IBM PS/2 P70-386 SIMM needed...+ a couple other things... - test-drb@ccmp.vtda.org

13 Jan 1999

Nope.  No free slot.  The long slot has an IBM 3363 controller in it, and
the other slot won't accept a long cart, because it hits the cooling fan.
Anyone know what the short slot's for?

Yes, I do have the reverence disk.  The P70 has 4 SIMM slots.
///--->>>
                -Jason Willgruber
               (roblwill(a)usaor.net)
                   ICQ#: 1730318
<http://members.tripod.com/general_1>

-----Original Message-----
From: Lawrence LeMay &lt;lemay(a)cs.umn.edu&gt;
To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
Date: Tuesday, August 10, 1999 11:33 AM
Subject: Re: IBM PS/2 P70-386 SIMM needed...+ a couple other things...

...
 > 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
 lwalker(a)interlog.com

I thought that at least one of the PS/2 model 70 motherboard versions came
with 3 simm slots... I dont recall it needing simms in pairs on the
motherboard, though it does use a non-standard, PS/2 style presence
detect.

Does the original poster have a free MCA slot for a ram expansion board?
I have one for a PS/2 model 70, that I assume would work in your system,
assuming you have the reference diskette for your machine.

-Lawrence LeMay