Compaq Portable I

[per]

I recently aquired a Compaq Portable I (Thanks a lot QuantumII!). It got version 00005-001 of the motherboard, and the original floppy disk controller and graphics card. It has been upgraded to 256KB of RAM, and there is no co-prosessor. Stamps on the inside dates it around the spring of 1984.

The unit iself looks pretty nice, some small scruff here and there, the unit has for sure been used a LOT. When opened up, two of the plastic tabs that holds the inner metal chassis to the plastic outer chassis are broken (both are on the same side), however, the remaining ones are strong enough to hold the inner chassis in place. There is also a mix of different screws used holding the inner chassis together (I know there should be different types of screws, but in my cause the location of the different kinds of screws are kind of random). there has certanly been somebody who has opened it completely before.

It works, but it reports a 0001 201 memory error every time the machine is started. I located the failing RAM chip, and placed a working chip on top of it. After that, the machine managed to complete POST but since I didn't insert a boot disk, it gives me a diskette error.



So what I have to do is to simply de-solder one broken RAM chip, and solder one other one into it's place. Too bad desoldering multi-pin stuff is a PITA. Maybe I will deattach all thelegs from the chip before I start to de-solder...

 

[MikeS]

Well, if ya can't get it sorted (or someone else has a need or an irresistible urge) I just happen to have a motherboard for one of those, although it's version 000006-001 rev F.

No way to test, but clean and working AFAIK.

 

[tezza]

That's a nice looking machine. I love the green screen displays of these early portables. It's looks like quite a clear screen.

Yes, I had a similar RAM problem develop with my IBM 5051. It was a very similar symptom and fix to yours (details are here).

Good luck with the replacement. It's certainly doable. The important thing is not to rush it. Take your time and be careful. Damaging the circuit board is the greatest risk.

Tez

 

[QuantumII]

Very nice, Per! Duff luck that the broken IC was one of the soldered ones.. What about installing a socket in its place so that replacing it later in case of failure is easier ?

Solder Wick the bad chip out, and you should be fine

Also, Look into the PSU: My other Portable I had an exploding cap (but it still works). It may have happened with this one as well, because it has been in storage for a LONG time.

Most of the dirt on the case is dust, and if you disassemble the whole case and clean everything with Salmiak or JIF. It's going to shine! (My other one did just that

I hope you like the Portable I!

 

[Andrettigto]

Very nice find, I would love to own one. As a collectible, I'd take it first over a 5155. ......But then again I'd still want the 5155, Hyperion, Osborne 1, Kaypro....

 

[per]

I just replaced the memory chip (allthough you don't want to see my soldering-joints), and the system does now boot. I tested it with a lot of my software, I played some fligth simulator, and a round of World Tour Golf.

Suddenly, while I was using a perfectly clean disk I have used in almost all my other systems, I started to get "Sector not found reading drive A" errors. After that, this happened with all my other disks too, and now I can't barely boot anything.

As I used a verified perfectly clean disk when it happened, I don't believe it is dirty R/W heads. It does seek, so it can't be sticky head assembly rails, and the only thing I can think of then is that the belt driving the motor is starting to go bad. What should I do with this?

 

[per]

I turns out that my main boot disk has been corrupted. When I tried to boot it in my XT, It simply couldn't read from drive B. I tried to reformat it with a known good disk, and then it worked fine for a little bit, before completely dying.

I think a little piece of the disk surface migth have fell off when I used it in the Compaq last day, ressulting in the fact that my Compaq can't read any disk, and that the disk I used when it happened has gotten serious corruption afterwards.

 

[per]

I turns out that my main boot disk has been corrupted. When I tried to boot it in my XT, It simply couldn't read from drive B. I tried to reformat it with a known good disk, and then it worked fine for a little bit, before completely dying.

I think a little piece of the disk surface migth have fell off when I used it in the Compaq last day, ressulting in the fact that my Compaq can't read any disk, and that the disk I used when it happened has gotten serious corruption afterwards.

Fixed. The head assembly rails did only need some cleaning/lubricating.

My theory is that some of the head assembly rails had a lot old sticky grease on it, while the rest did not. When I did a read to a place inside the area with a lot old sticky grease, this old sticky grease spread to the entire rail and I would start to get seek errors.

 

[QuantumII]

Great that you got it working

The machine has been unused for what, 20 years ? so sticky lube on the rails is almost expected

Did you clean the case as well ?