David Nebenzahl wrote:

I'd like someone to try to name a data storage format (either physical
medium
or data format) that they think cannot be read today.

The point of digital media data loss isn't that the format can or can't
be read -- it's whether anyone, finding (for the sake of argument)
undeteriorated media that doesn't fit their current equipment will both
to spend the time, effort, and money to try to read it to see what's on
it. Sure, in a business setting, a spool of paper tape labeled
"Foundation charter" is something that's a likely candidate to be read,
transcribed onto modern media, and preserved. Grandma's attic, on the
other hand, isn't someplace you'd necessarily expect to find computer
data you'd pay (a lot) to have converted -- especially since most people
who don't work with computers and data storage probably aren't even
aware that conversion services exist.

If you find prints and negatives, you can see with your eyes what images
are stored. If you find a bunch of unlabeled CDs fifty years from now
(and you're 32 years old, and born the same year the last CD-R media
were made), are you likely to be curious enough about them to spend
significant money to find out what's on them? It's hard to imagine a
similar situation -- if I found letters in my Grandmother's estate
written in Sanskrit, I'd be able to at least recognize them as letters,
if not the language (I'm not certain I'd recognize written Sanskrit, at
least). It's more like finding a bunch of blank paper in envelopes --
would I take the time and trouble to figure out which of half a dozen
different invisible ink systems might have been used to write letters on
that paper, or just figure it was unused stationery that had never been
thrown away? And even if the latter, the medium isn't so completely
obsolete that I wouldn't be able to develop the ink myself if I had some
reason to suspect invisible writing; it doesn't depend on a technology
that hasn't been manufactured or supported in decades.

None of which has anything to do with Tom's arguments about digital not
being photography; he's saying that because there's a silicon sensor and
digital encoding involved instead of a medium that we view directly with
the image on it, it's something other than photography (I think -- I
haven't really found the argument completely coherent). I disagree, but
the issues of "digital is or isn't photography", "digital media can or
cannot be archival and remain readable over periods longer than a single
lifetime" and "photography is or is not art" don't seem even very
closely related, certainly not enough to cross over from one to the
other. I do agree with him in believing that digital media, even those
that aren't degraded, will become unreadable due to changes in
technology over time spans much shorter than a human lifetime.

Let's try this one: can your former employers, specializing in data
format conversion, read a Coleco Adam data tape? Hint: if you find one,
it'll look exactly like an obsolete audio cassette -- because it is.
But if you play it in an audio player, you'll get only a very loud, very
raucous blaring noise; most computer users today wouldn't even recognize
it as a data encoding signal (it doesn't sound at all like modem or fax
tones). Or how about the same storage media written by a Commodore Pet?
Both were fairly popular hobbyist computers in their day (around 25+
years ago), and both had at least a small business presence.

If you want a *really* obscure one, how about a Tandy Pocket Computer
data tape? I actually owned one of those, with the cassette interface;
it was already obsolete when I had it, in 1982...

--
I may be a scwewy wabbit, but I'm not going to Alcatwaz!
-- E. J. Fudd, 1954

Donald Qualls, aka The Silent Observer
Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

Opinions expressed are my own -- take them for what they're worth
and don't expect them to be perfect.