and floating and static addresses as of VMS V5.5-2
Changed the name of the VAX 11/780 console floppy device name to RXC from RX (which collides with a Unibus name for the RX11).
Very minor in all cases, but the strange case of swtp_cpu.c
This module used expressions of the form:
PC = ++PC & ADDRMASK;
Officially, the C language says that expressions which modify the same variable in more than one place have undefined behavior.
These were changed to the legal form which performs the desired action:
PC = (PC + 1) & ADDRMASK;
The makefile now works for Linux and most Unix's. Howevr, for Solaris
and MacOS, you must first export the OSTYPE environment variable:
> export OSTYPE
> make
Otherwise, you will get build errors.
1. New Features
1.1 3.8-0
1.1.1 SCP and Libraries
- BREAK, NOBREAK, and SHOW BREAK with no argument will set, clear, and
show (respectively) a breakpoint at the current PC.
1.1.2 GRI
- Added support for the GRI-99 processor.
1.1.3 HP2100
- Added support for the BACI terminal interface.
- Added support for RTE OS/VMA/EMA, SIGNAL, VIS firmware extensions.
1.1.4 Nova
- Added support for 64KW memory (implemented in third-party CPU's).
1.1.5 PDP-11
- Added support for DC11, RC11, KE11A, KG11A.
- Added modem control support for DL11.
- Added ASCII character support for all 8b devices.
1.2 3.8-1
1.2.1 SCP and libraries
- Added capability to set line connection order for terminal multiplexers.
1.2.2 HP2100
- Added support for 12620A/12936A privileged interrupt fence.
- Added support for 12792C eight-channel asynchronous multiplexer.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
1. New Features
1.1 3.7-0
1.1.1 SCP
- Added SET THROTTLE and SET NOTHROTTLE commands to regulate simulator
execution rate and host resource utilization.
- Added idle support (based on work by Mark Pizzolato).
- Added -e to control error processing in nested DO commands (from
Dave Bryan).
1.1.2 HP2100
- Added Double Integer instructions, 1000-F CPU, and Floating Point
Processor (from Dave Bryan).
- Added 2114 and 2115 CPUs, 12607B and 12578A DMA controllers, and
21xx binary loader protection (from Dave Bryan).
1.1.3 Interdata
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state.
1.1.4 PDP-11
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (WAIT instruction executed).
- Added TA11/TU60 cassette support.
1.1.5 PDP-8
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
- Added TA8E/TU60 cassette support.
1.1.6 PDP-1
- Added support for 16-channel sequence break system.
- Added support for PDP-1D extended features and timesharing clock.
- Added support for Type 630 data communications subsystem.
1.1.6 PDP-4/7/9/15
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
1.1.7 VAX, VAX780
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (more than 200 cycles at IPL's 0, 1, or 3 in kernel mode).
1.1.8 PDP-10
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (operating system dependent).
- Added CD20 (CD11) support.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
1. New Features
1.1 3.7-0
1.1.1 SCP
- Added SET THROTTLE and SET NOTHROTTLE commands to regulate simulator
execution rate and host resource utilization.
- Added idle support (based on work by Mark Pizzolato).
- Added -e to control error processing in nested DO commands (from
Dave Bryan).
1.1.2 HP2100
- Added Double Integer instructions, 1000-F CPU, and Floating Point
Processor (from Dave Bryan).
- Added 2114 and 2115 CPUs, 12607B and 12578A DMA controllers, and
21xx binary loader protection (from Dave Bryan).
1.1.3 Interdata
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state.
1.1.4 PDP-11
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (WAIT instruction executed).
- Added TA11/TU60 cassette support.
1.1.5 PDP-8
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
- Added TA8E/TU60 cassette support.
1.1.6 PDP-1
- Added support for 16-channel sequence break system.
- Added support for PDP-1D extended features and timesharing clock.
- Added support for Type 630 data communications subsystem.
1.1.6 PDP-4/7/9/15
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
1.1.7 VAX, VAX780
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (more than 200 cycles at IPL's 0, 1, or 3 in kernel mode).
1.1.8 PDP-10
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (operating system dependent).
- Added CD20 (CD11) support.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
1. New Features
1.1 3.7-0
1.1.1 SCP
- Added SET THROTTLE and SET NOTHROTTLE commands to regulate simulator
execution rate and host resource utilization.
- Added idle support (based on work by Mark Pizzolato).
