Newsgroups: comp.unix.sysv386
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!ispd-newsserver!ism.isc.com!ico!rcd
From: rcd@ico.isc.com (Dick Dunn)
Subject: Re: tape drive info wanted.
Message-ID: <1991Apr25.174716.3500@ico.isc.com>
Summary: more exabyte info
Organization: Interactive Systems Corporation, Boulder, CO
References: <1991Apr8.124255.26553@qut.edu.au> <1991Apr25.015612.1847@pegasus.com>
Date: Thu, 25 Apr 1991 17:47:16 GMT

richard@pegasus.com (Richard Foulk) writes:

(regarding 8mm tapes)
> Don't buy certified data tapes -- they're a lot more money for the same
> item.  Regular Sony video tapes perform just as well...

They're not (quite) the same item.  The data-grade tapes come out of the
same manufacturing process as the video tapes, so in that sense they're the
same--but the data-grade tapes are selected.  A tape that fails the data-
grade test becomes a video tape.  Still, the video tape is acceptable.
You'll get more errors--normally all recoverable, but since a bad spot
causes a skip on the tape, you get somewhat reduced capacity and slower
overall data rate.

However, it's about a 2:1 difference in price of tapes, while the
difference in performance/capacity is much less, so the video tapes are
still a reasonable deal.  I think I'd use data-grade tapes for serious
archival.

> (Error correction capabilities on the Exabyte drives are very
> impressive and seldom used -- at least with Sony tapes.)

Yes and no...they *are* impressive, but they do get used fairly often.  You
don't normally see the error correction done with ECC, but you will see the
bad-spot skipping.  The error correction has to be good because it does get
used.

> >>- Exabyte is the sole manufacturer of 8mm tape drives. They have
> >>  higher bandwidth and capacity than 4mm tapes. They may do a better
> >>  job of read/write error handling.
> >
> >I find this hard to believe, especially when you pick up a copy of a 
> >unix rag and find advertisements from companies like media cybernetics
> >who have thier own 8mm product.
> 
> All the 8mm vendors buy from Exabyte, a subsidiary (or something like that)
> of Sony.

Ack!  No!

Yes, all the 8mm drives are ultimately based on Exabyte's products...but
Exabyte is NOT a subsidiary of Sony (and they would probably not like it
much if you said that!).  They buy the drive mechanism from Sony and add
their own electronics and firmware.
-- 
Dick Dunn     rcd@ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
   ...While you were reading this, Motif grew by another kilobyte.