Xref: utzoo comp.sys.mac.comm:2041 comp.sys.mac.hardware:7595
Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!smsc.sony.com!dce
From: dce@smsc.sony.com (David Elliott)
Newsgroups: comp.sys.mac.comm,comp.sys.mac.hardware
Subject: Re: Can I Back Up my Hard Drive on my VCR
Message-ID: <1990Dec31.161905.8869@smsc.sony.com>
Date: 31 Dec 90 16:19:05 GMT
References: <18220@thorin.cs.unc.edu> <1990Dec27.155820.4783@batcomputer.tn.cornell.edu>
Organization: Sony Microsystems Corp, San Jose, CA
Lines: 35

In article <1990Dec27.155820.4783@batcomputer.tn.cornell.edu> mha@batcomputer.tn.cornell.edu (Mark H. Anbinder) writes:
>There's no reason that you couldn't use a VCR, in theory, to store large
>quantities of digital data.  The problem is, video tape is NOT really a
>digital storage medium (I think...) so anyone creating a method of using
>video tape for backup would have to do some creative digital to analog
>conversion (and the reverse to read the tape back).

No magnetic medium is "really a digital storage medium".  Digital
data must always be encoded into an analog waveform to be placed onto
a tape.  With digital encoding, the waveform is recorded at saturation
levels to assure the clearest signal.  It's probably useful to note
that the first commercial digital audio tape setups were done using
videotape and a device called a PCM encoder/decoder.  It's also
useful to note that there exist devices that use magnetic and even
optical media with analog encoding (still video cameras such as the
Sony Mavica and Canon XapShot, and the laser videodisk).

The real problem with using a typical home VCR is that it just isn't
made for reading fast streams of data.  If you have to stop and back up, it's
almost as bad as using an audio cassette recorder.  For streaming, the
VCR can do a great job, but again that only helps if the computer
can keep up.  The controller can probably buffer up some data, but
eventually you have to stop.

In my opinion, the "my VCR should be useful as a backup tape drive" is
something along the lines of "my TV should be useful as a monitor",
"my monitor should be useful as a TV", or "my CD player should be
adaptable to be a CD-ROM reader".  Sure, it's possible, but the
cost of adapting a unit not designed for a task can often be as
high as buying an additional unit.

My advice to the original poster is to invest the money in a 45MB
removable drive, some cartridges, and a copy of Retrospect.  Backups
with this setup are a snap (especially with Retrospect 1.2), and you
get the additional benefits of an extra hard disk unit.