Path: utzoo!attcan!uunet!mcsun!ukc!harrier.ukc.ac.uk!zodiac.ukc.ac.uk!cur022
From: cur022@zodiac.ukc.ac.uk (Bob Eager)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Info wanted on IBM Portable
Message-ID: <21058.272d4b34@zodiac.ukc.ac.uk>
Date: 30 Oct 90 09:43:16 GMT
References: <3643@idunno.Princeton.EDU>
Organization: Computing Lab, University of Kent at Canterbury, UK.
Lines: 38

In article <3643@idunno.Princeton.EDU>, zimerman@phoenix.Princeton.EDU (Jacob Ben-david Zimmerman) writes:
> Hi!  I have managed to recently acquire an IBM Portable Personal
> Computer.  This is an old (i guess) 8088 machine...

Yes, it's a 4.77MHz 8088.

> 1) It has 256K at the moment.  Can I/How might I amp its memory, say to
> 640K?

It has a standard XT motherboard and is therefore upgradeable. The details
have been posted often on the net; let me know if you want them. You need a
decoder chip (about $1.50) and 18 256K memory chips and 1/2 inch of wire.

> 2) It currently has 2 5.25" 360K floppies in it.  Can I put a HD in it?
> Do I need a controller?  What kind of controller/drive?

You'll need a HD controller if you plan to replace a floppy. The power supply
is not quite as beefy as that for a standard XT; a hardcard might be better
although there is only the width of one slot in which to place it. A low
consumption half height drive would work OK, and if you want a HD controller
you might want to consider a short one to leave the full length slot clear.
Or, get a combined controller (warning: the existing floppy controller sits
in a slot that is about 7/8 the length of the normal one).

> 3) Could I simply yank the motherboard and stick in some sort of 286 or
> 386 motherboard, or will they not work with this machine?  

Given that you understand the power supply problems, I don't see why not.
You would need to replace the display and drive controller cards unless the
new board can drive them at the old clock speed. You would also need to
consider the precise location of the slots on the new card (look inside and
you'll see how tight the space is).
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Bob Eager            | University of Kent at Canterbury
rde@ukc.ac.uk        | +44 227 764000 ext 7589
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