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From: rbthomas@athos.rutgers.edu (Rick Thomas)
Newsgroups: comp.os.minix
Subject: Re: Tape backup
Message-ID: 
Date: 1 Oct 89 05:58:36 GMT
References: <48@me.chalmers.se>
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 81

> From: lasse@me.chalmers.se (Lars Persson)
> 
> Does anyone out in the jungle know anything about code for
> one of these tapestreamers that are connected to the FDC?
> This night was the third time that my 30M system crashed,
> and it is quite a lot of work to get it up again, so a driver to
> this streamer would save a lot of blood.

This is by way of an update to my similar request of 6 months or so
ago.  I still don't have what I consider an adequate solution.

I got the QIC-40 specs *free* from the standards committee.  Write to 
	Freeman Associates
	Management Consulting 
	311 East Carillo St.
	Santa Barbara, CA 93101
Ask for QIC-117 Rev A 19 Apr 88 "Common Command Set Interface Spec
for Flexible Disk Controller Based Mini Data Cartridge Tape Drives"
and QIC-40 Rev E 18 Sep 87 "Flexible Disk Controller Compatible
Recording Format for Information Interchange using 1/4-inch Mini Data
Cartridge Magnetic Tape Drives 40 Megabyte Capacity 20 Tracks,
10000Bpi, MFM Encoded" and QIC-107 Rev A 5 Jun 86 "Basic Drive
Interface for Flexible-Disk-Controller Compatible 1/4-inch Mini Data
Cartridge Tape Drives"

Whether the drive you buy is completely standards conforming is a
question for you to take up with your dealer and the manufacturer.  I
found that neither of them were *at all* helpful on this subject.  I
bought an Irwin drive without asking first.  I will never buy another
Irwin product again.

QIC-40 may not be very useful to Minix people though.  The interface
spec is strictly from the dark ages with lots of critical timing
dependent stuff that *must* be performed in software with timing
loops.  This is most likely because the floppy controller wasn't
designed for this sort of thing and doesn't know anything about the
devices so it can't do the time-critical stuff in hardware.  That may
be why the manufacturers are so reluctant to release the source code for
their MeSs-DOS based standalone backup programs.  They are not sure it
would work in any environment but their own carefully controlled
hothouse.

I have also gotten a non-disclosure agreement to sign from Tecmar.
They promise to send me anything I need to write a driver for their
tape drives.  But their drives are fairly expensive, and (worse) I'm
not convinced that I could put the source code in the PD if I did
manage to write a driver, because of the non-disclosure agreement.
Tecmar assures me "no problem" but they have not talked to their
lawyers about it, and I don't want to put in alot of effort
without some guarantees.

Has anybody looked into SCSI tape interfaces?  There are some very
cheap ($50 US) SCSI interface cards that are sold to talk to generic
SCSI disks.  Has anybody tried hooking up one of those controller cards
to a generic SCSI tape drive (eg those sold for Mac's -- or SUN's if
you are very rich!)?  Have you succeeded in getting interface specs
for them?

Rick
========================================================================
Rick Thomas, Manager
Supercomputer Remote Access Center
Rutgers University, College of Engineering
Brett and Bowser Roads
Piscataway, NJ 08855-0909

Phone: (201) 932-4301
Internet: rbthomas@jove.rutgers.edu
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There are lots of dangerous people on the streets of Manhattan...
	     muggers,  rapists,  mimes...
========================================================================
-- 

Rick Thomas
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