[Simh] Install of VMS4.6 on VAX 780 crashes

[Jason Stevens]

You didn't build it with -O2 on linux did you?  There is some weird
things with GCC and SIMH's VAX...  I can only speak to 4.X BSD, but I
was able to identify two procedures that when optimized with -O2 break
4BSD on SIMH....

I kind of detailed it here:

http://www.mail-archive.com/simh@trailing-edge.com/msg00463.html

And the procedures in question were:

op_ldpctx
op_mtpr


On Tue, Dec 28, 2010 at 9:50 AM, Peter Allan <petermallan at googlemail.com> wrote:
> Thanks to Mark, Wilm, Greg and Rob for advice and help with my problem.
>
> I have now managed to do the following:
>
> 1) Install VMS 4.6 on an emulated microVAX 3900 on Linux
> 2) Use that system disk on an emulated microVAX 3900 on Windows XP
> 3) Use that system disk on an emulated VAX 780 on Windows XP
> 4) Install VMS 4.6 from scratch on an emulated VAX 780 on Windows XP
>
> BUT
>
> I am still failing to get the 780 emulator to work properly on Linux (CentOS
> 5.5). I tried copying the system disk that worked on Windows XP back to
> Linux, but I get the same problem as below, i.e. it crashes in SWAPPER.
>
> I would be tempted to say that there is a problem with the 780 emulator on
> Linux, except that I successfully installed VMS 7.3 a couple of days ago.
> So, I have made considerable progress (thanks again to those mentioned
> above), but I still cannot get VMS 4.6 running on a 780 on Linux, which was
> my main target.
>
> Any further ideas?
>
> Peter Allan
> On 27 December 2010 11:30, Peter Allan <petermallan at googlemail.com> wrote:
>>
>> I have managed to get hold of some versions of VMS, mostly VMS 4.X and I
>> am trying to install VMS4.6 on an emulated 780 using simh.
>>
>> The sequence I have followed is:
>>
>> Boot using the VMS 7.3 CD
>>
>> Run BACKUP to copy the REQUIRED saveset from the VMS 4.6 emulated tape to
>> an RA81 disk with the command
>>    BACKUP/VERIFY  MTA0:REQUIRED/SAVE  DUA0:
>>
>> However, when I boot from the RA81, expecting the installation sequence to
>> continue, I get
>>
>>    VAX/VMS Version  KG  15-Jun-1987 10:00
>>
>>
>> **** FATAL BUG CHECK, VERSION =  KG  INVEXCEPTN, Exception while above
>> ASTDEL or on interrupt stack
>>
>>     CURRENT PROCESS = SWAPPER
>>
>>     REGISTER DUMP
>>
>>         R0 = 00000008
>>         R1 = 04080000
>>         R2 = 00000000
>>         R3 = 00000000
>>         R4 = 80002748
>>         R5 = 00000000
>>         R6 = 00000000
>>         R7 = 00000000
>>         R8 = 00000000
>>         R9 = 00000000
>>         R10= 00000000
>>         R11= 00000000
>>         AP = 00000000
>>         FP = 00000000
>>         SP = 801F91D0
>>         PC = 80004862
>>         PSL= 04080009
>>
>>     KERNEL/INTERRUPT STACK
>>
>>         801F91D8  00000004
>>         801F91DC  00000000
>>         801F91E0  FFFFFFFD
>>         801F91E4  00000000
>>         801F91E8  00000000
>>         801F91EC  00000001
>>         801F91F0  00000003
>>         801F91F4  00000454
>>         801F91F8  8000A71B
>>         801F91FC  04080000
>>
>> Reboot requested, PC: 80158B91 (HALT)
>>
>>
>> Has anyone any idea what is going wrong?
>>
>> I successfully installed VMS 7.3 from the CD on the 780. Experiments give
>> a similar crash when running VMS 7.3 if I have too little memory on the 780
>> (less than 32MB), but no fiddling with the amount of memory seems to help
>> with VMS 4.6.
>>
>> I think someone out there has VMS 4.6 running, so I trust it is possible
>> and I am doing something silly.
>>
>> Peter Allan
>
>
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