Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucsd!nprdc!malloy
From: malloy@nprdc.arpa (Sean Malloy)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: PERSTOR Controller Review (ADRT = 190% !!)
Message-ID: <9177@skinner.nprdc.arpa>
Date: 21 Aug 90 15:48:22 GMT
References: <3949@bwdls58.UUCP>
Reply-To: malloy@nprdc.arpa (Sean Malloy)
Organization: Navy Personnel R&D Center, San Diego
Lines: 42

In article <3949@bwdls58.UUCP> mlord@bwdls58.UUCP (Mark Lord) writes:
>The drive is transparent to most software I have.  The exceptions are mostly
>due to software not coping well with DOS 4.01 and large partitions.
>The only real differences are:
>
>	Norton 4.5 "FR" - the Format Recover option does not work.
>
>	PCKWIK Cache	- Does not cope well with the tracks marked as "bad".

Most low-level disk utilities will not work correctly with the PerStor
controllers, probably because they are not set up to handle 31-sector
tracks. For example, IAU, a program that will re-interleave your hard
disk for best performance with the data in place, will hum along
thinking it's working, but _will_ trash the disk. Fortunately, when I
did this, I had taken the precaution of making a brand new backup just
before I started.


>Another difference I noticed, is that the Perstor controller does not do
>track buffering, which makes low interleave values impossible for those of
>us using 8Mhz ISA busses (my cpu is an 18Mhz 386sx).  This means nearly
>anybody who buys one is stuck with 3:1 interleave.  

Equally bizarre, on my 25 MHz 80386, the formatting software would not
work until I switched the machine from 25 MHz to 12 (I think that's
the slow speed) -- it just gave one bad track after another. Slowing
the machine down made the formatting run just fine.

>	4) It is cheap!  I have 147Meg (formatted) for le$$ than a big drive.

It becomes cost effective when you have a) more than 1 drive, b) an
MFM drive 40 Mb or larger, or c) an RLL drive of 80 Mb or larger. If
you have two drives, it's always going to be cheaper than adding
another drive. If you have one MFM drive smaller than 40 Mb, it's not
really cost effective, nor is it for a 66 Mb RLL drive, but once you
get past those breakpoints, it's all gravy.


 Sean Malloy                                   | "The Crystal Wind is the
 Navy Personnel Research & Development Center  | Storm, and the Storm is Data,
 San Diego, CA 92152-6800                      | and the Data is Life."
 malloy@nprdc.navy.mil                         | -- _Emerald Eyes_, D.K. Moran