From: Adam Goldberg (adam@microware.com)
Date: 08/19/92


From: adam@microware.com (Adam Goldberg)
Subject: Re: SCSI drivers
Date: Wed, 19 Aug 1992 14:41:00 GMT

drew@ophelia.cs.colorado.edu (Drew Eckhardt) writes:

>In article <1992Aug15.195737.20833@aoa.aoa.utc.com> moose@aoa.aoa.utc.com (Bruce Trvalik) writes:
>>I've checked most of the FAQ's but I have not seen any information on drivers
>>for the Adaptec SCSI 1522 adaptor for one of the "low" cost PC unixes. Does a
>>driver exist?

>No.

>>how hard would it be to port one?

>Port implies that one exists for some other platform, to my knowledge there
>is no freely available driver source for the 1522.

>You'll have to write a lowlevel driver to control the 1522, and will
>probably be drafted to fix it when version 2 of the SCSI drivers are
>finished and debugged, which will happen when I'm less busy and
>otherwise "RSN".

>As far as difficulty : Not as easy as a nifty-whiz-bang intelligent
>board, but not as bad as with the Seagate which only handles half of
>handshaking and arbitration for you, and only interrupts on the SEL
>received when you RESELECT.

>[...]

>I don't know very much about the Adaptec product line, and would
>suggest that you get docs from some one on the board, and then decide
>how much trouble it will be for you.

The aha1522 is more similar to the ST-01/2 than the 1542. The 1522 doesn't
have the on-board SCSI logic that the 1542 has...in fact, you could (or
should) call the 1542 a SCSI controller, and a 1522 a SCSI host adaptor.
The 1522 (to the best of my understanding) gives you access to the SCSI
bus that that's about it. The 1542 does the disconnect/connect, some
arbitration etc for you. Much better.

So: The 1522 driver would be non-trivial.

-- 
Adam G.
adamg@microware.com, or ...!uunet!mcrware!adamg
The above is not to be construed in any way as the official or unofficial
statements of Microware, or any Microware employees.