Andrew Gabriel <andrew.gabr...@oracle.com> wrote:
> If you go back to the late 1970's before tracks had embedded servo data,
> on multi-platter disks you had one surface which contained the head
> positioning servo data, and the drive relied on accurate vertical
> alignment between heads/surfaces to keep on track (and drives could
> head-switch instantly). Around 1980, tracks got too close together for
> this to work anymore, and the servo positioning data was embedded into
> each track itself. The very first drives of this type scanned all the
The first drive I am aware to use embedded servo was the Simemens MegaFile
drive series in 1986 and while it could increase the data density, it caused a
slow down for the head switch time. I was forced to write my own disk
formatting program in order to be able to apply a track skew value != 0 to
compensate this problem.
Fortunately, I did this together with introducing a SCSI generic driver so I
was able to format disks from a running OS and was not forced to boot the Sun
standalone disk formatting program anymore ;-)
Jörg
--
EMail:jo...@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
j...@cs.tu-berlin.de (uni)
joerg.schill...@fokus.fraunhofer.de (work) Blog:
http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily
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