Commodore.ca: The PET, VIC, 128, 64 & More Forum

I just purchased a Commodore CBM 8050 duel disk drive. When connected to my CBM 8032, all three status lights on the drive unit come on and stay on. The three lights are all constant red.

I tried accessing the disk error channels and got the following:
DS=10
ST=3
I also tried the following error channel program and got nothing:
1 OPEN 1,8,15
2 INPUT#1,A$,B$,C$,D$
3 PRINT A$,B$,C$,D$
(this program was in a Commodore refrence manual)

When the disk drive latches are down, the disk motor spins, so the drives themeselves are working. My belief is that the disk drive is not getting commands from the computer and probably has some type of chip damage.
Can anyone tell me what is wrong and how to fix it? Any help would be greatly appreciated!

Thanks,

Mark

Personable85 wrote:I just purchased a Commodore CBM 8050 duel disk drive.

Sorry to "nit-pick".... But I think you mean "8050 *DUAL* disk drive".... not *DUEL*. That is, unless you have a disk drive that's designed for fighting.

-Andrew

Thanks. I stand corrected. My private school education failed me...

Try Zimmers.net. They have alot of diagnostic articles for almost every Commodore product. Sounds like a 6502 may be bad.

Thanks for the information about the Zimmers.com website. I went there and found a repair manual for the CBM 8050 disk drive. The manual stated that the likely cause of the problem was indeed a faulty 6502 chip. I replaced the chip with another 6502 chip I had available, but it made no difference. The problem with the disk drive unit still persists. Unfortunately, I could not verify before hand if the 6502 chip I used to replace the existing 6502 chip in the drive actually worked or not. I may have replaced a bad chip with a bad chip. When I come across another 6502 chip in the future, I'll try to make the repair again. In the meantime, if anyone has any more suggestions, I'm open to them. Thanks again for the help.

Mark

What does the drive do when not connected? I might also suspect a bad IEEE cable, or one that is plugged in upside down on the computer end...

Steve

I put the unit back in the attic for now, but I believe it did the same thing either plugged into the computer or not. All three red disk drive lights came on and stayed on. The IEEE cable is in excellent condition and I verified several times that it was properly connected. I don't know what else to try. The 6502 chip could still be the problem.
Thanks!
Mark