Re: Audio-capable, computer-interfaced DAT drives? [Summary]

From: Dominic Dunlop (dominic@onions.natcorp.ox.ac.uk)
Date: Fri Nov 06 1992 - 07:53:02 CST


On 21st October, I wrote:

> We might be in the market for a DAT drive with an interface to a
> SPARCstation, but we'd want it mainly to handle audio material rather
> than boring old back-ups. It wouldn't matter whether it played back
> through an audio jack, an optical fibre, a co-ax, or SCSI (although
> some combination including the latter would be nice), just so long as
> one could send it commands to skip to index marks over some sort of
> interface -- maybe even RS232. It has to be able at least to play
> back 44.1 kHz audio sampling, although I'd hope for full record and
> play at 48, 44.1 and 32 kHz. And SCMS is right out: our need for
> multi-generation dubbing is legitimate.
>
> So, some questions.
>
> 1. Can DAT back-up devices handle audio material at all?
>
> 2. If so, can they record and play back digitized audio over the
> SCSI bus? (Or have their ROM-based brains, like those of almost
> all CD-ROM players, been lobotomized to disallow this?) (Grrr!)
>
> 3. Given that audio tapes can be handled, how accurately can they
> be controlled? (Skip to index, write index, A-B repeat, that sort
> of thing.)
>
> 4. If DAT back-up devices don't handle audio, what semi-professional
> (we don't want to afford professional) equipment is there out
> there with some sort of computer control interface?
>
> 5. Characterize the interface. Does it conform to any particular
> standard (given that standards for such things exist at all)?
>
> 6. What sort of control does it offer?
>
> 7. What's the bottom line -- how much, in a currency of your choice,
> will this stuff cost me?

It's high time I summarised the response to the net.

To answer the questions:

1. In general, DAT back-up devices cannot handle audio. Technically,
    the reason is that computer data on a DAT has extra levels of
    error-correction relative to audio data, and most drives refuse
    to read tapes without data-type error correction, and will only
    write tapes with enough error-correction for data. Legally, the
    reason is that the suppliers of DAT back-up devices do not want to
    tangle with record companies' lawyers.

    The biggest exception to this gloomy picture is Silicon Graphics Inc:
    their Iris Indigo workstation supports a DAT drive which will read
    and write audio DATs. As far as I have been able to establish, this
    drive is internal, and isn't yet supported for audio transfers
    by other SGI workstations, never mind by non-SGI systems. (SGI
    also supplies a CD-ROM drive which will read audio data.)

2. Yes, for the SGI Iris Indigo; not applicable elsewhere. The SGI
    drive also has an audio out jack.

3. The SGI Iris Indigo supplies a control program which does these
    things: it's said not to be stunningly friendly. But, as the
    capability's there in the driver, one can write one's own.

4. The machine of choice here seems to be the Panasonic SV3900. It
    has an RS232 (or similar) control interface. Software is
    available (but only for PCs and Macs) to control 6 or 8 machines.
    Alternatively, specialist companies (see below) can hack
    domestic equipment for computer control.

5. There a standard (AES/EBU? Who knows?), and Panasonic follows it.

6. Panasonic? ``Good.''

7. An Iris Indigo with a DAT drive runs out at over $10,000 list in
    the US. (More if you want a useful amount of memory and more than
    no disk.) The Panasonic SV3900 costs something over pounds 1,000,
    with control software extra.

Thanks to the following for their responses:

Loren Buchanan, Naval Research Lab, Washington, DC
Tim Channon, A&D (or thereabouts -- see below)
Guy Harris, Auspex
Peter Ilieve, Memex Information Systems
adk, Edinburgh University
Pasi Korhonen, Ripoff Industries [sic]
David Sheppard, MIT Media Laboratory
Warwick Smith, Warwick Smith
Archer Sully, Frostbite Falls Pinochle and Bird Watching Society [aka SGI]

If you decide that you have to have an Iris Indigo, call SGI on +1 415
965 1026. (That's an old number. Hope it still works.) Me, I'm
locked into Sun for the moment.

If you need a custom solution to a problem of this type, call Tim
Channon on +44 635 40297 or send email to tchannon@black.demon.co.uk.
He's been involved in a project to make a (now discontinued model of)
DAT recorder capture selected audio material from digital satellite
feeds. Tim is associated with a company called A&D on +44 734 844545
(ask for Ian Harley) which, among other things, sells and supports the
Panasonic machine.

-- 
Dominic Dunlop



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