Article View: comp.sys.amiga.tech
Article #14143SCSI direct
From: Patrick John Horgan
Date: Fri, 09 Mar 1990 05:09
Date: Fri, 09 Mar 1990 05:09
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I posted a few days ago to note that a friend had found a way to do SCSI direct on a 2090a. It seems that a bit that tells the dma chip whether it should read or write is never getting set, so the dern thing always thinks it's supposed to read. The work-around is to pull up bit 24 of the data buffer address (addr |= 0x1000000) in your SCSI direct packet when you write. Fortuitously, since the 2090a driver isn't setting this when it's supposed to it also leaves it alone:) The same code will work successfully with the 2091. The driver will overwrite the bit with it's own. The news I got today is that although the 2090 driver doesn't support SCSI direct, the 2090a driver, (when used with this method), works just fine with the 2090:) Patrick Horgan phorgan@cup.portal.com
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!wuarchive!texbell!texsun!newstop!sun!imagen!atari!portal!portal!cup.portal.com!phorgan From: phorgan@cup.portal.com (Patrick John Horgan) Newsgroups: comp.sys.amiga.tech Subject: SCSI direct Message-ID: <27712@cup.portal.com> Date: 9 Mar 90 05:09:05 GMT References: <DEVEN.90Mar6142851@netserv2.rpi.edu> <9310007@hpfcso.HP.COM> Organization: The Portal System (TM) Lines: 15