Looking for schematics for DEC M702 and M720 modules

From: Ethan Dicks <erd_6502_at_yahoo.com>
Date: Mon Jun 9 14:09:00 2003

Both of these are likely to be labelled "memory detection". I have
seen both appear in module listings (and, from reports, in the real
world) in slot B10 of a PDP-8/i. I keep entertaining delusions that
I will be able to upgrade my -8/i to 8K someday. This module is the
only one that I cannot borrow from another machine or my pile of spare
parts.

ISTR the M702 contains a delay line and some buffering TTL. I'm told
that the M720 contains some TTL chips and a few transistors.

My goal is to understand them well enough to fabricate a substitute,
either from scratch, or by co-opting some blank spaces near slot B10 and
using DEC M-series modules.

Thanks,

-ethan
Received on Mon Jun 09 2003 - 14:09:00 BST