The Sol-20 provides 1K RAM at C800. This was discovered to be missing
when issuing a "SET CPU 24K" command. Without the CPU providing RAM
at C800, the Sol-20 would not function. This PR corrects the problem
by having the SOL20 device provide its own 1K RAM at C800.
- Make sure that asynchronous mode can't be changed if devices using
sim_ether are already attached.
- Add missing DEV_ETHER type flag for the only sim_ether using device
that didn't already have it.
I7010 updated to pass diagnostics.
I7080 updated to pass diagnostics.
I7090 updated to better pass 9IOT
updated to allow Stress and other applications to run better.
Updated card punch to allow input of card decks for overpunching.
- Without regard to whether the circular buffer data is otherwise in
use while instructions are executing.
- When a circular debug buffer is in use, avoid writing out the contents
with the periodic open file flushes and only do so on returns to the
sim> prompt and when debug is closed
A user observed that the TS11 would not run XXDP+, even though it ran
fine with the PDP11 operating systems, VMS, and XXDP V2. I traced this
back to a conceptual error in the implementation of some magtapes,
specifically the TS11, RH11/TM02-3, and the PDP10 TU45.
The issues is that beginning of tape, and being positioned in front of
the first record, are not necessarily the same. Following BOT, tape
drives record a ID burst If high density and an inter-record gap before
the first record. When the first record is read backwards or backspaced
over, the tape ends up at position 0 but should not show BOT. Most
simulated tape drives did this correctly, but a few used sim_tape_bot()
as a shortcut for BOT, and it's simply not correct.
BOT should be set at ATTACH, by a successful rewind, and by any reverse
operation when the tape is positioned in front of the first record.
BOT should be cleared by any successful movement operation, except
rewind.
- On MacOS, avoid Homebrew updating other pre-installed packages.
Autoupdating packages that aren't needed or referenced by the build
can take a very long time and cause the build timeout to be exceeded.
- Be sure to only save build results for changes to the master branch
of simh/simh
- Avoid saving binaries when one has been saved within the last week
17 777 740 - 17 777 742, read-only error address registers,
and 17 777 764, a read-only System ID register,
and are not handled in the CPU70_wr() routine, which means for these
addresses the routine returns NXM, which then translates to "bus timeout"
(no response to address), and then, as a result, trap to vector 4.
That is incorrect, IMO.
These locations are read-only yet the address gets decoded, and even
though writing does not have any effect, the write routine for these
addresses should return SCPE_OK.
sim_instr does not completely follow the outline in the SIMH v3
developer docs. It does not decrease sim_interval in readin mode.
Fixing this, I cleaned up some other things:
- Move the decrease of sim_interval to after the check for breakpoints,
but before the check for ios. This ensures that sim_interval will
decrease any time an instruction executes in normal mode, or readin
mode executes, or ios is set and the CPU is waiting for ios to clear.
(Except the CPU should be clearing ios itself, not waiting for ios to
clear, but that fix requires a complete redesign of the I/O routines
and belongs in another branch.)
- Correctly handle all four combinations of mod_tst and mod_rdin.
- When changing from readin mode to normal mode, if cpu_set_mode returns
an error, stop with the same error. If cpu_set_mode returns SCPE_OK,
either stop or continue execution, depending on the word read from tape.
- In petr_boot and in the readin mode code in sim_instr, if the
PETR is not attached to a file, return SCPE_UNATT. Never try to read
from an unattached unit; I believe this reads standard input and
prevents ^E from working.
Overall control structure inside the while (reason == 0) loop:
- When stopping due to an error, break out of the while loop where
possible.
- After handling "ios is set", continue, don't run readin/test/normal-
mode code.
- After handling one readin operation, if the code didn't break out
of the while loop, continue, don't run normal-mode code.
sim_instr never clears it and simulation loops.
The CPU-to-device routines and device service routines need a redesign.
In the meantime, this quick patch makes tape punching possible.
Before, when the simulator decoded pad, it handled pad without cry
and pad with cry. When it decoded cry, it printed a "TO DO" message.
http://bitsavers.org/pdf/mit/tx-0/memos/M-5001-19_macros_Apr60.pdf
derives a simple algorithm for cry. Implement that, remove the test
for cry from the pad code, and reformat the debug messages.
The same change appears in sim_instr and sim_opr_orig.
