Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!ames!ucbcad!ucbvax!decvax!decwrl!sun!texsun!smu!trsvax!authorplaceholder
From: uhclem@trsvax.UUCP
Newsgroups: comp.sys.tandy
Subject: Re: Is SCSI availible for the 16?
Message-ID: <193300013@trsvax>
Date: Sat, 16-May-87 13:04:00 EDT
Article-I.D.: trsvax.193300013
Posted: Sat May 16 13:04:00 1987
Date-Received: Sat, 23-May-87 19:22:43 EDT
References: <5928@shemp.UCLA.EDU>
Lines: 42
Nf-ID: #R:shemp.UCLA.EDU:5928:trsvax:193300013:000:2014
Nf-From: trsvax.UUCP!uhclem    May 16 12:04:00 1987


<restore "madadv.sav">$		I miss MDL...

>A. Is there a SCSI board, and

Yes, the Disk Cartridge System uses SCSI as the method of communication
to the host.

>B. Does it support all the features of SCSI (in particular, sharing a device
>   among several processors.)

No.  It does not support arbitration at all (the feature that allows
multiple hosts.  It is also a somewhat dumb adapter and does not even
get close to the upper transfer rates that SCSI allows.  Because of this,
the 1000/1010 HD controller can transfer data faster (1.6usec/byte typical)
as opposed to this SCSI adapter that rarely can clear 6usec/byte reliably.
(Not enough "F" parts, you see...) Since this is a DUMB adapter,
software must strobe the various control lines and perform all
handshaking and timing.  But then "software can do anything", as long
as you don't want it doing something else.

It can talk to multiple controllers, but that is not supported by Tandy,
since the Iomega uses a non-standard command set for SCSI operations
(as well as a set that changes with each new drive generation)
and the distributed driver is geared toward making the Iomegas run well.

<This information is provided by an individual and is not nor should be
 construed  as  being  provided  by  Radio  Shack or Tandy Corp.  Radio
 Shack/Tandy Corp has no obligation to support the information provided
 in  any way.   Just remember, Bob did not create the universe, despite
 what he says.  Many more people think Bill Gates did.  And the 6000 is
 still faster than the 3000.  But some  people don't check to make sure
 that  /usr/dict/words  is  the  same  size  on  both  machines  before
 performing their benchmarks based on that file.  (The 6000 version has
 2,357 more characters in it as distributed.  Might make grep run a bit
 longer.)  Good thing it wasn't a 386;  it might fuse.>
						
						"Thank you, Uh Clem."
						Frank Durda IV
						@ <trsvax!uhclem>
					...decvax!microsoft!trsvax!uhclem
					...convex!infoswx!trsvax!uhclem