Path: utzoo!utgpu!cunews!bnrgate!bwdls61.bnr.ca!bwdls58!mlord
From: mlord@bwdls58.bnr.ca (Mark Lord)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Prestor harddrive controller (anyone got one?)
Message-ID: <5036@bwdls58.UUCP>
Date: 4 Dec 90 17:42:01 GMT
References: <1990Dec4.004838.4624@hub.cs.jmu.edu>
Sender: mlord@bwdls58.UUCP
Reply-To: mlord@bwdls58.bnr.ca (Mark Lord)
Distribution: comp
Organization: Bell-Northern Research, Ottawa, Canada
Lines: 32

In article <1990Dec4.004838.4624@hub.cs.jmu.edu> jmidili@hub.cs.jmu.edu (jeff midili) writes:
<Anyone out there own or use a machine that uses the Prestor hard
<drive controller card?  It's supposed to double the disk space
<of a MFM harddrive.  I assume it uses a compression algorithm on 
<the fly, but I really don't know much about it.  I need another
<drive, but can't really afford one, does anyone have anything
<to say about these controllers?

I have one, it works, and it works well.

It does NOT use compression.  Instead, it simply formats the drive
using a different encoding scheme to put 31 sectors on a track
instead of the usual 17 sectors.   Divide 31 by 17 and you get an 82%
storage increase.  Simple as that.

I use(d) it on a Seagate 251-1, a Miniscribe 3650, and a Priam ???? drive.

Lots of cheap storage space.

The penalties are:   1) most low-level formatters doe not work,
			so you HAVE to use the one that comes with it.
			No big deal, since this is not a frequent need.

		     2) Speed.  The tracks are formatted 3:1 interleave,
			BUT with 31 sectors per track, so the throughput
			is more like 1.5:1, or roughly 317KB/sec.

-- 
 ___Mark S. Lord__________________________________________
| ..uunet!bnrgate!mlord%bmerh724 | Climb Free Or Die (NH) |
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