Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!apple!ames!eos!shelby!portia!roadman
From: roadman@portia.Stanford.EDU (arthur walker)
Newsgroups: comp.sys.amiga
Subject: Re: Should I buy a cheap SCSI tape drive?
Summary: 3M tape drives
Message-ID: <8418@portia.Stanford.EDU>
Date: 20 Jan 90 18:03:00 GMT
References: <5841@netcom.UUCP>
Sender: arthur walker <roadman@Portia.stanford.edu>
Organization: Stanford University
Lines: 41

In article <5841@netcom.UUCP>, hue@netcom.UUCP (Jonathan Hue) writes:
> 
> I picked up a free computer magazine here called "Microtimes" and a place
> called HSC Electronic Suppy has 3M MCD 403 SCSI tape drives for $129.
> They are new and in their original boxes.  They take DC2000 cartridges
> and hold 40MB.  If these are the drives I'm thinking of, they are ridiculously
> slow, something like 22K/sec, but at $129 they look pretty good.  I think
> Apple sells these drives as  Mac peripherals.
> 
> Anyway, is it worth buying one of these to use with my A590?  Will Commodore
> support a generic SCSI tape drive soon?  Is it possible for me to write
> a program that talks to scsi.device to write to the tape drive?

I don't know if the current or future drivers for the 590 will support
SCSIdirect.h.  If so, and if SCSIdirect.h doesn't presuppose a SCSI block
size of 512 bytes, then you will be able to do it.

The drives are indeed slow, but have the advantage of being block-addressable
rather than streaming, which means that if you can find a disk driver source
you are going to have an easy time of it and the resulting drive will fit into
the amiga scheme quite nicely.

I am led to believe by the makers of a mac backup utility called Retrospect
that the 3M tape supports disconnect/reselect; the mac SCSI manager does
not, however, which means you pretty much can't multi-find while doing 
backups or more infuriatingly, tape formatting.  The Dantz people got tired
of waiting for 7.0 and wrote a disconnecting SCSI managerjust to use with
Retrospect.

If you write such a driver, please let me know.  I am using the tape drive 
on a SCSI bus shared by am amiga and a mac II, with (sigh - it was highly
configurable for its time!) a C LTD controller, whose last set of drivers
gave some public access to the SCSI bus, but only for 512 bye blocks. For 
now, the mac thinks the amiga partitions are A/UX partitions and lets me
do image backups; I'd like to be able to do more than inquire from the 
amiga, and I expect that someday I'll have an amiga SCSI host that supports
SCSIdirect.

art walker
roadman@portia.stanford.edu
walker@meggie.stanford.edu