scp.c, scp.h, sim_defs.h
- Added commands:
SHOW MULTIPLEXER (MUX)
SHOW TIMERS
- Added facilities/APIs:
sim_activate_after - time specific event scheduling (vs instruction scheduling) API visible, optional separate thread implementation in a later revision
- Changed Commands:
SET CONSOLE DEBUG no longer affects global debugging, but merely debugging for the console subsystem. Use SET DEBUG and SET NODEBUG to affect global debugging.
- Added Asynchronous polling support
sim_tmxr.h, sim_tmxr.c
- Added Asynchronous capabilities to the multiplexer subsystem to avoid polling for input and to deliver input data instantly when it arrives instead of delaying for up to one or more full simulated clock ticks.
- Added debug trace support
- Added statistic tracking of total bytes transmitted on each line
- Added more aggressive attempts to flush transmit buffers when they fill before dropping tranmitted characters
- Fixed status return of tmxr_putc_ln to return SCPE_LOST if the transmitting line isn't connected or buffered.
sim_console.h, sim_console.c
- Fixed issue where connections to console telnet sessions would succeed for the first connection, but hang indefinitely for additional connects without rejecting due to all lines being busy. This is handled by using an internal device and unit to hang the required polling on. Connection polls happen once per second.
- Added console debugging/trace support.
- Added Asynchronous capabilities to the console subsystem to avoid polling for input and to deliver input data instantly when it arrives instead of delaying for up to one or more full simulated clock ticks.
- Added tmxr_set_console_input_unit() API to support asynchronous simulator console I/O
sim_timer.h, sim_timer.c
- Added SHOW TIMERS support
- Added mechanism to capture the timer the simulator uses for its clock tick and make this timer globally available for other uses
PDP11/pdp11_dz.c
- Added debug trace support
PDP11/pdp11_vh.c
- Added debug trace support
- Changed timing mechanisms to not assume that the count unit service routine calls measures the passage of time, and created a separate unit to measure time.
VAX/vax_stddev.c
- Added call to tmxr_set_console_input_unit to leverage Asynchronous console I/O
- Removed flawed logic which assumed that sim_interval was meaningful when referenced by an asynchronous thread.
- Adjust the event_time of events removed from the asynch queue to account for the average time spent on the queue before the event was noticed by the instruction execution thread.
- Added a sim_activate_notbefore function which specifies an rtime which is the earliest time the event should fire.
- Changed the 'wakeup from idle' logic to force an immediate asynch queue check if the wakeup was not due to a timeout (i.e. it was due to an asynch queue insertion).
- Fixed the descrip.mms to build asynchronous support on AXP and IA64 VMS with kernel threads enabled
Unbound the TODR value from the 100hz clock tick interrupt. TODR now behaves like the original battery backed-up clock and runs with the wall clock, not the simulated instruction clock (except when running ROM diagnostics).
Two operational modes are available:
- Default VMS mode, which is similar to the previous
behavior in that without initializing the TODR it
would default to the value VMS would set it to if
VMS knew the correct time. This would be correct
almost all the time unless a VMS disk hadn't been
booted from for more than a year. This mode
produces strange time results for non VMS OSes on
each system boot.
- OS Agnostic mode. This mode behaves precisely like
the VAX780 TODR and works correctly for all OSes.
This mode is enabled by attaching the TODR to a
battery backup state file for the TOY clock
(i.e. sim> attach TODR TOY_CLOCK). When operating
in OS Agnostic mode, the TODR will initially start
counting from 0 and be adjusted differently when an
OS specifically writes to the TODR. VMS will prompt
to set the time on the initial boot unless the SYSGEN
parameter TIMEPROMPTWAIT is set to 0.
This allows a single simulator executable to be a completely useful component (for those simulators which dynamically load ROM or other boot code).
Meanwhile, we continues to allow the explicit use of a user's preferred ROM or other boot code as well.
A build option is provided in the makefile to not build with the included ROM functionality if desired.
Note: Since NetBSD and OpenBSD are still actively developed operating systems, new versions of
these OSes are moving targets with regard to providing idle detection. At this time, recent versions
of OpenBSD have veered from the traditional OS idle approach taken in the other BSD derived OSes.
Determining a reasonable idle detection pattern does not seem possible for these versions.
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;
I’ve always wanted to have the option to have simulated devices behave
more naturally with respect to I/O operations. By more naturally I
mean that the current simulator model I/O is either polled (for asynchronous
things link Muxes and Network), or it is performed in the middle of some
instruction execution taking possibly many milliseconds (disk and/or tapes).
The existing model creates quite deterministic behavior which helps to debug
and understand issues, but it trades off potential instruction execution
while performing these I/O operations in between instruction execution.
To address this concept (while still retaining the potential advantages of
the original model), I’ve designed an Asynch I/O model extension for simh.
In order to flesh-out and debug this design, I’ve also refactored several
devices to utilize this capability. Please read the attached
0readmeAsynchIO.txt file for concept details about the approach.
