IBM PS/2 P70-386 SIMM needed...+ a couple other things...

From: Lawrence Walker <>
Date: Tue Aug 10 10:09:06 1999

On 7 Aug 99 at 18:48, Olminkhof wrote:

> >Basically what I meant is banks of two. There's two SIMMS in a bank, with
> 2
> >banks, totaling 4 SIMMS.
> >
> >If you install three 2 MB SIMMS, instead of getting a 6 MB memory reading,
> >you'll get a 4 MB reading and a memory error.
> >
> Nope.
> You'll get a memory error until you run the reference disk. If you have an
> error while running the reference disk then you have the wrong type of
> simms.
> It's not until you get to Pentiums that you need 72pin simms in pairs.
> >///--->>>
> > -Jason Willgruber
> >>
> >>I've never heard of this "sets of 2" stuff on these.
> >>They use the same simms as the desktop model 70 . . ie with presence
> >>detect circuitry.
> >>
> >>Hans
> >>

 TMK most IBMs (as well as Ataris, Macs and NEXT) require matching simms in
pairs, and as well presence detect in the case of MCA. There is a hardware hack
to get around the P.D. on Peter Wendts site. While I have never tried to add a
single simm physically except to expand the onboard memory of my 8580 to 4m
from 2 , IIRC all the docs mention this. I would certainly be delighted if
this were not so. I have an IBM 486 Ambra (non-MCA) which also requires memory
in pairs but doesn't require PD and a single spare non-IBM 8meg which sits
unused because of this limitation. I have an 8570 A-21 desktop (25mhz and 387
co-processor) and other PS2s. There is also a 16 meg max limitation on most of
the PS2s altho there are workarounds for this I understand.

ciao larry

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Received on Tue Aug 10 1999 - 10:09:06 BST

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