Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!van-bc! From: lphillips@lpami.wimsey.bc.ca (Larry Phillips) Newsgroups: comp.sys.amiga.tech Subject: Re: Multiple Amigas on a SCSI Bus. Message-ID: <1356@lpami.wimsey.bc.ca> Date: 6 Apr 90 14:55:58 GMT Lines: 41 Return-Path: To: van-bc!rnews In <10667@cbmvax.commodore.com>, mks@cbmvax.commodore.com (Michael Sinz - CATS) writes: >In article writes: >> >>Ok, I'm about to get a 500/590 for hacking on (Cheapest >>alternative 'till the 3000 comes out, then a good X >>terminal). My housemate has a 1000/590 and we'd like to >>share SCSI devices. Is this possible?? Is it feasible?? > >Is it possible? Well... You need a new device driver, modify one of the >590s to be at a different SCSI ID, and write some from of arbitration. >(The best bet would be to have one of the devices act like a drive to >the other and then have that one control the disk. This makes it like a >server/client. Sharing the drive otherwise comes into the problem of who >has the right to read/write/cache any part of it.) I am currently awaiting delivery of a 2091, so this and a couple of other comments about the 2091 are of interest to me. I agree that the best bet would be, as you say, to write some form of arbitration making one host adapter look like a disk, but I am wondering if the 2091 supports SCSI bus arbitration (lower level than the arbitration you are speaking of), so that, for example, an IO device could act as a master on the bus. Disconnect/reconnect... I noticed a posting from Dave Haynie that mentioned the 2091 disconnecting between the command and data phases in case something else needs to use the bus. Is this 'generic' disconnect/reconnect capability? It would be real nice if it is, so I could keep the tape streaming without having to go to a separate tape controller. If it has this capability, can it be turned on/off on a physical device basis for those devices that do not support the capability? -larry -- Entomology bugs me. +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+