Having aligned about 25 8" drives over the last 6 months, I can tell you
that if your drive is "eating" your diskettes, the problem isn't with
alignment. If it's damaging your diskette emulsion, it's likely that it's
either missing the headload pad, or the head penetration is misadjusted. I
don't know what the procedure for head penetration adjustment on your
particular drive is, but most drives seem to require a couple of feeler
guages and some glyptol to make sure it doesn't move when you're done.
Before I'll consider LENDING anyone one of my no longer readily available
alignment diskettes, I want to be dead certain it won't be chewed up as
might happen with the misadjusted head penetration or missing headload pad,
or written on as might happen with an inappropriately set-up drive or
controller. Even a $1k deposit won't ensure I get back a thoroughly useable
diskette, and I've not seen one for sale in over 15 years.
Dick
-----Original Message-----
From: John B <dylanb_at_sympatico.ca>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Monday, November 29, 1999 5:38 PM
Subject: Needed: 1 IBM 8" alignment disk.
>Before I find the highest building to jump off of, I though I might ask
here
>first....
>
>I have a Sykes 7150 8" floppy drive (negibus PDP-8I) that I have invested a
>half and hour in and have solved *most* of it's problems... It finally
talks
>to the PDP and I can select tracks, reset, read status, etc... once in a
>while read a sector.
>
>I need a single sided 128 byte record alignment floppy.
>
>When I do a read now, the drive stays busy forever looking for the sector I
>asked it for. (even if the head is on top of it). Since it was made in 1974
>with TTL chips it is only bright enough to sit there and *wait* for the
>correct data to come by. An alignment disk would make life a lot easier.
>
>Anyone have one available? Please e-mail.
>
>P.S. The sooner the better.. this thing is eating original IBM software
>diskettes from the early '70s
>
>
>PDP-8 and other rare mini computers
>
>http://www.pdp8.com
>
>
>
Received on Mon Nov 29 1999 - 19:28:20 GMT