1 Feb
2006
1 Feb
'06
3:40 a.m.
A 1M 30 pin ZIMM has 1048576 locations each of 9 bits.
A 4M 72 pin SIMM has 1048576 locations each of 36
bits. It's
electrically much the same a 4 20 pin SIMMs. I suspect the adapter
is just connectors wired together in the right way.
I believe so too, both because visual inspection indicates that they
appear to be made of nothing but sockets, etch runs, and a very few
surface-mount passives, and because I once did some experiments and
found that a partially-populated adapter appeared as 32-bit words of
memory of which some subset of the bits acted unimplemented (writes
ignored, reads return all-0 or all-1, I forget which), the subset
depending on which sockets were populated. (The adapter I was testing
with put one byte in each sub-SIMM, but of course there's no reason the
subsets have to be grouped like that.)
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B