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23.06.2022, 00:08 Uhr
Escaper
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Hello dear forum dwellers! I hope it's okay if I write in English. I did study German in school, but it was many, many years ago and I don't remember much, unfortunately.
Recently I've become a happy owner of Robotron EC-1834 machine. It was in pretty good condition when I bought it but it did have a few issues (keyboard didn't work, floppy drives worked one time out of ten, etc.). I fixed most of those issues, but now I am facing an issue which doesn't seem to be easily solvable. The operating system does not see the hard drive (Robotron K5504.20).
Here's how the problem manifests itself. I power on the computer. There is a system diskette (DCP DOS 3.30) in floppy drive A:. System starts to boot. At some point during boot-up, the LED on the HDD lights up for a couple of seconds, then it goes out and booting continues. After booting finishes, the operating system does not see the HDD. If I type "c:<Enter>", I get message to the effect "Invalid drive specification" ("Ungültige Laufwerksangabe").
I read somewhere (probably on this same forum) that Robotron hard drives of the era had this issue with oil inside HDD becoming alike rubber with time and preventing the heads and disks from moving. This seems not to be the issue in my case though, as I clearly hear the disks starting to rotate when I power on the machine and the motor moving the heads as well. So, mechanical part seems to be in order. It doesn't seem necessary to me to take the hard drive apart to clean inside.
So, it looks to me like the problem is with the electronical part. Either in the hard drive controller card, or in the hard drive itself, or both. Here's the simple things I tried to exclude them as cause of the problem:
- Checked connectivity in both interface cables between the HDD controller card and the hard drive. They both are okay.
- Read the image of the EPROM chip on the controller card. Its content is totally ok, it matches one of the EC-1834 HDD controller ROM images I found on the web.
- Tried switching jumper connectors on the controller (they define the type and model of the drive). No effect.
- Cleaned the controller card, took out the controller chip out of its socket and put it back in. No effect.
- Removed all extension cards except bare minimum (video, FDD and HDD controllers) to exclude their influence. Still the same.
- Ran HDINIT utility found on the system diskette several times. Mostly, it just errors out saying that the drive OR controller is defective. But one time it did start formatting the drive! It took it around 15 minutes to finish and during that process the motor was clearly moving the heads. However, when the process finished, the program reported that all 615 x 4 = 2460 sectors were bad. So disappointing. And then back to square one -- I cannot switch to drive C: because "Invalid drive specification".
Does any of this ring a bell? At least it would be very helpful to understand where the problem lies--is the hard drive dead, or controller is glitchy, or...
Any help is appreciated!
Dieser Beitrag wurde am 23.06.2022 um 00:43 Uhr von Escaper editiert. |
