home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.sys.amiga.hardware
- Path: sparky!uunet!timbuk.cray.com!walter.cray.com!paws
- From: paws@spam.cray.com (Daniel Baehr)
- Subject: Re: LUN 1 SCSI device
- Message-ID: <1992Aug12.092722.8257@walter.cray.com>
- Sender: paws@spam (Daniel Baehr)
- Organization: Cray Research, Inc.
- References: <10AUG199216433778@vx9000.weber.edu> <1992Aug11.072220.18797@walter.cray.com> <1992Aug11.203905.11589@ninja.zso.dec.com>
- Date: 12 Aug 92 09:27:22 CDT
- Lines: 71
-
-
- In article <1992Aug11.203905.11589@ninja.zso.dec.com>, Hans Ridder <ridder@zso.dec.com> writes:
- > In article <1992Aug11.072220.18797@walter.cray.com> paws@spam.cray.com (Daniel Baehr) writes:
- > >
- > >In article <10AUG199216433778@vx9000.weber.edu>, alewis@vx9000.weber.edu (ALEWIS) writes:
-
- > > In the world of SCSI there is no such thing as a LUN of ANYTHING other
- > > than 0. The SCSI ID, on the other hand, can be from 0-7. There are
- > > ways of putting more than 8 devices on a SCSI chain but that isn't
- > > supported on the Amiga. Grab yourself an ANSI SCSI spec and read all
- > > about it.
- >
- > I suggest you grab an ANSI SCSI spec. and read all about it. What would
- > be the point of having LUN's if they always have to be 0? Please check
- > your facts before posting such nonsense.
-
- In the most receint copy of the spec that I have they call the LUN
- what we call the SCSI ID and the SCSI ID is the address present on the
- databus when a device needs attending to. I thought the definition of
- LUN we were using was more inline with the way I*M uses it?
-
- >
- > Also, to clarify, there are *only* 8 SCSI ID's which means that there
- > can be *only* 8 SCSI devices connected to one bus. Except for semantic
- > arguments over whether a LUN is device, there is no way to get more than
- > 8, as you claim. The system's Host Adapter (commonly incorrectly
- > referred to as a "controller") counts as one device, so that limits
- > number of additional SCSI devices to 7.
-
- Correct. I should not have said there WAS a way to put more SCSI
- devices on a chain. Stupid of me. It was something that I read that I
- didn't understand correctly when I read it the first time.
-
- >
- [ stuff deleted ]
-
- > That's silly. Where in the world does it say "the controller should
- > allways [sic] be ID 0?" Go see what the SCSI spec. calls a controller.
-
- That point I took from a setup manual for one of my controllers. It "suggested" that you not use one of the SCSI IDs because
- the controller used it, as you pointed out above. I should not have
- said "proper".
-
- >
- > >| Daniel Baehr Work: paws@spam.cray.com Home: daniel_baehr@bearsden.UUCP|
- >
- > As to the original poster's question, I believe the A2091 has a jumper
- > to enable LUN support. I have no idea if it really works. I seem to
- > remember the A3000 has a bit in the "battmem" which is supposed to do a
- > similar thing. Since at least one of the SCSI related items in the
- > battmem is ignored, who knows if the LUN bit (if it exists) is checked
- > by the driver software.
-
- As was pointed out to me in e-mail some older SCSI drives used the I*M
- style of LUN addressing. I called IVS and I was told they support it.
- I not sure which definition of LUN he was using.
-
- >
- > -hans
- > --
- > Hans-Gabriel Ridder Digital DECwest Engineering
- > ridder@rust.zso.dec.com Bellevue, Washington, USA
- > {pacbell,pyramid,uunet}!rust.zso.dec.com!ridder
-
-
- Daniel Baehr
- --
- +------------------------------------------------------------------------+
- | Daniel Baehr Work: paws@spam.cray.com Home: daniel_baehr@bearsden.UUCP|
- | These OPINIONS are mine and mine alone. |
- +------------------------------------------------------------------------+
-