- Added -e to control error processing in nested DO commands (from
Dave Bryan).
1.1.2 HP2100
- Added Double Integer instructions, 1000-F CPU, and Floating Point
Processor (from Dave Bryan).
- Added 2114 and 2115 CPUs, 12607B and 12578A DMA controllers, and
21xx binary loader protection (from Dave Bryan).
1.1.3 Interdata
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state.
1.1.4 PDP-11
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (WAIT instruction executed).
- Added TA11/TU60 cassette support.
1.1.5 PDP-8
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
- Added TA8E/TU60 cassette support.
1.1.6 PDP-1
- Added support for 16-channel sequence break system.
- Added support for PDP-1D extended features and timesharing clock.
- Added support for Type 630 data communications subsystem.
1.1.6 PDP-4/7/9/15
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (keyboard poll loop or jump-to-self).
1.1.7 VAX, VAX780
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (more than 200 cycles at IPL's 0, 1, or 3 in kernel mode).
1.1.8 PDP-10
- Added SET IDLE and SET NOIDLE commands to idle the simulator in wait
state (operating system dependent).
- Added CD20 (CD11) support.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
The save/restore format has been updated to improve its reliability.
As a result, save files prior to release 3.0 are no longer supported.
The text documentation files are obsolete and are no longer included
with the distribution. Up-to-date PDF documentation files are
available on the SimH web site.
1. New Features
1.1 3.6-0
1.1.1 Most magnetic tapes
- Added support for limiting tape capacity to a particular size in MB
1.1.2 IBM 7090/7094
- First release
1.1.3 VAX-11/780
- Added FLOAD command, loads system file from console floppy disk
1.1.4 VAX, VAX-11/780, and PDP-11
- Added card reader support (from John Dundas)
1.1.5 PDP-11
- Added instruction history
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
The source set has been extensively overhauled. For correct
viewing, set Visual C++ or Emacs to have tab stops every 4
characters.
1. New Features
1.1 3.5-0
1.1.1 All Ethernet devices
- Added Windows user-defined adapter names (from Timothe Litt)
1.1.2 Interdata, SDS, HP, PDP-8, PDP-18b terminal multiplexors
- Added support for SET <unit>n DISCONNECT
1.1.3 VAX
- Added latent QDSS support
- Revised autoconfigure to handle QDSS
1.1.4 PDP-11
- Revised autoconfigure to handle more cases
1.2 3.5-1
No new features
1.3 3.5-2
1.3.1 All ASCII terminals
- Most ASCII terminal emulators have supported 7-bit and 8-bit
operation; where required, they have also supported an upper-
case only or KSR-emulation mode. This release adds a new mode,
7P, for 7-bit printing characters. In 7P mode, non-printing
characters in the range 0-31 (decimal), and 127 (decimal), are
automatically suppressed. This prevents printing of fill
characters under Windows.
The printable character set for ASCII code values 0-31 can be
changed with the SET CONSOLE PCHAR command. Code value 127
(DELETE) is always suppressed.
1.3.2 VAX-11/780
- First release. The VAX-11/780 has successfully run VMS V7.2. The
commercial instructions and compatability mode have not been
extensively tested. The Ethernet controller is not working yet
and is disabled.
