View Full Version : IBM AT PC HDD Problems (Finally got MS-DOS to work on it...)

June 25th, 2003, 07:07 AM
Well, I finally got MS-DOS to boot up on the old gal, but a new and interesting (also frustrating) problem has arisen.

I started out with two HDD's hooked up, a type 2 and a type 20 (both clearly labelled). No startup/setup errors and it continued into DOS, to which I ran FDISK. Once in FDISK, it alerted me that Disk 1 (second HDD, D:) was not functioning. Nonetheless, I could FDISK both C: drive and D: into DOS Primary partitions. Once out of FDISK, I could format C: drive quite easily, but D: drive was still unaccessable. So, I tried my other HDD's, another type 20, in the D: drive position. Upon startup, my formatted C: drive needed to be partitioned and formatted again, and the D: was still not functioning. If left alone, the C: drive can be used perfectly while the D: is left useless - can save DOS and anything else on C:, and it will still be there on startup, but as soon as you try to do anything to the D: drive, the C: gets wiped, too.

I tried it with only one HDD but I can't connect to it at all. The only way I can work any HDD is by putting in two and leaving the dead D: alone.

Anyone care to help me, please? It's quite frustrating, especially after having installed MS-DOS now 4 times, painfully slow by transferring between other old PC and 8 360K disks, only to have C: wiped clean after each encounter with D: drive.

I suspect that the smaller ribbons on the two HD's may be switched arround in error, but I have no way of knowing which should hook up to what drive, and I would like to hear an opinion before proceeding first.

I would try the controller card out of my second IBM AT, but it appears to be fried - keep getting "Controller Disk Error" on startup... =/

June 25th, 2003, 08:11 AM
I'm pretty sure these old drives still had master/slave jumpers like modern IDE drives. If so, you might have both drives set up as a master which could be causing the problem.

Working from vague memory: Didn't the AT controller have a single connection for each drive rather then a ribbon cable that connected to two drives? If so, I think the second drive required a different cable (one with a twist in it). I may be remembering floppy cables, though, so don't hold me to this. . . I wish I had my AT available for reference.

Speaking of reference, if you're interested I saw this auction (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2738451045&category=4193) this morning for a set of IBM AT manuals and such.

Good luck!


June 25th, 2003, 02:49 PM
I'm pretty sure these old drives still had master/slave jumpers like modern IDE drives. If so, you might have both drives set up as a master which could be causing the problem.That's what I'm beginning to suspect, too. Oh well, atleast I got DOS working on it now, which is another step forward.

Have any ideas where I can get jumper guides for these massive HD's? I doubt it would be easy for drives this old...

June 26th, 2003, 02:35 AM

After checking each drive carefully, each cable connection, I came to the conclusion that it was not a hardware problem, but most likely a -software- problem ("When you have eliminated the impossible, whatever remains, however improbable, must be the truth!" - Sherlock Holmes).

I was trying to correct the HD problems with the only tool I had available at the time FDISK, which I have had the misfortune of using before in the past. Other people swear by it, but I haven't been able to produce any results using this program, on any other computer at all. So, knowing my past track record with that vile piece of partitioning programming, I scooped up a copy of "Disk Manager", recommended for use on older computers - especially those with MFM interfaced drives (Modified Frequency Modulation).

Problem solved, totally! Two perfectly working HD's - one 20MB and one 30MB - both without surface errors, bad clusters, or any other nasty surprises. MS-DOS v6.22 smoothly installed onto C:drive (albeit slowly, having to transfer almost 6MB of data on just a few 360KB floppies, moving back and fourth from my other legacy computer).

With my main mission accomplished now, my next goal is to find DOS drivers for the ethernet card I have installed in it, so I can work on getting it on the Internet! Mwahahaa! :twisted:

Maybe even a sound card... oh! oh! I know! Even a mouse so I can play Silent Hunter on it! Wheeee!

Hehe, thanks to all who have helped me along the way.

*stomps on FDISK*

June 26th, 2003, 05:45 AM

FDisk is a PITA program and, unless you've learned it by force (when it was the only option) you're probably better off finding something better.

The only really good thing about it is that it comes with DOS. . .

Good luck with the build-out!