On Tue, Jul 16, 2019 at 4:10 PM Mark J. Blair via cctalk <
cctalk at classiccmp.org> wrote:
I've been studying scanned documents for the M9312
UNIBUS
bootstrap/terminator card because of reasons. They refer to Digital
Equipment Corporation Purchase Specifications 23-000A9-01 and 23-000F1-01
for the PROMs, and I'm wondering whether those documents have been
preserved anywhere? I'd love to see them.
Ok, about the reasons: My PDP-11/34A has an M9301-YF bootstrap/terminator
card, which doesn't have bootstrap code for a couple of the newer devices
I'd like to use in the system such as RL02 and emulated TU58. The newer
M9312 card looks more flexible for changing out bootstraps than the M9301
series.
I'm working on getting my hands on an M9312, but I don't know yet whether
I'll be able to get original PROMs for the specific bootstraps that I want.
I haven't identified a trustworthy source for blank old-timey bipolar PROMs
yet (and I'm not sure if I have a suitable device programmer for them), and
I was thinking about making some sort of PROM emulations that I can swap
around like they're going out of style. It would probably be helpful (and
definitely interesting) if I could learn details about the original part
specifications, such as what speed ratings DEC used. I don't have an M9312
in my hands yet, and I'm not yet sure about how rapidly the card performs
its little 4-to-16 bit deserialization stunt.
If 70ns access time parts are sufficient for the M9312's PROMs, then I may
design an emulation with a 5V compatible 28 series EEPROM. If they need to
be faster, then I may need to do something fancier. Or maybe I'll find the
original PROMs that I need and then get distracted and wander off. It may
well be easier to design a replacement for the entire M9312 card than
trying to emulate the individual 512x4 bipolar PROMs, but since when do I
do anything the easy way? I sure wouldn't be playing with 40 year old
computers if I was concerned with practicality and ease of use!
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
Mark,
This guy makes them
https://www.ebay.com/itm/DEC-PDP-11-Boot-Prom-M9312-RL02-RX01-RX02-RK06-07-…
He may be able to advise answers to your questions if you find the price it
too high.
Bill