Originally, the VAX allowed immediate operands (8F) to be used without
restrictions in address mode instructions, either standalone or indexed.
Starting with MicroVAX II, immediate indexed became reserved. This
remained true for all subsequent chip implementations. The SRM was
ECOed in March, 1985 to make immediate indexed unpredictable.
In MicroVAX II, immediate g-floating operands didn't work correctly. The
problem was found a couple of months after tape-out. While the index
flows could be fixed, and were fixed according to the microcode revision
history:
; 7-May-84 [RMS] Fixed FD problem in index flows (JLR)
the problem in indexed immediate could only be fixed by a significant
hardware change in an area that was already packed full. The VAX
Architecture Team, which had always been very sympathetic to the
VAX chip efforts, proposed a much simpler solution: make immediate
indexed unpredictable. It was useless, in any case.
I'm rather surprised that this wasn't flagged by the 780 diagnostics.
Maybe it was never tested. It was tested in HCORE (the original MicroVAX I
core diagnostic that is failing), but I removed it subsequently:
; 8-may-85 rms removed indexed immediate tests
Bottom line - the simulator is right for the chip VAXes (including, I think,
V11) and wrong for MicroVAX I and probably the 8600, 780, 750, and 730.
# Conflicts:
# VAX/vax_cpu.c
The makefile now works for Linux and most Unix's. Howevr, 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.
1.2 GRI
- Added support for the GRI-99 processor.
1.3 HP2100
- Added support for the BACI terminal interface.
- Added support for RTE OS/VMA/EMA, SIGNAL, VIS firmware extensions.
1.4 Nova
- Added support for 64KW memory (implemented in third-party CPU's).
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.
2. Bugs Fixed
Please see the revision history on http://simh.trailing-edge.com or
in the source module sim_rev.h.
