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From: dregis@pldote.intel.com (~Dave Regis)
Newsgroups: comp.sys.ibm.pc
Subject: Re: SCSI hard drive controllers..
Keywords: scsi, hard drive, disk controllers
Message-ID: <51@pldote.intel.com>
Date: 21 Sep 89 20:43:42 GMT
References: <1096@neptune.AMD.COM>
Reply-To: dregis@pldote.UUCP (~Dave Regis)
Distribution: na
Organization: Intel PLDO, Folsom CA
Lines: 44


>suggested that if I change disks I should switch controllers to a pure
>scsi controller.  Claiming addition drives can be daisy chained without
>a problem.  The prices for an 80mb drive and scsi controller were very
>competitive with any other controller.
>
>Any comments or specific experience...


My 386 system is configured with a Seagate ST-01 SCSI controller and
an ST277N disk.  The 277N and 277R mechanisms are the same as far as
I know; obviously the drive controller board is different.  Since
the installation, I've had ZERO problems as far as failures or in-
compatibilities.  

A point to consider:  SCSI drives have two ways of being addressed.
There are hardware jumpers and the is also a software address built
onto the drive.  The drive I have was originally on a Mac and the
software address was set to 3 (three).  When I yannked from the make
and hooked it up the the PC, the ST01 wouldn't see any devices on the
bus (SCSI); the firmware only recognizes devices zero (0) and one (1).
The tricky part is that this drive can be set to be recognized by its
software or hardware address; on my Mac, I use software addresses as
it makes it much easier to reorder the disks.  I fought with the 
darn thing for two weeks twiddling the cable, jumpers, etc, until
the realization hit me.  I then hooked back up to my Mac, set it
for hardware addressing, hooked it up the PC, and WOW it worked.  I
had made several calls to Seagate who claimed the controller must
be bad -- they hadn't suggested the addressing mode!  It probably
won't be an issue unless the drive had been Mac-ed at some time
during its life.

Also:  As delivered, the ST01 (probably ST02), only recognizes the
devices addressed as 0 and 1.  Seagate claims that drivers can be
written to allow upto 7 devices on the bus  -  I've seen it done.

Overall performance has been good.  I don't have any disk benchmarking
programs that give avg seek time and data throughput rate, so I can't
give you any figures.  I can say that it is WAY quicker than the 
ST225(N).

Hope this helps...
Dave Regis
nosig