24 Nov
2009
24 Nov
'09
4:38 p.m.
Maybe someone with a spare drive that could be
dismantled and someone
who could create the specific hardware to write analogically the pack,
could create a machine for creating alignment packs?! :o)
It was done before with 5 1/4 disk drives... :oD
Hmm, I was under the impression that the alignment packs had everything
hard-coded as to ensure the alignment went okay.
John.
24 Nov
24 Nov
6:42 p.m.
Maybe someone
with a spare drive that could be dismantled and someone
who could create the specific hardware to write analogically the pack,
could create a machine for creating alignment packs?! :o)
It was done before with 5 1/4 disk drives... :oD
Hmm, I was under the
impression that the alignment packs had everything
hard-coded as to ensure the alignment went okay. 
6:17 p.m.
On Nov 24, 2009, at 10:42 AM, Alexandre Souza - Listas wrote:
Well, I know nothing about DEC alignment packs. BUT I aligned some
hundred of 3 1/2 and 5 1/4 drives during my life, and the alignment
disk was a very simple disk...analog recorded.
Someday, some clever guy just took out a sample of the patterns in
the analogic disk, created a system capable of reproducing it,
modified a 5 1/4 drive for analog recording (used the same head
amplifiers, but with his analog wizardry) and started to create
analog alignment disks for sale. He made a fortune.
I do believe the same can be done with DEC packs. An alignment
pack must be something on the same grounds. And easier to create
than 5 1/4 disks :)
It really depends upon the drive. On RL drives (5MB & 10MB) *any*
good pack can serve as an alignment pack because of the embedded servo
information (oh, floppies don't have that you say?). RL drives are
also *incapable* of writing the servo information which is why a de-
gaussed RL pack is worthless.
On RK drives because there's no servo information, the alignment pack
is written on a reference drive and the tracks are written to a
precise tolerance. This is because the mechanism on the RK drive
"dead reckons" to the track.
On multi-platter pack drives (RK06,7, RP01,2,3,4,5,6, RM03,5, etc) you
not only have to deal with head positioning but because you might have
as many as 14 surfaces, you have to deal with "stack tilt".
Floppies in many cases are the degenerate simple case of alignment.
TTFN - Guy
Maybe someone with a spare drive that could be
dismantled and
someone
who could create the specific hardware to write analogically the
pack,
could create a machine for creating alignment packs?! :o)
It was done before with 5 1/4 disk drives... :oD
Hmm, I was under the impression
that the alignment packs had
everything
hard-coded as to ensure the alignment went okay.
5609
days inactive
5609
days old
3 comments
4 participants
participants (4)
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ball.of.john＠gmail.com -
ggs＠shiresoft.com -
pu1bzz.listas＠gmail.com -
wdonzelli＠gmail.com