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From: kev@hpcpbla.HP.COM (Kevin Jones)
Newsgroups: comp.periphs.scsi
Subject: Re: Which DAT: Archive or Wangtek ?
Message-ID: <9850026@hpcpbla.HP.COM>
Date: 5 Jun 91 07:14:09 GMT
References: <29162@neptune.inf.ethz.ch>
Organization: HP Computer Peripherals Bristol, UK
Lines: 73

WARNING: The following statements may be unintentionally biased
         since I am involved in HP's DDS DAT program:

> As far as I know, there exist two formats: DDS and Data/DAT.

Correct

>  The former does not allow random writing, while the latter does;
> this allows to mount a filesystem on a DAT tape.

Also correct.

> It's in this latter format that I'm interested in for
> near-line access.

"DDS versus DATA/DAT" WAS a format war which started over 2 years
ago. Companies scrambled into either the DDS camp or the DATA/DAT camp
according to their preferances. The main difference between formats
is that DATA/DAT supports a random write ability whereas DDS does not.
(DDS does support partitioning where a tape may be split into two
 logical volumes).

It was fairly obvious from the outset that 2 different formats were
not going to co-exist => One of them had to die.

The one that is about to die is DATA/DAT.
(Actually I thought it had died until Francesco mentioned it :-)

But I would say that since I work in HP's lab on DDS!!!!
So don't take my word for it. Look at the DAT marketplace and see
how many DDS compatible drives there are as opposed to DATA/DAT drives.

To the best of my knowledge the only company manufacturing DATA/DAT is
Gigatrend. I think that they have a machine out which can do both
formats (at what price ???). Other companies: Hitachi, Alps, ?JVC?
are "supporters" of DATA/DAT but I have not seen any products from
them yet.

Companies manufacturing DDS include: HP, ARCHIVE,
WANGDAT, SONY, WANGTEK.
There are other companies OEM'ing and selling DDS. I am not aware of
any DATA/DAT OEM sales.

In summary: Anyone buying a DATA/DAT drive should be aware that
            (IMHO) DATA/DAT technology is on the verge of extinction.

----------------------------------------------------------------------

There have been debates as to why DDS won over DATA/DAT. The main
factor seems to be complexity. DATA/DAT was an amazingly complex
tape format. This had 3 effects:
1. The end-product cost more than a DDS product. This didn't benefit
   DATA/DAT when a large percentage of "tape customers" did not want
   to use its random write ability.
2. DATA/DAT products development times were excessive. The result was
   DDS drives hit the market well ahead of DATA/DAT (apart from
   Gigatrend's product - but they were out there on their lonesome).
3. Develpment costs of DATA/DAT were prohibitive.


---------------------------------------------------------------------
Kevin Jones.                       | Hewlett Packard Ltd,
                                   | Computer Peripherals Bristol,
kev%hpcpbla@hplb.hpl.hp.com        | Filton Road,
                                   | Stoke Gifford,
Tel: 011 44 272 799910 (ext 22351) | Bristol.   BS12 6QZ.
                                   | ENGLAND.
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This response does not represent the official position of, or
statement by, the Hewlett-Packard Company.  The above data is
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without warranty of any kind.