Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!ucsd!nprdc!malloy
From: malloy@nprdc.arpa (Sean Malloy)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Anyone running RLL on Miniscribe 3650?
Summary: PerStor PS180 ARLL controller works fine
Keywords: RLL, Miniscribe, 3650, Harddisk
Message-ID: <903@skinner.nprdc.arpa>
Date: 20 Sep 88 14:02:20 GMT
References: <461@upvax.UUCP>
Reply-To: malloy@nprdc.arpa (Sean Malloy)
Distribution: na
Organization: Navy Personnel R&D Center, San Diego
Lines: 64

In article <461@upvax.UUCP> stevewa@upvax.UUCP (Steve Ward) writes:
|I've seen notes from time to time suggesting that the media on the
|Miniscribe 3650 is good enough to use as an RLL drive.
|
|Well, I have one of same, and am considering getting an RLL controller
|if it's reasonably reliable when using this drive.
|
|So I'd like to hear from anyone who's tried using the 3650 with RLL
|encoding...I'm interested in reliability, how much storage you ended
|up with, and any difference in speed.
|
|I'd also like reccomendations on controllers...Ideally I'd like to
|get one with the floppy controller on the same board (like WD's),
|since otherwise I'd have to buy a seperate floppy controller.

I've been using my 3650 with a PerStor PS180 ARLL controller for about
three months now, and haven't had any problems with it. I installed the
PS180 right after the July 4 weekend (when I bought the controller, it
had the wrong ROM for my system, and I figured that since I would be
going out to Phoenix for WesterCon over the July 4 weekend, I might as
well drop over to PerStor in Scottsdale and get the ROM swapped,
rather than wait for shipping it each way).

There was no problem formatting it using PerStor's format utility, and
(modulo the two drive defects) gave me a formatted capacity of 38
megabytes, which I've partitioned into two 19 Mb drives. The PerStor
controllers are advertised as being able to be used with _any_ hard
disk, whether it's rated for MFM or RLL, and not quite doubles the
capacity of the hard disk (that's the MFM capacity -- an ST238 running
on a PerStor controller will give 38 Mb, not 57Mb). In fact, all of
the performance information on the paper slipcover around the box are
for the PS180 controller with a 3650 drive.

The PS180 controller is an 8-bit card; as of 7/2/88, PerStor did not
make a 16-bit controller card, although the programmer I talked to
said that one was under development. The throughput using the ARLL
controller was about 10-15% better than my old MFM controller. 

One caution about the PerStor controllers. The ROM release as of
7/2/88 requires that the disk be low-level formatted with PerStor's
format utility. The ROM has a weird translation table for interleave
values, so that calling the 'format track' BIOS routine will not get
you the interleave value you expect. This means that any disk utility
that does a dynamic re-interleave of your hard disk won't work the way
it thinks it does. There is a newer version of the ROM that might be
available now that uses a more intelligent interleave translation to
enable the PS180 to recognize when a single track is being
reformatted, and output the interleave the way the format request is
asking for it, but I don't think that this is currently installed in
the boards that are shipping.

The PS180 controller lists for around $400, but with some shopping
around, you should be able to find a fairly deep discount -- I bought
mine for $225. A good deal, all told -- for less than another 20Mb
drive would cost me, I doubled my disk capacity, and get 2-for-1 on
any other drive I buy. I recommend the PerStor controllers highly.




	Sean Malloy
	Navy Personnel Research & Development Center
	San Diego, CA 92152-6800
	malloy@nprdc.arpa