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From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: <12788@xstor.com>
Message-ID: <283400140@adaptx1>
Date: 14 Jun 91 07:36:53 GMT
References: <1123@venice.SEDD.TRW.COM>
Lines: 42
Nf-ID: #R:venice.SEDD.TRW.COM:1123:adaptx1:283400140:000:2107
Nf-From: adaptx1.UUCP!neese    Jun 13 09:53:00 1991


>/* ---------- "Re: <12788@xstor.com>" ---------- */
>In article <283400137@adaptx1> neese@adaptx1.UUCP writes:
>>I wrote SETSCSI just for this purpose.  I put it in a batch file before
>>calling FASTBACK and then call SETSCSI with no arguments afterwards to reset
>
>Roy, can you check me on some empirical observations re SETSCSI?
>
>1.  It looks like (I disassembled it) it uses spin loops to check for timeout
>when talking to the adapter.  This seems to be a problem on a 25MHz 486,
>although there may be an interaction with the next issues.
>
>2.  It looks like SETSCSI conflicts with ASPI4DOS.SYS -- it simply wouldn't
>run reliably unless I removed the device driver.  I suspect that the driver
>was fielding an interrupt that SETSCSI wanted.
>
>Between the two, I can't find a way to make SETSCSI run in my configuration.
>Even if I slow the CPU down and patch the timeout loop to run longer, the
>lack of the device driver is a problem for running Windows, Smartdrive loaded
>high under DOS 5, etc.
>
>Is there another way to solve these problems I've overlooked?

Your observations are correct.  SETSCSI was written quite some time ago (4
years).  In my current reincarnation of all of my programs, I am allowing
them to use the ASPI interface as an option, but there is no way for SETSCSI
to control the hardware (bus on/off) through ASPI.  ASPI is a generic SCSI
command interface.
However, not all is lost.  If you are using the ASPI manager version 2.0 or
later (and it may apply to the older versions as well - I am not a DOS
expert), you can use the command line flag to set the bus on time to 7
micro-seconds (/N7).  Granted, that will set it that way always, but there
is virtually no detectable performance degradation, unless you are using a
very high performance SCSI drive.
SETSCSI is being re-written to use timers instead of loops, but will not
use the ASPI interface.  It is only useable if you do not have the need to
use the ASPI4DOS driver.

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