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Newsgroups: comp.unix.bsd
Path: sserve!manuel.anu.edu.au!munnari.oz.au!metro!socs.uts.edu.au!syzygy!raz
From: raz@socs.uts.edu.au (The Inimitable Raz)
Subject: Re: [386bsd] Colorado Jumbo tape drive device driver.
Message-ID: <raz.721539888@syzygy>
Keywords: Colorado, No dice, Tape drive
Sender: news@socs.uts.edu.au
Organization: Computing Sciences, Uni of Technology, Sydney.
References: <raz.720786927@ultima> <1992Nov5.153537.1@vax.sonoma.edu> <1dchecINN4pk@hpsdlss3.sdd.hp.com> <1dgkbvINN5vc@hrd769.brooks.af.mil>
Date: 12 Nov 92 03:44:48 GMT
Lines: 43
root@hrd769.brooks.af.mil (Super User) writes:
> I was pursueing pretty much the same thread in comp.os.minix about a year
>ago. Does the Jumbo tape drive have a QIC number? If so, the address to
>write to for the complete scoop on the interface is available from
>Freeman Associates in California for FREE! If it does, drop me a line and
>I will scramble around here until I find all of my stuff.
YES! Colorado responded to my fax within 48 hours which, given the
experience of someone else here seems pretty good. Their advice was
- Get the QIC-40, 80, 117 specs. These are the minimal set
to get started. QIC-117 is apparently particularly tricky
to implement.
- Research floppy controller I/O. Apparently the drive
doesn't even look like a floppy to the floppy chip! What
this means in practice, I have no idea.
- Research the DMA and beware of its limitations.
- Read a text on error correction before ANY of the
above!
> I had the same thought for my QIC-40 floppy tape drive for minix. The
>actual interface was a relative snap (although I never did commit it to
>disk), but the error correction algorithm used is very scary. I had to
>sit at the feet of a mathematician for a solid week before I understood
>the rudiments of finite field mathematics. Reed-Solomon ECC is its name,
>and it is not for the faint of heart!!! The project was pretty much
OH NO! This is the same scheme used for CD ROM (unless I'm mistaken).
I once spent 4 hours getting a VAGUE understanding of it - nowhere near
enough to implement.
Can you tell me where to get copies of the standards I mentioned?
--
Bye for now.
- Raz
raz@socs.uts.edu.au (Roland Turner) (OH) 61 2 319 5700