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Date: Wed, 23 Apr 1997 17:55:24 -0600
To: Peter Dufault <dufault@hda.com>
From: Brett Glass <brett@lariat.org>
Subject: Re: Yet another Adaptec 2940UW problem :(
Cc: torstenb@ramsey.tb.9715.org, dufault@hda.com, gurney_j@resnet.uoregon.edu,
        hardware@freebsd.org
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At 07:22 PM 4/23/97 -0400, Peter Dufault wrote:

>Right - I believe only the 1542 can do what you want.

According to their Web site, this is a bus mastering *ISA* adapter, which
means you can't transfer data to or from just anyplace in RAM. Does the
target driver use the OS's "bounce buffer" hack, or would I have to work
around this myself?

Also, the adapter is claimed to transfer up to 10 MBps. I know of no ISA
adapter that actually goes this fast! Is there something that uses a faster
bus interface? I'd like to be able to serve data faster, at least for some
transfers.

>You don't configure a
>pt device you configure an "sctarg" device.  Getting a 1542 may be
>a way to prototype.

Well, ultimately, the machine may be replicated a few hundred times, so I'd
like something I could use for "production" as well as prototyping. Is
there a reason (other than the bus interface) that the board might be
unsuited for production application?

If the drivers only support target mode on this one adapter, is there a
register-compatible model from another manufacturer that runs faster, has a
better bus interface, or is perhaps Fast/Wide or Ultra? I know that BusTek
used to have adapters that were register-compatible with Adaptec, but don't
know if they have kept this up in more recent models on faster buses.

--Brett