Why, yes, I do have many Microvax 2000 motherboards.
What numbers do you have on your ROMs? I seem to have a variety of numbers
on various boards. Maybe I can find a match.
----- Original Message -----
From: "Ethan Dicks" <ethan.dicks at gmail.com>
To: <classiccmp at classiccmp.org>
Sent: Tuesday, September 14, 2010 11:05 PM
Subject: MicroVAX 2000 ROM placement question
Hi, All,
I've been trying to dust off a MicroVAX 2000 for VCFmw, and so far,
all I've accomplished is literally getting the dust off.
This unit was one I tried to install the SCSI-enabled patched boot
ROMs in some time back. I _thought_ I had arranged the original ROMs
in the same pattern, but it's possible with all the swapping, I got
some mixed up. I have checked (and re-downloaded) all the ROMs I have
- one factory set (23-092E7-00 through 23-095E7-00) and one patched
set. Cross-checking with the Technical Reference manual
(EK-VTTAA-TM-001) from Bitsavers, I have verified that all ROMs have
reasonable contents in the first few bytes (there are three signature
bytes, among other things). No matter which set I have installed, I
cannot get the console to respond with the self-test info.
Does anyone have a photograph of a KA410 board where the labels on the
ROMs can be read? Alternately, does anyone have any docs with part
numbers? I'm reasonably certain that the underlying hardware is
functional and that I just need to re-install the ROMs correctly.
Yes, I could try the lucky-dip method, but one of the ROMs is rather
difficult to pull (owing to the memory interface connectors), and I'd
rather not break a pin off while sequencing through a dozen chip
swaps. I'd like to _know_ what goes where before I proceed
(especially if I am wrong and I _do_ have a hardware fault).
I don't have any video cables handy, but in case it does come down to
testing with a tube vs a console terminal, I have a four-plane video
interface in addition to the mono frame buffer all KA410s come with.
I had just thought that it would be easy enough to use a BCC08 console
cable and go from there (it's worked before).
Thanks for any tips or pointers,
-ethan
P.S. - I've been delving into the guts of the machine deeply enough
that I'm musing about what it would take to make a 16MB memory board
that didn't respond in the lower 2MB (to work with the on-board
memory). Static would be easy to interface, but the KA410 _does_
generate and pass along refresh signals, so something with 30-pin or
72-pin SIMMs shouldn't be that hard to whip up. I'm only considering
it because my largest memory board is 4MB, and the current prices for
an MS400-CA (12MB DEC board) are more than I'm personally willing to
pay - I'll do without first (which is what I'm already doing ;-)
P.P.S - this would probably all be moot if I had a SCSI-based MicroVAX
slab of some sort, but I just haven't been in the right place at the
right time. Perhaps some DEC gear will make an appearance at the
VCF...