2. Bugs Fixed
2.1 3.5-0
2.1.1 SCP and libraries
- Trim trailing spaces on all input (for example, attach file names)
- Fixed sim_sock spurious SIGPIPE error in Unix/Linux
- Fixed sim_tape misallocation of TPC map array for 64b simulators
2.1.2 1401
- Fixed bug, CPU reset was clearing SSB through SSG
2.1.3 PDP-11
- Fixed bug in VH vector display routine
- Fixed XU runt packet processing (found by Tim Chapman)
2.1.4 Interdata
- Fixed bug in SHOW PAS CONN/STATS
- Fixed potential integer overflow exception in divide
2.1.5 SDS
- Fixed bug in SHOW MUX CONN/STATS
2.1.6 HP
- Fixed bug in SHOW MUX CONN/STATS
2.1.7 PDP-8
- Fixed bug in SHOW TTIX CONN/STATS
- Fixed bug in SET/SHOW TTOXn LOG
2.1.8 PDP-18b
- Fixed bug in SHOW TTIX CONN/STATS
- Fixed bug in SET/SHOW TTOXn LOG
2.1.9 Nova, Eclipse
- Fixed potential integer overflow exception in divide
2.2 3.5-1
2.2.1 1401
- Changed character encodings to be compatible with Pierce 709X simulator
- Added mode for old/new character encodings
2.2.2 1620
- Changed character encodings to be compatible with Pierce 709X simulator
2.2.3 PDP-10
- Changed MOVNI to eliminate GCC warning
2.2.4 VAX
- Fixed bug in structure definitions with 32b compilation options
- Fixed bug in autoconfiguration table
2.2.5 PDP-11
- Fixed bug in autoconfiguration table
2.3 3.5-2
2.3.1 PDP-10
- RP: fixed drive clear not to clear disk address
2.3.2 PDP-11 (VAX, VAX-11/780, for shared peripherals)
- HK: fixed overlap seek interaction with drive select, drive clear, etc
- RQ, TM, TQ, TS, TU: widened address display to 64b when USE_ADDR64 option selected
- TU: changed default adapter from TM02 to TM03 (required by VMS)
- RP: fixed drive clear not to clear disk address
- RP, TU: fixed device enable/disable to enabled/disable Massbus adapter as well
- XQ: fixed register access alignment bug (found by Doug Carman)
2.3.3 PDP-8
- RL: fixed IOT 61 decoding bug (found by David Gesswein)
- DF, DT, RF: fixed register access alignment bug (found by Doug Carman)
2.3.4 VAX
- Fixed CVTfi to trap on integer overflow if PSW<iv> is set
- Fixed breakpoint detection when USE_ADDR64 option selected
The source set has been extensively overhauled. For correct
viewing, set Visual C++ or Emacs to have tab stops every 4
characters.
1. New Features in 3.4-1
1.1 All Ethernet devices
- Added Windows user-defined adapter names (from Timothe Litt)
1.2 Interdata, SDS, HP, PDP-8, PDP-18b terminal multiplexors
- Added support for SET <unit>n DISCONNECT
1.3 VAX
- Added latent QDSS support
- Revised autoconfigure to handle QDSS
1.4 PDP-11
- Revised autoconfigure to handle more casees
2. Bugs Fixed in 3.4-1
2.1 SCP and libraries
- Trim trailing spaces on all input (for example, attach file names)
- Fixed sim_sock spurious SIGPIPE error in Unix/Linux
- Fixed sim_tape misallocation of TPC map array for 64b simulators
2.2 1401
- Fixed bug, CPU reset was clearing SSB through SSG
2.3 PDP-11
- Fixed bug in VH vector display routine
- Fixed XU runt packet processing (found by Tim Chapman)
2.4 Interdata
- Fixed bug in SHOW PAS CONN/STATS
- Fixed potential integer overflow exception in divide
2.5 SDS
- Fixed bug in SHOW MUX CONN/STATS
2.6 HP
- Fixed bug in SHOW MUX CONN/STATS
2.7 PDP-8
- Fixed bug in SHOW TTIX CONN/STATS
- Fixed bug in SET/SHOW TTOXn LOG
2.8 PDP-18b
- Fixed bug in SHOW TTIX CONN/STATS
- Fixed bug in SET/SHOW TTOXn LOG
2.9 Nova, Eclipse
- Fixed potential integer overflow exception in divide
The memory layout for the Interdata simulators has been changed.
Do not use Interdata SAVE files from prior revisions with V3.4.
1. New Features in 3.4
1.1 SCP and Libraries
- Revised interpretation of fprint_sym, fparse_sym returns
- Revised syntax for SET DEBUG
- DO command nesting allowed to ten levels
1.2 Interdata
- Revised memory model to be 16b instead of 8b
1.3 HP2100
- Added Fast FORTRAN Processor instructions
- Added SET OFFLINE/ONLINE and SET UNLOAD/LOAD commands to tapes and disks
2. Bugs Fixed in 3.4-0
2.1 Interdata
- Fixed bug in show history routine (from Mark Hittinger)
- Fixed bug in initial memory allocation
2.2 PDP-10
- Fixed TU bug, ERASE and WREOF should not clear done (reported by
Rich Alderson)
- Fixed TU error reporting
2.3 PDP-11
- Fixed TU error reporting
RESTRICTION: The HP DS disk is not debugged. DO NOT enable this
feature for normal operations.
WARNING: Massive changes in the PDP-11 make all previous SAVEd
file obsolete. Do not attempt to use a PDP-11 SAVE file from a
prior release with V3.3!
