If you're interested in a speed-up, I'm fairly sure a 486DX/2-66 should
drop-in for the current 33mhz CPU, without any additional changes. Doubles
your core speed and adds the math co-processor in one go.
On Mon, Jan 25, 2016 at 12:29 AM, Mark J. Blair <nf6x at nf6x.net> wrote:
To my surprise, I found something just barely old
enough to interest me on
the e-waste pile at work: An IBM PS/2 85 from around 1993 or so. The hard
drive is long gone and it didn't include a keyboard, but it did come with a
model 8516 touch screen display and original mouse. I already had a nice
Model M to plug into it, plus some scsi2sd adapters sitting around waiting
for projects like this one.
I'm new to the PS/2 line, but after some poking around I found images of
the reference and diagnostic disks necessary to set this machine up. I also
found the ADF file needed for the Cabletron ethernet card in it. The
machine has 12M of parity RAM, with one SIMM slot pair still open. It has a
2.88M 3.5" floppy and a 1.2M 5.25" floppy. The 5.25" floppy is a
motor-eject style which I haven't encountered before. This model has a
486SX 33MHz CPU, and the math coprocessor socket is empty. Aside from a
bunch of dust that I cleaned out, it's in pretty nice cosmetic shape. This
particular model was intended for duty as a server.
I've been posting pictures of the machine on Twitter over the last few
days, starting on 1/21/2016:
https://twitter.com/nf6x/media
I replaced the CMOS battery (conveniently, a CR2032 coin cell, available
at the local supermarket), reconfigured the CMOS settings, set up a scsi2sd
as four emulated 512M SCSI hard drives, milled a pair of generic PC hard
drive mounting rails to length for use in a PS/2, and installed MS-DOS 6.22
on it. OS/2 2.0 would probably be more appropriate for this machine, but I
don't have it. I see original OS/2 2.0 boxes in the shrink wrap on eBay,
but eBay and I are seeing other people at this time.
Well, I seem to have it fully working aside from not having suitable
software installed to test out the touch screen and networking card. The
monitor sometimes makes a bit of high-pitch whine which by some miracle I
can still hear. Younger folks might find it objectionable. I wonder if it
would be effective as a child repellant? :) Thankfully, it doesn't seem to
set my dogs to howling.
And now that it is cleaned up and working, I have no clue about what to do
with it! I just didn't want to see it go to the landfill or end up as toxic
dust in some poor guy's lungs in India, so I got permission and then carted
it home. I am not normally interested in PC-family machines, but actual IBM
ones interest me a bit. And the countless ways IBM found to make the PS/2
line incompatible with regular PC lines give me things to bitch about, and
that in turn gives my life purpose. :)
So, would any of y'all like to help me brainstorm about interesting
applications for this vintage heap, or maybe point me towards non-eBay
sources of software that it would like to run?
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/