Re: Disk Drive alignement Tools

["Silicon Sam" <SiliconSam@gmail.com>]

  Man, I aligned quite a number of drives way back when.  Dysan made
alignment discs in both 5.25" and 3.5".  With the alignment discs, a
program to step the drive one track at a time, and an oscilloscope you
could do it.

  Basically the alignment disc had a specially written signal on I
think tracks 14 to 16.  The signal was written by wavering between the
3 tracks, and you would read the resulting sine wave created on track
15.  Those disks were $50 each, and I either wore out a number of them,
or accidently wrote to them and messed them up.  If you had a faulty
write circuit on a drive, you could write to a write-protected disk.
And no, the disks were not copyable.

  They came in single and double sided.  The fun part was taking a
double sided Mac floppy and aligning the top head to the bottom head.
Doable, but a pain.  it was fun, and I made lots of money fixing
floppies, but them days are gone now....

Raymond