[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: anyone know where I can find a service manual for Disk II



Silicon Sam wrote:
On Apr 9, 6:26 pm, Mike Willegal <m...@willegal.net> wrote:

Hi Michael,

       Are you sure about the analog recording thing?  I was speculating that
whole track was simply written with some repeating pattern like 1s and
0s.  Last night I was looking at the signals coming from a regular
formatted disk  and it shows many of the same patterns that are seen in
service manual, with a lot of added noise and jitter. I figure that the
noise and jitter came from the sector headers and actual data not being
a consistantly repeating pattern.

Regards,
Mike Willegal

Michael J. Mahon wrote:

Mike Willegal wrote:

Hi Tom,

Perfect,  just need to find or make a good alignment diskette.

Finding may be easier--it's an analog recording!

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."


 The cats-eye signal was written on a floppy by a machine that had a
wobble between tracks 15 and 17 (or whatever two tracks) and that way
you had a perfect sine wave on your scope on track 16.  As I recall
Dysan charged $50 each for them floppies back in the late 70's early
80's.  I wore out and messed up a few of them.

That sounds different than the alignment patterns I saw--
maybe there were multiple approaches...

How fast was the "wobble"?

-michael

NadaPong: Network game demo for Apple II computers!
Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."