8 Jan
2009
8 Jan
'09
12:25 a.m.
Hi Brad!
Topic drift, but your post reminded me of one of the most interesting uses for a VAX I
know of.
Back when HP was developing PA-RISC (mid-1980's) to replace the 16-bit stack
architecture 3000 we used a VAX-750 running BSD to host a PA-RISC simulator. I was working
on the MPE boot-strap code at the time and used the simulator to write in PA-RISC
assembler (no HLL compiler yet) and run tests. We had one 750 for the entire MPE OS Lab,
although only a few of us were using it. Not surprising that the turn-around for compiles
and debugging reminded me of mainframe batch turn-arounds from school, at the end of the
semester of course. Barely usable.
We soon got proto-type CPUs implemented in TTL that plugged into the back-plane of a very
heavily hacked Series 44 (desk form-factor 3000). That way we could have hardware'ish
speed and use real peripherals. Huge improvement before we got real prototype hardware to
do OS bring-up on.
Of course this was all very hush-hush at the time since HP was locked in a death struggle
with DEC in the mini-computer market. Would have been bad press for it to get out that HP
used DEC computers to design its new 32-bit computer architecture.
Cheers,
Lee Courtney
--- On Wed, 1/7/09, Brad Parker <brad at heeltoe.com> wrote:
From: Brad Parker <brad at heeltoe.com>
Subject: got netbsd 2.0.3 to boot on 11/730 in sim
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Date: Wednesday, January 7, 2009, 9:38 AM
The vax unix nerds on the list might find this mildly
interesting:
I hacked a copy of simh vax780 to look like a vax 11/730.
I made a
modified version of the standalone netbsd "boot"
program which does nfs
loads from a deuna (it will do copy's too, which is
handy at times)
With that I finished debugging netbsd 2.0.3 on the 730.
I've gotten it
to boot to a shell prompt on a simh 11/730 with 4mb of
memory using an
nfs root. woo hoo!
So, next I'll make a disk image and put my unibus scsi
card in my real
730 and debug that. With any luck it will just work.
Once it's going on real hardware I'll get it going
on the latest netbsd
(4.0?) and get a patch back to the netbsd/vax maintainer.
[for those who care, I use a linux program which simulates
the tu58 to
boot my 730. I made a boot tape image with putr which
contains the
netbsd boot program (as well as the other files needed to
load
microcode, etc). I plan to spend some time and make a
linux program
which will put together valid tu58 tape images, just to
make my life
easier, since putr requires DOS.]
I have to give the netbsd folks a lot of credit. Their
posix build
system is very handy. But note that releases before 2.0.3
will *NOT*
build on a posix machine - they require native netbsd to
build cleanly.
I've always had a soft spot for the 730; maybe because
the 780 was
just too damn big! :-)
-brad