The weird stuff I keep finding: 19 bit core memory?

Noel Chiappa jnc at
Wed Oct 21 18:17:45 CDT 2020

    > From: Richard Sheppard

    > There's a piece of core on eBay .. which claims to be H214. The interesting
    > thing is the label says 8K x 16 but the silkscreen says 8K x 19.

DEC did that a lot; used one silkscreen (and etch) for two different modules,
with differing componet sets to produce two different boards (e.g the MSV11-D
and -E:

M8044 and M8045 respectively; the boards all say 'M8045' in the etch, you
have to look at the handles). The H214 is the 16-bit wide version of this
board, used in the MM11-L UNIBUS memory:

The parity MM11-LP uses the H215 (an 18-bit wide version), and a G109 instead
of the G110 (again, same etch, some components left off for the G110.

There's also an H213, used in the MM11-K:

which is an 8KB version; the H213 looks identical to the H214 at first
glance, but if you look closely the core mats are only half as dense.


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