Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!convex!mic!letni!rwsys!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: Adaptec SCSI 2 Support
Message-ID: <283400146@adaptx1>
Date: 16 Jun 91 13:07:23 GMT
References: <31354@hydra.gatech.EDU>
Lines: 25
Nf-ID: #R:hydra.gatech.EDU:31354:adaptx1:283400146:000:1285
Nf-From: adaptx1.UUCP!neese    Jun 15 11:29:00 1991


>/* ---------- "Adaptec SCSI 2 Support" ---------- */
>Do the Adaptec controllers and drivers for Unix support scsi 2 command queing
>and tagged commands? If one connects a scsi 2 device to one of these will it
>be automatically recognized and run in the scsi 2 mode or does one have to
>do something special? How about scsi 2 fast mode 10MB/sec - is this supported?
>Finally does Adaptec have a 32 bit EISA or MCA controller yet? Thanks.

The AHA-1740 EISA adapter, when in enhanced mode, has support for tag queuing.
The recently released ASW-1450 SCO UNIX driver supports tag queuing as well, as
long as the SCSI device supports tag queuing.  The 1740, in enhanced mode,
will also run 10MB/sec, if the device will support it.
The 1542B/1640 (MCA) adapters do not support tag queuing, or 10MB/sec sync
transfers.
All of the adapters, regardless of mode, support on board command queuing.

There is no electrical difference between SCSI-1 and SCSI-2.  There are only
added features/enhancements to SCSI-2.  Only when running faster than 5MB/sec
sync are there any timing differences, but that has to be negotiated for
by both target and initiator.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
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