Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!ncar!boulder!bobk
From: bobk@boulder.Colorado.EDU (Robert Kinne)
Newsgroups: comp.sys.dec
Subject: Re: Exabyte (8mm) versus DAT (4mm)
Message-ID: <23327@boulder.Colorado.EDU>
Date: 10 Jul 90 22:43:28 GMT
References: <9007061713.AA01816@stc06.CTD.ORNL.GOV> <1881@proa.SV.DG.COM> <13113@cbmvax.commodore.com> <126@decvax.decvax.dec.com.UUCP>
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Reply-To: bobk@boulder.Colorado.EDU (Robert Kinne)
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In article <126@decvax.decvax.dec.com.UUCP> tarsa@abyss.zk3.dec.com (Greg Tarsa) writes:
>
>The *tape transport* is 8mm format, the electronics are Exabyte's own.
>I believe if you check (call Exabyte), you will find that 8mm tape
>drives are written in a digital format, not some analog adaptation.
>
>The issue of "DAT is digital, 8mm is analog" is a non-issue, probably
>concocted by DAT marketing to confuse things.
>
The magnetic particles on the tape don't know anything about digital
or analog.  It is a characteristic of the iron oxide that it is
easily saturated, and once the magnetizing signal goes beyond the
linear range, the tape quickly reaches saturation.  The magnetic
heads used in helical scan recording are very similar to video-
heads, and a very similar technique for data storage was pioneered
by IBM (of course!) during the 1970s, resulting in an archival
storage technology with helical scan cartridges.

Disclaimer: I have no connection with Exabyte or with IBM, and I
don't know any more about digital audio than the things I read in
the trade press.