disk drive parameters

[Rick Farris]

In article <12009 at ccncsu.ColoState.EDU> writes:

> Disk parameters.  Here's a first stab at compiling
> parameters of some common disks.

This is *not* a list of disk drive parameters.  Mostly it's
a list of what to set in your bios to make it work with a
CompuAdd translating controller.

A drives capacity is *competely* specified by the number of
cylinders it has, multiplied by the number of heads,
multiplied by the number of sectors on each cylinder
(track), multiplied by the number of bytes/sector (512).

Simple math shows that the entry for, lets say a Maxtor 4380
(a ~380 MB (unformatted) drive) would yield:

maker drive          cyls hds secs   seek   pre  LZ  WR   type info
Maxtor XT-4380E       306  4   17      ?    128                Compuadd

	capacity = 306 cyls * 4 hds * 17 sectors/track * 512 bytes/sector
	         = 10,653,696 *Bytes*

Likewise, a CDC 94186-383 (a similar 380 MB drive) also
yields about 10 MB.

A quick back-of-the-envelope calculation should have told
that something was wrong. :-)

No, what's been posted is the list of individual
*controller* manufacturers recommended settings for their
*translating* controllers.

By the way, a quite complete list of drive parameters can be
obtained from the Western Digital BBS at 714-756-8176.  It
includes several hundred drives (every drive I've ever
looked up), and has correct descriptions of the drives.


--
Rick Farris  RF Engineering POB M Del Mar, CA 92014  voice (619) 259-6793
rfarris at rfengr.com     ...!ucsd!serene!rfarris      serenity bbs 259-7757