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From: lphillips@lpami.wimsey.bc.ca (Larry Phillips)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Archive tape drives for sale
Message-ID: <2009@lpami.wimsey.bc.ca>
Date: 20 Sep 90 23:27:48 GMT
Lines: 32
Return-Path: <lpami!lphillips>
To: van-bc!rnews

In <92650@srcsip.UUCP>, carpent@SRC.Honeywell.COM (Todd Carpenter) writes:
>
>AIGH!!   You people talking about SCSI tape drives are JUST doing it to torture
>those of us who are stuck with the A2090a controllers!  You are SO cruel!

I have successfully run a SCSI streaming tape drive on the 2090A.

>So, that brings on a serious question:  Has anyone managed to get the A2090a
>patched up so it can be used with a SCSI tape?  I would be willing to pay for
>it, even!  (I know, I could *pay* for a new controller, too.  But I only have 1
>SCSI drive, and 4 ST506.  Another SCSI controller doesn't do me a whole lot of
>good, especially since I could hook up another 5 to this one, plus the tape
>drive.)

You don't really need to patch it. The only bad bug is that the DMA chip does
not get set up to transfer from memory to the device during a SCSIDirect writew
operation. You can kludge your way around this by turning on bit 24 of the
address of the memory you want to write out (ie. the data address). Bit 24 is
the low order bit of the high byte in the longword of the address. As an
example, suppose you wanted to write the contents of location $C00124 to the
device... the address you would supply is $01C00124.

-larry

--
It is not possible to both understand and appreciate Intel CPUs.
    -D.Wolfskill
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|   //   Larry Phillips                                                 |
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