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.
Having run the device code thru XXDP and some other OS's and scenarios
rigorously, a bunch of discrepancies were found, which need to be addressed
by this rather extensive patch.
1. Each unit must implement its own "drive status" register, to be able to
track per-drive errors / conditions correctly;
2. Fixed INT_SET() / INT_CLR() in RPCS write function (wrong order of the "if"
conditions);
3. Some behavior was implemented not exactly how it was expected from the real
hardware, such as:
a. Post-I/O register values in RPDA and RPCA (including the corner case of
pack overflow);
b. I/O stacking, which wasn't mentioned in any available documentation, but
only XXDP listings;
c. RESET/IDLE function must be accepted for a "busy" controller;
d. HOME function must always execute, even when "device ready" is not set
(e.g. when SEEK error detected);
e. SEEK incomplete should not respond with "device ready" (however, the
condition can be cleared by HOME, d.);
f. WLOA-induced write-lock violation wasn't reflected in "device status".
4. Some timing was off so that the device worked "too fast" -- this was fixed
(except for the pathological cases when the races are in the actual test
code, and cannot be logically fixed);
5. WLOA setup command bug was fixed;
6. Added more code comments found per the above peculiarities.
PDP11/pdp11_rq.c re-uses ->filebuf as a sector buffer (under the #defined
name rqxb) and allocates it as such. If an RQ disk is detached and
another attached, this buffer would be lost and the pointer reset to
NULL. sim_disk.c would only allocate the buffer if UNIT_BUFABLE is set,
which means to buffer the whole disk. Since this rightly isn't set on RQ
disks, the pointer would remain NULL and segfaults would ensue. See
open-simh issue 274.
add comment about safe re-use of filebuf
* CMake build infrastructure
The squashed commit that builds and packages releases for the SIMH
simulator suite with CMake, version 3.14 or newer.
See README-CMake.md for documentation.
* VIDEO: Fix bug: vid_ready can be used uninitialized.
* VIDEO: Not all events come with a valid windowID.
* PDP11: Fix NG SET TYPE.
The sense of MATCH_CMD is reversed.
* display: Fix bug in NG display controller.
There should be a separate state for each of the eight displays.
* display: Symbolic constant for number of displays.
This commit extends the existing DUP11/DPV11 support to add support for HDLC framing. There
is no requirement to support bit/byte stuffing, so the aim is simply to encapsulate/decapsulate
the datalink frame provided by the host driver.
DDCMP has been regression tested on VMS, RSX and TOPS20, and the HDLC mode was developed
and tested with VAX/VMS DECnet Phase V, only using the HDLC datalink implementation.
In theory this support is sufficient to allow Phase IV/V P.S.I and even VMS/SNA to be used,
but these remain to be demonstrated.
- Correct RBUF_GETLINE & RBUF_PUTLINE: these are both sensitive to
modeling DHU vs. DHV; the correct bit mask was not generated for DHU.
- Make certain the device presents 16 lines when modeling a DHU.
This commit extends the existing DUP11 support to add simulation for a DPV11 in DDCMP mode.
It has been tested with DECnet-VAX Phase V, which has the only host driver I know of. Note
that you may see a few CRC errors logged with high traffic levels, these are due to a couple of
bugs in the VMS driver, for which I'm looking at developing a patch.
Regression testing has been done on the DUP11 on VMS, RSX and TOPS20, which all seemed to work
as well as previously.
- This involves adding some trailing characters to received DDCMP frames
to meet host driver expectations (simulation then behaves more like a
real synchronous device). 1 SYN is enough for VMS, but RSX needs a few
when there is no abutting frame.
- The VMS driver implements the CRC performance option in section 5.1.2
of the DDCMP spec., and thus relies on receiving a valid character after
the CRC on a received frame.
Coverity flagged one magtape simulator for having fewer case breakouts
than the range of MTSE_x errors, after they were expanded for
MTSE_LEOT (listed as "V4 compatibility") and MTSE_RUNAWAY (for
Dave Bryan's implementation of erase and erase gap).
According to Dave, it turns out that MTSE_RUNAWAY can only be
returned if the magtape simulator supports and implements a density
specification and the ERASE function. The simulators Bob Supnik wrote
don't meet that criteria, so the expanded errors can't be returned.
Simply add a "default" case to the map logic returning SCPE_IERR for
unexpected cases.
These are added based on simple drive geometry and size information
without any parameters for bad block management (not used in simulation
anyway).
Additionally, RF drives connected to Qbus systems via a KFQSA. When
connected this way, EACH drive on the DSSI bus appeared to the attached
Qbus system as a separate MSCP controller to the operating system. This
change does not model that connectivity.
Additional UNITs from 4 up to 254 are replicated from Unit 0.
If the UNIT->uname has already been populated, we could leak memory if
it isn't released before copying from the template UNIT.
