7 Nov
2007
7 Nov
'07
9:08 p.m.
On Nov 7, 2007, at 8:19 AM, cctalk-request at classiccmp.org wrote:
Memory for Indigo 2 (IP22) needs to be FPM with ECC.
But I couldn't
find anywhere if these SIMMs may be "registered", aka "buffered".
I see quite a few cheap FPM ECC SIMMs for sale, but most of them have
some strange additional chips on them, I guess that means there are
of the buffered kind. Will these modules work in I2?
FPM 36-bit (often called parity). I have seen on the Internet reports
that the IP22 gangs them together similar to the way DEC does with some
21164 machines to get ECC, but skimming the documentation for the MC1
and DMUX1 doesn't make reference to this, merely "parity". There are
other 72-pin SIMMS (such as the IBM RS/6000 ones) that are ECC, so make
sure that you're not trying to use one of these (ECC uses a different
pinout).
They don't need to be buffered (only 3 banks).
Regarding the Indigo: Indigo R3k uses SGI-proprietary IP12 SIMMS
(shared with the 4D/30 and /35). Indigo R4k has the same memory
controller as IP22 Indigo2, and uses 36-bit 72-pin SIMMs.