1) a RELEASE is documented (in our limited case) to be equivalent to a CLEAR not a NOP.
2) avoid setting Attention as a consequence of processing an UNLOAD command.
3) extended debugging information needed while looking for an issue which turned out to be a bug in the vax 780 Massbus interrupt triggering logic.
scp.c, scp.h
- added sim_uname (Unit Name) API to simplify places which might want to display it (mostly debug messages).
- added support for clock co-scheduling
- added debugging to trace event queue activities
sim_defs.h
- added support for clock co-scheduling
- added support for sim_uname (Thread local storage macro)
- added support for debugging to trace event queue activities
- simplified debug code by using sim_uname
- fixed support macro for sim_is_active when asynch timers are in use
sim_rev.h
- fixed nested comments
sim_tmxr.c, sim_tmxr.h
- added support for clock co-scheduling
- simplified debug code by using sim_uname
- added support for devices which poll for output on different units
sim_timer.c, sim_timer.h
- added support for clock co-scheduling
- fixed asynchronous clock calibration to smooth out calibration adjustments
- simplified debug code by using sim_uname
- added ability (when running with asynchronous support) to explicitly disable or enable asynchronous timer support.
- changed sim_timer_inst_per_sec to return a double value since the result is always used in a double expression and integer overflow could occur under strange timing conditions
vax/vax_stddev.c
- converted from simulator specific clock co-scheduling to generic clock co-scheduling.
vax/vax_cpu.c
- added EVENT and ACTIVATE debug flag (SET CPU DEBUG=EVENT;ACTIVATE) support
pdp11/pdp11_dz.c
- converted from simulator specific clock co-scheduling to generic clock co-scheduling.
pdp11/pdp11_vh.c
- converted from simulator specific clock co-scheduling to generic clock co-scheduling.
pdp11/pdp11_xq.c
- converted from simulator specific clock co-scheduling to generic clock co-scheduling.
pdp11_dmc.c
- Fixed DMA bug which wrote data into the wrong simulated memory address.
- Fixed incoming IP address checking.
pdp11_io_lib.c
- Added the DMC device to the autoconfigure device table
vax780_defs.h
- Added comment for DMC11
pdp11_xq.c, pdp11_xq.h
- Added emulation and visibility to the LEDs which were on the physical DEQNA/DELQA network boards. "show xq: will now display the LED state in addition to the other useful things.
- Added debugging of loopback packet data
- Avoided padding on short loopback packets
- Added support for extended length loopback packets (up to 1600 bytes) which is described in the DEQNA manual and used by the MicroVAX I boot ROM. Recieve such packets with the LONG error indicator.
- Returned 'reserved' status bits as 1's in received packet status word 1.
- Added debug display of transmit and receive Buffer Descriptor List contents.
sim_ether.c, sim_ether.h
- Added support for extended/oversized packets.
Added support for per line tcp listen ports.
Added support for per line outgoing tcp/telnet connections.
Removed DEV_NET from pdp11_dz and pdp11_vh emulators to allow proper restore of
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
It also modifies the HP 2100 and PDP11 multiplexers to add serial support as demonstrations of the capability that, one day, might be extended to all simulators. I have tested the HP support, but I relied on Holger Veit to test the DEC stuff, so I can't guarantee that it works. I also relied on Holger to test under Linux, so the same caveat applies.
The changes needed in the device simulators are relatively small. For example, if you look at the patches for "hp2100_baci.c", you'll note that most of them are documentation changes. The only things of note are:
- an expansion of the TMXR initializer
- additional code in the "attach" routine to try attaching a serial port
if attaching a socket fails
- additional code in the "detach" routine for the same reasons
The HP MPX device (hp2100_mpx.c) needs a tiny bit of additional support from the ATTACH and DETACH commands. Specifically, SCP was modified to set a flag ("sim_unit_ref") to indicate whether ATTACH MPX or ATTACH MPX0 was done, i.e., to differentiate between a device and a unit attach (recall that SCP treats these as both referring to unit 0). This is needed because the socket attaches (logically) to the device, whereas a serial port attaches to a line. Without this flag, the attach routine cannot differentiate between ATTACH MPX and ATTACH MPX0, as the distinction is lost by the time the VM's attach routine is called. This support isn't needed for the HP MUX device because the socket attaches to a different device than the lines do.
MPX also requires a bit more work due to the capability to mix serial and Telnet lines on the same multiplexer (BACI is a single-line terminal device).
The attached PDF contains revisions to the "Writing a Simulator for the SIMH System" publication that documents the additions and changes to the multiplexer library for serial port support. User documentation for serial port support currently exists only in the initial comments in "sim_tmxr.c"; I will add the appropriate text to the "SIMH User's Guide" if we decide to add this to the release version.
- 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
and data traffic (SET VH DEBUG[=REG;INT;XMT;RCV])
- Added SET LOG and SET NOLOG support for logging mux
traffic
- Fixed SET VH LINES=n to correctly adjust the number
of lines available to be 8, 16, 24, or 32.
- Fixed performance issue avoiding redundant polling in unit
service routine (removed 75% of polling overhead)
pdp11_dz.c: - Added debugging support to trace register, interrupt
and data traffic (SET VH DEBUG[=REG;INT;XMT;RCV])
