20 Mar
1998
20 Mar
'98
1:20 p.m.
On Thu, 19 Mar 1998, Tony Duell wrote:
Probably more related to track density which is now well in excess of
2000tpi!
- don
donm(a)cts.com
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Don Maslin - Keeper of the Dina-SIG CP/M System Disk Archives
Chairman, Dina-SIG of the San Diego Computer Society
Clinging tenaciously to the trailing edge of technology.
Sysop - Elephant's Graveyard (CP/M) - 619-454-8412
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see old system support at http://www.psyber.com/~tcj
visit the "Unofficial" CP/M Weg site at http://cdl.uta.edu/cpm
with Mirror at http://www.mathcs.emory.edu/~cfs/cpm
Since the late
60's, most servo-writing equipment uses laser interferometers
to lay down the tracks. "Special" certainly *is* the operative word
here!
I'd realised it wasn't a mechanical stepper motor (nowhere near accurate
enough), but I'd not realised that it was a laser interferometer. Ouch!
I'm suprised it has to be _that_ accurate, since surely minor errors in
track position would be compensated for by the servo system of the drive.
But I guess the makers know what they are doing.
Tim.
-tony