21 Oct
2020
21 Oct
'20
5:53 p.m.
My guess is the H215 has two more core fields on it since mine has 3 (18
bits plus parity). Odd they could fit up to 20 bits, maybe an early ECC
(16b+4 ECC?)
C
On 10/21/2020 7:17 PM, Noel Chiappa via cctalk wrote:
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