Commodore PET 8050 FDD problem

[ppieczul]

Hi,

I continue my adventure with PET 3032 and now it is time to get 8050 drive working.
I finally got a cable, connected it and bought some old but new and never used DD floppies. The drive seems to initialize correctly - it ends up with center green led on.

I tried formatting the disk and got of course into a following problem:

• the drive spins up, the head moves several times a tiny bit in both directions, then it moves all the way out to the edge, motor buzzes, head moves to around a center, stops and center led goes red.
• the error code read after that is 20 - read error
• this behavior happens also without a disk (shouldn't it detect there is no disk and do nothing? disk presence switch works fine, as it spins for a while after inserting a disk)
• this behavior is the same on both drives

I recorded a video of this. Please help me diagnose this problem. Thanks.
Pawel

 

[iz8dwf]

Hi,
first of all try to get the complete error, it should be error code (20), error text, track and sector. T,S part is important when a format fails.
There's no "disk presence" sensor. The spindle start momentarily when it senses a change in the write protect sensor. It can't tell if you inserted a disk or removed one.

The command you use for formatting is wrong: it should be "N0:LABEL,ID", not :ID, with the second : it just tries to rename an already formatted disk (and yours isn't formatted).
Frank IZ8DWF

 

[ppieczul]

Ahhh, I was looking for so long at the user manual and my mind just replaced this comma with a semicolon.
It did the trick indeed, the disk formatted and is readable.
Thanks a lot for your help, I feel ashamed for such a stupid error on my side.

 

[iz8dwf]

Ahhh, I was looking for so long at the user manual and my mind just replaced this comma with a semicolon.
It did the trick indeed, the disk formatted and is readable.
Thanks a lot for your help, I feel ashamed for such a stupid error on my side.

I'm glad it was so easy. The most important thing is having "fixed" the problem, not really how you fixed rait

Best regards
Frank