Which Vax is This?

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sat Aug 4 19:46:11 2001

While trying to solve my timing problem with a PDP-11/83 in a BA123 system,
I thought it might be time to try one of the other BA123 boxes I have. It turns
out it had an M7626 CPU inside complete with 3 M7622 memory boards
and the correct 5016743 usual cabinet kit and Ethernet L4 50020061 cabinet
kit with the spaghetti cable harness. The cable to the DSSI cabinet kit was there
as well along with a 5 part cable for the memory (only four in use of course).

One thing I am surprised about is just how few components there are on the
M7662 CPU board. I see 3 inch square chips (2 with heat sinks on top)
and 3 other somewhat smaller square chips (all 3 with heat sinks on top).
There is also what seem to be a 114.285 MHz crystal. Is this correct?
Is this the clock for the VAX CPU?

There was also a few other boards like an RQDX3, a DHV11 and a DMV11.
Each of these had their cabinet kits. Plus what is probably the parallel line printer
M8020 module and its cabinet kit.

While it is possible that I might eventually want to use it in a uVAX, it just
seems too unlikely right now. Anyone interested in a trade? Or want to
buy it?

Otherwise, is there any way that I might be able to use one of these M7622 memory
modules within a PDP-11 as a RAM disk. I remember that Megan Gentry once
set up some old memory in that manner. Since there are three of these boards,
maybe someone is interested in setting up the hardware for a couple of them and
we could share the results by sharing the boards. I suspect that it would be
quite interesting to have a RAM disk of 16 MBytes for a PDP-11. Actually,
I think I have at least a couple of 4 MByte boards as well for a uVAX II, so even
if it is not done with the M7622 boards, maybe with the others. Since the access
to the memory is via the 50-pin cable over the top, any hardware designed for
one such board should probably work on many other types as well.

Sincerely yours,

Jerome Fine
Received on Sat Aug 04 2001 - 19:46:11 BST