[Simh] VAX 780 emulation - How to install Netbsd

[Johnny Billquist]

On 2014-12-28 18:59, Mark Pizzolato - Info Comm wrote:
> On Sunday, December 28, 2014 at 9:48 AM, Johnny Billquist wrote:
>> On 2014-12-28 18:02, Anders Magnusson wrote:
>>> But; when this was done virtually no big VAXen were still running, so
>>> the support for them may have bit-rotten.  This is what Johnny always
>>> encounters when he tries to power up his 8600 ;-)
>>
>> Heh... Yes, which is why I also keep a copy of boot on the RL02...
>> But booting of my 8650 usually works fine, using VMB. But since I don't
>> often upgrade boot blocks, things occasionally are messed up in current
>> without me noticing.
>> Things have become easier to spot since simh added support for the 86x0
>> machine, as I occasionally try more odd things that way.
>>
>> Note that NetBSD will not boot on an 86x0 machine with more than 64MB of
>> memory at the moment. Something broken that I have not had time to look
>> at.
>
> Calvin Miracle also noticed that the VAX780 had an issue booting/running NetBSD 6.1.5 with some devices when the system had more than 64MB of memory.  Maybe this is the same problem:

Very likely.

>>    More than 64M main memory appears to make RQ undetectable. NetBSD needs
>>        to be initially installed to RQ disks. RP disks are detected, but
>>        cause a panic under fdisk. ;   More than 64M main memory appears to make RQ undetectable. NetBSD needs
>>        to be initially installed to RQ disks. RP disks are detected, but
>>        cause a panic under fdisk.
>
> Please let us know...

Yes. That sounds like the same problem. But this is a NetBSD-specific 
problem. VMS boots fine under simh with more memory configured.

>>> So; bottom line:  If installing NetBSD on a non-MicroVAX machine, it
>>> is a safe bet to put the boot program on console media :-)
>>
>> Agreed. It helps. But it also required that you know a bit more of how you do
>> what...
>>
>> Also, if booting older machines using VMB, you need to know the magic bits
>> of R5, since it requires the same treatment as Ultrix. R5=0 will not boot
>> NetBSD (or Ultrix).
>
> With the latest simh version (and the VMB.EXE it contains) an R5=0 boot will work fine for both NetBSD and Ultrix on all the older VAX models.

Yes. (But I prefer posting information that works right both in simh and 
on real hardware, when possible...)

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol