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

Noel Chiappa jnc at mercury.lcs.mit.edu
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:

  http://gunkies.org/wiki/MSV11-D_MOS_memory

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:

  https://gunkies.org/wiki/MM11-L_core_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:

  https://gunkies.org/wiki/MM11-K_core_memory

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.

	Noel


More information about the cctech mailing list