Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!bellcore!tness7!texbell!merch!cpe!neese
From: neese@cpe.UUCP
Newsgroups: comp.unix.xenix
Subject: Re: Future Domain SCSI controller for A
Message-ID: <6800055@cpe>
Date: 19 Oct 88 14:23:00 GMT
References: <522@m3.mfci.UUCP>
Lines: 38
Nf-ID: #R:m3.mfci.UUCP:522:cpe:6800055:000:1903
Nf-From: cpe.UUCP!neese    Oct 19 09:23:00 1988


>First, Future Domain sells 2 types of controllers.  One type is a 
>multithread capable controller, the TMC-830/840/880 family.
>The other type is single threaded, the TMC-870 is this type.
>
>Someone claimed that Future Domain controllers on Xenix were slow.  This
>person also said he is using a TMC-870.   He is correct, Xenix with the
>870 is slow, we do not recommend the 870 for use on Xenix or Unix.  It is
>primarily designed to be a low cost DOS product.
>
>The TMC-830/840/880 performance is very very good on Xenix.  Quite on par 
>with the AHA-1540 Adaptec board which has been mentioned in past letters.
>These boards support multi-thread operations, as does the driver.  The driver
>does not have wait loops in it as someone erroneously conjectured.

Isn't it true that all the SCSI arbitration for the Future Domain adapter
is done by software?  I think this is the case, which still translates
to a high CPU overhead for the driver.

>(bunch of text deleted)
>9) Xenix 2.2.4 has the multi fixed disk driver facilities built into it,
>   but this release is only available with Tandy 1000's.

First, 2.2.4 is availbale from SCO to OEM's.  It is currently sold by Tandy
for use on the 4000/4000LX CPU's.  It does support multiple controllers
as will 2.3GT when it becomes available.  
We will be doing some performance comparisons between the AHA-1540 and
Future Domain products under Xenix, and I invite everyone on the net
who is interested, to submit programs that they think best measures
the performance of a system.  I will be glad to post the results of this
when it is done.  Let's say, we will start this 10/28/88.  Anyone who
wants thier program compared to the AHA-1540 and TMC-830/840/880 should
have thier program submitted before 10/28/88.  Let's settle this matter
once and for all.

					Roy Neese
					Tandy Computer Product Engineering
					UUCP@ killer!ninja!cpe!neese