Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!evax!utacfd!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: SCSI & RLL:  compatible?
Message-ID: <284500015@adaptx1>
Date: 2 Mar 91 17:27:41 GMT
References: <1420@lehi3b15.csee.Lehigh.EDU>
Lines: 36
Nf-ID: #R:lehi3b15.csee.Lehigh.EDU:1420:adaptx1:284500015:000:1986
Nf-From: adaptx1.UUCP!neese    Mar  1 09:32:00 1991


>/* ---------- "Re: SCSI & RLL:  compatible?" ---------- */
>>In article <7yy0w2w163w@brainiac.raidernet.com> sophist@brainiac.raidernet.com (Phillip McReynolds) writes:
>>>Is it possible to have both an RLL drive+controller & a SCSI
>>>drive+controller inhabiting the same machine?  If it *is* possible, are
>>>there any problems which might make such a scheme either troublesome or
>>>unreliable?
>
>    I would advise against it.  I just spent the last month in that situation.
>  I was running a 65meg RLL drive.  (The drive is actually a 42meg Miniscribe
>3650 MFM that was formatted RLL by the company I bought the computer from.
>  Cheapwads!)
>    Anyway, I bought an 85meg SCSI (ST 296, I think) and an ST01 controller.
>  About half of the time, both worked. The other half of the time, one or
>both of the drives wouldn't work AT ALL.  It was completely random.  A disk
>crash made me do a low-level format on the 65meg RLL, and from then on it
>would only Low level format to 42 megs, no matter what I tried.  Also,
>strangely enough,  about 45% of the time, the drive would not boot (I tried
>both the SCSI and RLL as boot drives) from a coldboot:  A warm boot, however,
>worked fine!  Weird!
>    I tested each drive alone in the computer, and both worked 100% correctly.
>  Something in the interaction was fouling things up, but, like I said, only
>randomly.
>     This has been my experience with a SCSI/RLL duo.  I hope you have better
>luck.  I too, before I started, was assure by Segate and Miniscribe and various
>dealers that there would be no problem....

The problem is with the ST0x adapter.  The 154x adapter has never had any such
problem co-existing with another disk controller (MFM/RLL/ESDI) in the system.
The only reason I mention it is the way you presented the problems you
experienced.  It is not a global SCSI problem.  No flame intended, just want
to be accurate.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex