> On Mar 8, 2023, at 12:20 PM, Chuck Guzis via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 3/8/23 06:19, Paul Koning wrote:
>
>
>> I wouldn't exclude those, certainly not if they are relevant to the
>> evolution of the technology. Are X1 tapes (and Eliott tapes if they are the
>> same format, which I don't know) in some way anticipating LINCtape and
>> DECtape? Are they an independent invention of roughly the same concept?
>> For that matter, would you exclude DECtape on the grounds that it's single
>> vendor? I hope not. For that matter, I suspect the Uniservo I format is
>> specific to Univac, yet you can't very well exclude that from a history of
>> magnetic tape data recording.
>
> I view "captive formats" such as DECtape to be evolutionary dead ends.
>
> Consider, for example, the Datamatic 1000 tapes--I doubt that more than
> a handful of people here have ever heard of the system. A captive format.
>
> Or the early Uniservo metal tapes?
I would disagree with that blanket assertion, for two reasons. One is that
something isn't an "evolutionary dead end" only if nothing later was inspired
by it and constructed, to some extent, along similar lines. In that sense the
Uniservo tapes are not at all a dead end; instead, they are the ancestor of all
later tapes. Properties like metal vs. plastic media and 6 tracks vs. 7 or 9
or more are details.
Second, I would consider a format to be significant if it had a major market
presence and major place in the technology space. In that sense, DECtape I
clearly belongs -- being either the primary or a significant secondary storage
device for a decade or two of some of the world's most successful computer
lines.
Similarly, is DLT a "dead end"? It was captive to some extent until it spread
out, but then LTO replaced it. On the other hand, isn't LTO clearly an
evolutionary variant of DLT?
I'd agree that there are a number of other formats that were neither
significant players nor a significant influence on later work. The CDC
14-track tapes would fit that description, and the Eliot or X1 10-track tapes
most likely as well. But I would argue that "if it wasn't an industry or ISO
standard it doesn't count" is too restrictive a view, especially if you aim to
produce a history of the technology space.
paul