In order to make disk devices easy to implement (within or without the
AsynchIO framework), I’ve created a sim_disk.c library which is modeled
on the sim_tape.c library to generalize disk I/O like tape I/O is
generalized in sim_tape.c. This sim_disk.c library now provides that
natural place to implement support for various disk implementation formats
(just like sim_tape support several formats, and one day will be the place
to add direct physical tape access). The current sim_disk library provides
the framework for direct support of 3 different disk formats:
1) standard simh disk format
2) platform specific physical disk access
and 3) platform independent Virtual Disk format.
The Virtual Disk format is an implementation of the format described in
the ”Microsoft Virtual Hard Disk (VHD) Image Format Specification”. The
VHD specification is available for anyone to implement under the "Microsoft
Open Specification Promise" described at
http://www.microsoft.com/interop/osp/default.mspx.
The VHD implementation includes support for:
1) Fixed sized disks
2) Dynamically expanding disks
and 3) Differencing Disks.
Dynamically expanding disks don’t change their “Virtual Size”, but they
don’t consume disk space on the containing storage until the virtual
sectors in the disk are actually written to (i.e. an RA81 or RA92 VHD
with a VMS installed on it may initially only contain 30+ MB of files,
and the resulting VHD will be 30+ MB). The VHD format contains meta data
which describes the virtual device. Amongst this meta data is the simh
device type which the VHD was originally created as. This metadata is
therefore available whenever that VHD is attached to an emulated disk
device in the future so the device type & size can be automatically be
configured.
Sim_disk_attach is used by device emulations to attach a simh/vhd/raw
device to a simulated device. The following simh command switches
are used by the sim_disk_attach API:
-R Attach Read Only.
-E Must Exist (if not specified an attempt to create the
indicated virtual disk will be attempted).
-F Open the indicated disk container in a specific format
(default is to autodetect VHD defaulting to simh if the
indicated container is not a VHD).
-X When creating a VHD, create a fixed sized VHD (vs a
Dynamically expanding one).
-C Create a VHD and copy its contents from another disk
(simh, VHD, or RAW format).
-D Create a Differencing VHD (relative to an already
existing VHD disk)
Examples:
sim> show rq
RQ, address=20001468-2000146B*, no vector, 4 units
RQ0, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ1, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ2, 159MB, not attached, write enabled, RD54, autosize, SIMH format
RQ3, 409KB, not attached, write enabled, RX50, autosize, SIMH format
sim> atta rq0 RA81.vhd
sim> show rq0
RQ0, 456MB, attached to RA81.vhd, write enabled, RA81, autosize, VHD format
sim> set rq2 ra92
sim> att rq2 -f vhd RA92.vhd
RQ2: creating new file
sim> sho rq2
RQ2, 1505MB, attached to RA92.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 12:57 PM 5,120 RA92.vhd
1 File(s) 5,120 bytes
0 Dir(s) 3,074,412,544 bytes free
sim> atta rq3 -c RA92-1.vhd RA92.vhd
sim> atta rq3 -c RA92-1.vhd RA92.vhd
RQ3: creating new virtual disk 'RA92-1.vhd'
RQ3: Copied 1505MB. 99% complete.
RQ3: Copied 1505MB. Done.
sim> sh rq3
RQ3, 1505MB, attached to RA92-1.vhd, write enabled, RA92, autosize, VHD format
sim> ! dir RA92*
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:12 PM 5,120 RA92-1.vhd
04/14/2011 12:58 PM 5,120 RA92.vhd
2 File(s) 10,240 bytes
0 Dir(s) 3,074,404,352 bytes free
sim> sho rq2
RQ2, 1505MB, not attached, write enabled, RA92, autosize, VHD format
sim> set rq2 ra81
sim> set rq2 noauto
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, VHD format
sim> set rq2 format=simh
sim> sho rq2
RQ2, 456MB, not attached, write enabled, RA81, noautosize, SIMH format
sim> atta rq2 -c RA81-Copy.vhd VMS055.dsk
RQ2: creating new virtual disk 'RA81-Copy.vhd'
RQ2: Copied 456MB. 99% complete.
RQ2: Copied 456MB. Done.
sim> sho rq2
RQ2, 456MB, attached to RA81-Copy.vhd, write enabled, RA81, noautosize, VHD format
sim> det rq2
sim> ! dir RA81-Copy.vhd
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
04/14/2011 01:22 PM 178,304,512 RA81-Copy.vhd
1 File(s) 178,304,512 bytes
0 Dir(s) 2,896,097,280 bytes free
sim> ! dir VMS055.dsk
Volume in drive H is New Volume
Volume Serial Number is F8DE-510C
Directory of H:\Data
03/08/2011 01:42 PM 403,663,872 VMS055.dsk
1 File(s) 403,663,872 bytes
0 Dir(s) 2,896,097,280 bytes free
sim>
The makefile now works for Linux and most Unix's. However, 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.
1.3 3.8-2
1.3.1 SCP and libraries
- Added line history capability for *nix hosts.
- Added "SHOW SHOW" and "SHOW <dev> SHOW" commands.
1.3.2 1401
- Added "no rewind" option to magtape boot.
1.3.3 PDP-11
- Added RD32 support to RQ
- Added debug support to RL
1.3.4 PDP-8
- Added FPP support (many thanks to Rick Murphy for debugging the code)
1.3.5 VAX-11/780
- Added AUTORESTART switch support, and VMS REBOOT command support
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
