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From: toma@tekgvs.UUCP (Thomas Almy)
Newsgroups: comp.sys.ibm.pc,comp.periphs
Subject: Re: Lot's of questions
Message-ID: <1987@tekgvs.UUCP>
Date: Mon, 5-Jan-87 11:14:09 EST
Article-I.D.: tekgvs.1987
Posted: Mon Jan  5 11:14:09 1987
Date-Received: Tue, 6-Jan-87 18:58:39 EST
References: <9073FIB@PSUVM> <2750@osu-eddie.UUCP> <434@catnip.UUCP> <551@brl-sem.ARPA> <1029@cad.cs.cmu.edu>
Reply-To: toma@tekgvs.UUCP (Thomas Almy)
Organization: Tektronix, Inc., Beaverton, OR.
Lines: 21
Xref: mnetor comp.sys.ibm.pc:802 comp.periphs:101


Well I had to comment on Bernoulli Box performance matter.  I "Beta tested"
both their original 8" 10 Meg drive and 5" 5 Meg drive, and found that the
drive performance depended greatly on the driver code.  I wrote my own drivers
for the drives, and the system was a Compupro S-100 based with a 8 Mhz 8086,
running CP/M-86.

The drives have the rotational latency and seek times of slower hard disks,
but the (voice coil) head positioners are not energized between commands. 
This means that a seek must be performed before each read or write. The servo
positioners seek time is not really that much better for seeking the current
track than it is for seeking across the disk!

Drivers that read and write a single sector at a time run REAL slow, hardly
faster than a floppy, because of those seeks.  When full track buffering is
performed (I buffered several tracks) then the performace is that of a slow
hard disk with full track buffering!  Which, by the way, is much faster than
a fast hard disk without track buffering.

Tom Almy
Tektronix, Inc.