Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!udel!princeton!mccc!pjh
From: pjh@mccc.UUCP (Pete Holsberg)
Newsgroups: comp.unix.xenix
Subject: Re: RLL and Xenix (was Re: disk drive hell)
Message-ID: <633@mccc.UUCP>
Date: 10 May 88 15:45:46 GMT
References: <609@mccc.UUCP> <496@megatest.UUCP> <199@turnkey.TCC.COM>
Reply-To: pjh@mccc.UUCP (Pete Holsberg)
Organization: The College On The Other Side of Route 1
Lines: 28

In article <199@turnkey.TCC.COM> jack@turnkey.TCC.COM (Jack F. Vogel) writes:
...  I find it interesting that both of you seem to have performance problems with
...the DTC controller; I am quite sure it is the controller and not the drives.
...We are using two Micropolis drives, one 60 and one 70 Meg (I always forget the
...model numbers) with the WD1003RA controller, this formats out to a shade over
...200Meg. Now we have no DOS partitions so I have not run the Core test, but
...performance empirically seems far improved over MFM.

When I changed the interleave, CORETEST showed that the performance of
the DTC 5280 and Micropolis 1335 were on the money for an ST-506 system.
However, benchmarks that attempt to test realistic situations show this
combo to be fairly slow.  It's not clear that the DTC controller is the
culprit. 

...  I was wondering, how do you have the drives interleaved? Does the DTC have
...a track buffer? The WD controller does not so I set up a 2 to 1 interleave.
...Perhaps running a 1 - 1 is causing the slowdown. Just a thought.

3:1 is required by Microport V/386, but 3:1 is the interleave that shows
the poorer performance.  The DTC controller is fairly inexpensive ($150
and it also controls 2 floppies) so I would be surprised if it had full
track buffering.

...  If anyone out there would like more information or has questions about using
...RLL with SCO just send me some mail and I will be happy to answer whatever
...questions I can.

:-)  What are the model numbers of your Micropolis drives?