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From: gnu@hoptoad.uucp (John Gilmore)
Newsgroups: comp.periphs
Subject: Re: Wanted: SCSI Disks for Sun3's
Message-ID: <3132@hoptoad.uucp>
Date: Mon, 5-Oct-87 07:47:16 EDT
Article-I.D.: hoptoad.3132
Posted: Mon Oct  5 07:47:16 1987
Date-Received: Thu, 8-Oct-87 01:41:52 EDT
References: <104400007@datacube>
Organization: Nebula Consultants in San Francisco
Lines: 28

Six months ago I heard from a (technically competent) friend that he'd
tried hooking up a CDC Wren 3 to his Sun-3/50 and it would not work.
However I have recently heard, from someone else, that they were
running four such drives on their 3/50.

When Sun started using SCSI, the only disk controller available that
had decent performance (e.g. 1:1 interleave) and was shipping was the
Adaptec ACB4000, so Sun's SCSI hardware and software were written and
debugged using it.  There was not much experience in the industry with
SCSI and this controller required some funny "manufacturer-specific"
commands to get it to work, e.g. to format the disk, and perhaps to
initialize it at power-up.  Later as Sun (and customers) tried hooking
up other things, they probably ended up generalizing the software; and
the newer SCSI controllers probably require few or no "manufacturer-
specific" commands.

Hooking up SCSI disks is the hardest case because you will want to boot
the system from them, which requires that the boot PROM chips on the
CPU board support your drive.  For most other devices, you can ignore
the device until the kernel is running, and it's easier to write a
kernel device driver than to change the PROM software.

I advise getting the absolute latest boot proms and latest system
release (3.4) from Sun if you want to hook up generic SCSI.  (If you
are on a service contract, I believe this is free.)  Even then, no
promises.  If you succeed, post something to Sun-Spots.
-- 
{dasys1,ncoast,well,sun,ihnp4}!hoptoad!gnu			  gnu@toad.com