Subject: SCSI controller / driver info
To: None <netbsd-current-users@sun-lamp.CS.Berkeley.EDU>
From: Havard Eidnes <>
List: current-users
Date: 01/04/1994 00:30:27

I'm currently considering a SCSI controller card for my EISA based PC.  I
have more than 16MB memory on this PC, which currently only has an IDE
drive.  This means, for the time being, that I need an EISA SCSI controller
and a driver which supports this configuration, i.e. it doesn't use some
"compatibility mode" which seems to be there on some controllers.

I'm also in the situation that I'm "hardware-impaired", i.e. I do not know
very much about PC hardware.

It would be very nice if there was some information in the NetBSD
distribution which in a few lines could summarize the hardware supported
and the state of the drivers, along the lines of

	driver xxx.c	This is the brand xx xxx controller, which
			an ISA-only bus-mastering SCSI controller.

	driver yyy.c	This driver supports the brand yy yyx and yyy
			controllers.  yyx is an ISA-only bus-mastering SCSI
			controller, yyy is an EISA bus-mastering SCSI
			controller which this driver only uses in ISA-bus
			compatibility mode.

	driver zzz.c	This driver supports the brand zz zzz controller,
			which is an EISA bus-mastering SCSI controller,
			which this driver supports in EISA mode.

or something of that sort.  Currently it's somewhat hard to decipher this
information from the *.c driver files...  For example, I found this
"disturbing" comment in the bt742a.c file:

 * bt742a BT-1542A SCSI driver

and very little else that points to what sort of cards (and settings on the
cards?) this driver actually supports.  This sends me off on the following
line of questions:

What's a BT-1542A?  Does BusTek produce one with that number?  Didn't
BusTek use similar numbering to Adaptec's numbering (that was my
perception)?  Isn't Adaptec-1542A an ISA-only controller?  Does this mean
that BusTek 742 is an ISA controller?  Does this mean that this driver
won't work with more than 16MB memory installed (not considering the future
where "generic bounce buffers" may solve this problem for ISA controllers)?
Does this driver support the BusTek 747 (Fast SCSI) and 757 (Fast+Wide)
boards?  What boards does this driver really support?

(This is not only an example, I would very much like to receive the answers
to these specific questions as well.)

As I said, it would be really nice if this sort of information could be
gleaned from some of the accompanying documentation...

- Havard