From owner-freebsd-hackers  Thu Mar  7 11:36:54 1996
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Date: Fri, 8 Mar 1996 06:33:19 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199603071933.GAA04954@godzilla.zeta.org.au>
To: imb@scgt.oz.au, mtaylor@cybernet.com
Subject: Re: Proper FreeBSD news machine
Cc: hackers@freebsd.org
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>This is highly dependent on the motherboard you have to put it in (stating
>the bleeding obvious :-)) .. PCI is better than VESA or EISA is better than
>ISA. Any decent card, Adaptec or BusLogic will do what you need. Note one
>specific exception - a BT445S is of absolutely no benefit at all over a 1542
>through its inability to avoid the use of "bounce-buffers".

According to /sys/i386/isa/bt5xx-445.c, only "OLD bt445s Revision A,B,C,D
(nowired)" have broken 32 bit addressing.  However, /sys/i386/scsi/bt.c
now enables bounce buffering for all bt445s's.  You can still avoid it
by using option BOUNCE_BUFFERS.  Option BOUNCE_BUFFERS also gives unnecessary
bounce buffering for the ultrastor U24F (EISA) and U34F (VLB) controllers
since ultra14f.c always enables bounce buffering in case the system is ISA
or broken.

I think the bt445s is still better than a 1542 because it is a newer design
and is designed for VLB.

Bruce