Speaking of PS/2s...

From: jpero_at_sympatico.ca <(jpero_at_sympatico.ca)>
Date: Tue Dec 18 19:58:50 2001

> Date: Wed, 19 Dec 2001 00:08:21 -0600 (CST)
> From: Tothwolf <tothwolf_at_concentric.net>
> To: Classic Computers <classiccmp_at_classiccmp.org>
> Subject: Re: Speaking of PS/2s...
> Reply-to: classiccmp_at_classiccmp.org

> On Tue, 18 Dec 2001, Doc Shipley wrote:
>
> > I have a 5870-121 that I snarked recently, with 4 megs of RAM and a
> > 120M ESDI drive. I'm wondering what I want to put on it as OS. I have
> > plenty of Linux/NetBSD critters. I was thinking OS/2, but I threw v3.0
> > Warp on Saturday night, but it's slow as dirt with 4 megs. Oh, yeah. It
> > had the original reference disk in the floppy drive. I think that's
> > really why I bought it.
>
> Are you sure the drive is ESDI? I think the model 70 shipped with an IDE
> drive.

Correct plug into riser from rear where FD drives plugs from front.
It is MCA drive. Very few got upgraded with SCSI MCA card or peecee
IDE card and HD put in. The orignal MCA drives is small, slooow and
usually dead. Hence mine has SCSI stuff put in.

> > Main questions are, how uncommon are they (I know how cool they are),
> > is either one worth anything, and is there a contemporary Unix that'll
> > run on the model 70? Um, that's actually available I mean. All I need is
> > another Ultrix quest.

70'ers worth very little, 5 or 10 each complete as is. Real gems
are A or B models. A is 386dx25 w/ 32K cache, 4 slot 72pin, B is
486DX-25 on same mainboard as A. eg: 8570-Axx or -Bxx look on black
label on rear and on front near base thru a small window. Rarer
still, may have either IBM or reply upgrade board installed aka
peecee in a '70er. Whooo!

If you have bunch of IBM 2MB 85ns simms, chips is same for 2MB 80ns
simms, only move a resistor jumper to empty pads to convert 85 into
80ns simms for A and B series, and few other models that requires
80ns simms. I do that to all of my 2MB simms.

> If I remember correctly, the 8514/A adapter needed an 8514 monitor to do
> anything more than 640x480x16 since it used odd frequencies. Maybe a
> multisync will work if the sense pins are jumpered correctly on the DB-15?

Any clone multisync monitors worth their salt can sync to that I
1024x768 that 8514/A puts out. Reason for using newer monitors
is that 8514 is heavy, bit bulky and usually dim (they were made in
1987-1988 era), only works at 640x480 _at_60Hz and shimmering, blurry
1024x768. Do not buy 8513, they always require new fly even they
works, focus output on flyback always fails.

Be prepared to rebuild IBM FD w/ new capacitors and relube the lead
screw and it's bearing. Mine was gummed up. Compatiable 44pin edge
connector FDs fits across 50, 50z, all 70 and many 80. Only
difference is different bezels depending on different brands of FDs.
These bezels snaps off by pressing on barbs from rear, no, they only
fit 50, 50z and 70 only. Other bezels for 80, 65 60 doesn't fit
other models.

> -Toth

Wizard True blue of 70-A and P75 needs screen debugged, and small
slew of Macs: 475, LCIII+, IIci and empty IIci hacked up box, 8500
and parts of other models. Newer three AMD clones two socket As and
slot A.
Received on Tue Dec 18 2001 - 19:58:50 GMT