These include simulators for the IBM 701, IBM 702, IBM 704, IBM 705,
IBM 705/3, IBM 709, IBM 1410/IBM 7010, IBM 7070, IBM 7080, IBM 7090
and IBM7094.
These basically were a collection of machines that shared a common
set it peripherals, Each group had its own instruction set, hence
different simulators.
IBM 701 -> i701
IBM 702/705/705/3/7080 -> i7080
IBM 7070/7074 -> i7070
IBM 1410/7010 -> i7010
IBM 704 -> i704
IBM 704/709/7090/7094 -> i7090
The i7090 can be set to simulate a IBM 704 however you end up
disabling almost everything, since the 704 did not have any channels.
A build option exists that allows this one to be built without all the
extra features.
The i7090 simulator’s implementation of the IBM 7094 is a more
complete implementation of the IBM 7094 which can run CTSS
while the existing simh I7094 can’t.
%% now inserts a bare % and \\ only means something when parsing a quoted
string argument (used by EXPECT and SEND commands).
Additionally, EXPECT and BREAK commands have action steps which will now
expand arguments as each of the actions are executed rather than when the
EXPECT or BREAK command is defined.
With this update, the erase gap operation has been split out of
"sim_tape_wrgap" into a separate, internal "tape_erase_fwd" routine that
is called from "sim_tape_wrgap" as well as from the new "sim_tape_errecf"
routine. There's a corresponding internal "tape_erase_rev" that's called
from the new "sim_tape_errecr" routine.
I've shimmed "sim_tape_rdlntf" and "sim_tape_rdlntr" to move the tape
context and debug stuff out of the routines that I'm maintaining. This
will allow me to replace those functions in their entirety with the
corresponding functions in my development sources for future updates.
It also allows me to keep Bob's version in sync. As my routines are static
and only called once from the shims, compilers should optimize away
the function calls and instead inline the code, so there'd be no extra call
overhead.
I'd also like to keep "tape_erase_fwd" and "tape_erase_rev" untouched for
the same reason. If you wish to add debug calls to "sim_tape_errecf" and
"sim_tape_errecr", that's fine.
The major change is the implementation of deferred IO - a more
accurate implementation of the 1620's "stop in its tracks" IO model.
When a device uses deferred IO, instruction execution is suspended
until the IO completes successfully. Operator interruptions, errors,
and so on do not return to instruction execution; this only occurs if
the IO completes successfully or the command SET CPU RELEASE is given
(equivalent of pressing the RELEASE button). Otherwise, the current IO
operation continues to execute.
Only the console typewriter and paper tape reader/punch currently
implement deferred IO; there are operational issues with those devices
that require more accurate modeling. The card reader/punch, line
printer, and disk still execute IO "instantaneously". It's not all
that hard to convert an instantaneous device to deferred operation,
but there's no point in doing so (and possibly introducing new bugs)
unless there's an actual operational issue. The 1620 doesn't have
overlapped IO, so programs can't tell the difference, by and large.
A number of other issues have been addressed as well, including the
bizarre "treat RM as 0 in the Q field" required by MI-015; the
treatment of non-existent indicators as always off; and various other
tweaks.
I've run CU01 (again), which at least gives typewriter and paper-tape
IO a basic workout; and it works. I leave more detailed testing to
people who know the machine better than I do.
The documentation has been updated to include Tom's detailed breakdown
of IO handling for all IO operations on the typewriter, paper-tape
reader/punch, card reader/punch, and line printer.
- Add support to query remaining usecs on pending events.
- Generalized the sim_interval adjustment in sim_idle to allow more than
a single decrement.
- More overhead reduction when idling.
- Carry usec values as double through out to fully support long wall clock
delays.
commit ef6528bf32 added support for automatic WRU detection for simulators
that don't have a console port, but it was never documented and the addition of
that support potentially interfered with SAVE/RESTORE behavior.
The console connection state is now automatically saved and restored.
The output of remote console commands gets truncated at the configured
buffer size. The default has been raised from 1400 to 8192.
Common remote console usage is from the same host as the simulator and
as such localhost TCP traffic is delivered in chunks at least 8192 so no extra
packets will be involved in transporting the potential extra data and no
transmission delays on the send() call.
The minumum size is now 1400 (which was the prior default).
The RUN command implicitly resets all devices which may have unexpected
consequences for a novice user.
The logic now produces a warning about this side effect when more than one
RUN command is executed in the same simulator session.
An explicit RESET command suppresses this warning for a subsequent RUN
command.
A RUN command with the -Q switch also suppresses this warning.
Asynchronous clocks are now built for all simulators which are built with
SIM_ASYNCH_IO defined. The default behavior has asynchronous clocks
disabled since this is still experimental, but it can be enabled with
SET TIMER ASYNC.
Catchup clock ticks are now available, but since they're experimental,
they aren't enabled by default. Catchup ticks are only available if the
simulators clock device calls sim_rtcn_tick_ack to acknowledge processing
of clock ticks. The VAX simulators have been modified to leverage this.
Catchup clock ticks can be enabled with SET TIMER CATCHUP
Additionally, an idle threshold is provided which can be used to
influence when clock calibration may be suppressed. The default is not
to suppress calibration activities.
The various timer behaviors are visible with the SHOW TIMER command.
The state of the operating timer facilities is visible with: SHOW CLOCK
Timer events which are queued are visible with the SHOW QUEUE command.