1. New Features in 3.3
1.1 SCP
- Added -p (powerup) qualifier to RESET
- Changed SET <unit> ONLINE/OFFLINE to SET <unit> ENABLED/DISABLED
- Moved SET DEBUG under SET CONSOLE hierarchy
- Added optional parameter value to SHOW command
- Added output file option to SHOW command
1.2 PDP-11
- Separated RH Massbus adapter from RP controller
- Added TU tape support
- Added model emulation framework
- Added model details
1.3 VAX
- Separated out CVAX-specific features from core instruction simulator
- Implemented capability for CIS, octaword, compatibility mode instructions
- Added instruction display and parse for compatibility mode
- Changed SET CPU VIRTUAL=n to SHOW CPU VIRTUAL=n
- Added =n optional parameter to SHOW CPU HISTORY
1.4 Unibus/Qbus simulators (PDP-11, VAX, PDP-10)
- Simplified DMA API's
- Modified DMA peripherals to use simplified API's
1.5 HP2100 (all changes from Dave Bryan)
CPU - moved MP into its own device; added MP option jumpers
- modified DMA to allow disabling
- modified SET CPU 2100/2116 to truncate memory > 32K
- added -F switch to SET CPU to force memory truncation
- modified WRU to be REG_HRO
- added BRK and DEL to save console settings
DR - provided protected tracks and "Writing Enabled" status bit
- added "parity error" status return on writes for 12606
- added track origin test for 12606
- added SCP test for 12606
- added "Sector Flag" status bit
- added "Read Inhibit" status bit for 12606
- added TRACKPROT modifier
LPS - added SET OFFLINE/ONLINE, POWEROFF/POWERON
- added fast/realistic timing
- added debug printouts
LPT - added SET OFFLINE/ONLINE, POWEROFF/POWERON
PTR - added paper tape loop mode, DIAG/READER modifiers to PTR
- added PV_LEFT to PTR TRLLIM register
CLK - modified CLK to permit disable
1.6 IBM 1401, IBM 1620, Interdata 16b, SDS 940, PDP-10
- Added instruction history
1.7 H316, PDP-15, PDP-8
- Added =n optional value to SHOW CPU HISTORY
2. Bugs Fixed in 3.3
2.1 SCP
- Fixed comma-separated SET options (from Dave Bryan)
- Fixed duplicate HELP displays with user-specified commands
2.2 PDP-10
- Replicated RP register state per drive
- Fixed TU to set FCE on short record
- Fixed TU to return bit<15> in drive type
- Fixed TU format specification, 1:0 are don't cares
- Fixed TU handling of TMK status
- Fixed TU handling of DONE, ATA at end of operation
- Implemented TU write check
2.3 PDP-11
- Replicated RP register state per drive
- Fixed RQ, TQ to report correct controller type and stage 1 configuration
flags on a Unibus system
- Fixed HK CS2<output_ready> flag
2.4 VAX
- Fixed parsing of indirect displacement modes in instruction input
2.5 HP2100 (all fixes from Dave Bryan)
CPU - fixed S-register behavior on 2116
- fixed LIx/MIx behavior for DMA on 2116 and 2100
- fixed LIx/MIx behavior for empty I/O card slots
DP - fixed enable/disable from either device
- fixed ANY ERROR status for 12557A interface
- fixed unattached drive status for 12557A interface
- status cmd without prior STC DC now completes (12557A)
- OTA/OTB CC on 13210A interface also does CLC CC
- fixed RAR model
- fixed seek check on 13210 if sector out of range
DQ - fixed enable/disable from either device
- shortened xtime from 5 to 3 (drive avg 156KW/second)
- fixed not ready/any error status
- fixed RAR model
DR - fixed enable/disable from either device
- fixed sector return in status word
- fixed DMA last word write, incomplete sector fill value
- fixed 12610 SFC operation
- fixed current-sector determination
IPL - fixed enable/disable from either device
LPS - fixed status returns for error conditions
- fixed handling of non-printing characters
- fixed handling of characters after column 80
- improved timing model accuracy for RTE
LPT - fixed status returns for error conditions
- fixed TOF handling so form remains on line 0
SYS - fixed display of CCA/CCB/CCE instructions
2.5 PDP-15
FPP - fixed URFST to mask low 9b of fraction
- fixed exception PC setting
