Re: 8280 Drive - Service Manual / FD1797B-02

You're welcome.

They are branded as DS, DD? The original ones I bought on evilbay were 
sold as DS, but were in fact SS. The difference is just a few degrees 
difference in where the index hole is. To answer your PM here, yess - it 
works fine on an 8032 using the 'HEADER' command and no special 
parameters were needed.

When it does format it takes a long time and is a two pass process. On 
the first pass it clicks through at about a track a second and just 
writes 00 to every sector. On the second pass I think I read it scans 
for bad sectors but takes about 10-15 seconds per track. The entire 
process takes around 20 minutes to format a disk. Here's a screenshot I 
had lying around from formatting a 8280 disk from a 610.

http://inchocks.co.uk/commodore/format_disk2.jpg

I seem to remember that even when I got decent disks, it took quite a 
lot of effort to get the drives functional. I replaced a couple of 
transistors, a blown fuse (which can safely be jumpered on the 848-02's, 
they were ommited from later models.) I think a lot of the black axial 
ele-capacitors and the yellow ones around the speed control area were 
out of spec. Nevertheless, given the symptom you describe, i'd also be 
checking the connectors to the sensors, they were a bit grubby on mine.

cheers, Rob


On 24/04/2018 23:03, Francesco Messineo wrote:
> On Tue, Apr 24, 2018 at 10:47 PM, vossi <vossi@ceffy.de> wrote:
>> Thanks to Rob I found the error at the RAM from 2000-2FFF and replaced both
>> 2114.
>> Now the drive has no flash code anymore.
>> I can access to it with my 8032sk.
>> But if I try to format with the header command it always gives me a "bad
>> disk".
>> I tried both drives and different discs (DS, DD, soft sectored).
>> The errorcode says number 26 = write protect - but all disks (some new ones)
>> have no hole = write enabled!
> I would look at the sensors for the write protect hole and see if they
> work and follow the signals until they reach an input
> pin.
> I have never seen a real 8280 of course... just guessing.
>
> Frank
>