Troubleshooting an IBM 5155 - (portable personal computer)

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Jan 19 17:52:44 2005

['scope]
> I'll see if anyone in the local radio club has any I could borrow for a few
> evenings. I know how to use one, it's just been a few years. I have an old
> Heathkit scope behind me, but there's another thing waiting for my
> attention. The trace is about as wide as my pinky and as noisy as heck. Not
> real helpful I'm afraid.

Ah yes... Some Heathkits are prone to that. It's either a changed
resistor in the EHT divider chain, an internal leak in the CRT, or a leak
in the mains transformer (I've come across all 3 faults...) You pray it's
the first one, of course.

[...]

> What is the general opinion on adding an HD to this machine (if it will even
> work)? I've got plenty of ST-406/ST-512 interface drives and controllers for
> 8 bit machines. Of course I only want this for show and tell, so it is not a
> requirement.

IBM never supported a hard drive in this machine, but that doesn't mean
it won't work. As it's a stock XT motherboard with the standard BIOS,
electronically (and with the firmware) there's no problem. The only
problem is getting it all to fit.

IO bought my 5155 (second-hand, of course) with a half-height 5.25"
Winchester in one of the drive bays, cableed to a half-length controller
card in one of the slots. It worked fine, but as I wanted to make the
machine as near original as possible, I removed it, and fitted a real
'IBM' Qume floppy drive. That hard drive has now been recycled (don't
panic, I mean it's gone into some other machine, probably not even a PC,
that neede an ST506 drive).

Another option that certainly works is to use the IBM 5161 expansion
cabinet. You have to put the extended board in slot 2 of the 5155, since
that's the only one it will physcially fit in. You then put a hard disk
controller in the expansio unit, and hae 2 full-height bays for the
drives. The only problem is finding a complete 5161 with the extender
card and the cable.

I suppose (although I have never tried it) that a hardcard would go in
slot 2 also.

-tony
Received on Wed Jan 19 2005 - 17:52:44 GMT