5 Feb
2006
5 Feb
'06
10 a.m.
On Sunday 05 February 2006 02:18 am, Gordon JC Pearce wrote:
Roy J. Tellason wrote:
I don't see how it would, since there wasn't typically anything on the inner
end for it to smack against...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
On Saturday 04 February 2006 05:32 pm, Chuck
Guzis wrote:
I'm sure I've mentioned before about the 1541 test and alignment disk we
used to have in a workshop I used to work at...
Basically it had tracks written starting too far out and progressively
moving in until they were too far in. They were, I believe, written
with "worst case" patterns, and possibly a bit "quiet". The first
few
tracks on the disk were written fairly hot so that even if the head was
a bit out, it would still boot.
What would then happen was it would step through the disk a couple of
times, working out how "close" the head was by determining which track
gave the least CRC errors.
Then it would work out which way the head needed to be moved, wind it
back and then smack it off the opposite end stop a few times. Then it
would cycle through its calibration reading again, and repeat until it
was done.
Brutal, but it worked surprisingly well.
Gordon. ...and I've got a couple of 5.25"
floppies where seeking to anything
past about cylinder 84/42 (depending on the drive) will cause the head
to jam, requiring manual intervention to free it.
I used to see this fairly often when I was fixing commodore stuff, the
head on the 1541 would get jammed to the inside, and one would have to
open the case and manually move it out before the drive would work again.