M8728 MK11 memory board info?

Noel Chiappa jnc at mercury.lcs.mit.edu
Fri Dec 9 11:06:39 CST 2016

So, does anyone know of any documentation (especially engineering drawings)
for the M8728, which is the 256KB board for the MK11 (originally), also later
useable in the VAX-11/750 and VAX-11/730?

The M8728 and M8750 are in fact the same PCB, with different DRAMs (16K or
64K) and different jumper configurations, and since M8750 prints are extant,
most of the M8728 is documented, but the M8728 also has some discrete
components that the M8750 lacks (I think to produce voltages used by the
earlier DRAMs that the later ones don't).

Yes, I could work this all out by tracing leads, but I'd rather not!

I have produced a table of all the jumper differences, etc and will be
creating a page to document all this, but actual documentation for the M8728
would be helpful.


PS: Does anyone know the formal names for the M8728? The 64KB board, the
M7984, is the MS11-K, but I don't know the one for the larger one (if it was
ever assigned). The M7850 seems to be called the MS750/MS730 (per the prints).

More information about the cctech mailing list