Scott Chapman writes:
>Tape still has some characteristics that spinning disks can't
>quite match for particular use cases.
True, agreed.
Setting aside current pricing, what are the characteristics of hard disks
that make them better suited to particular use cases than (modern, current)
SSD?
Note that we have seen *several* entire classes of storage disappear from
the market, even in niche use cases and excluding persistent use cases --
meaning cases where the storage type was installed a long time ago and has
simply persisted through inertia but would never be selected if installed
now, even as a corner/niche case. In no particular order, here are some
examples:
- punch cards;
One of the last major use cases was voting, infamously Florida, 2000.
Though there are still some people that repurpose the remaining stocks for
note taking with pens and pencils.
- punch paper tape;
I may have recently seen a paper tape (or linked card deck?) player piano
available for sale, new, as a novelty. I hesitate because I'm not sure if
the card/paper tape aspect of the piano was merely simulated with the
actual playback based on electronic memory, perhaps embedded in the novelty
tape/card "cartridge." I didn't inspect it closely enough.
- mercury delay line memory;
- data cell drives (i.e. the IBM 2321);
A fascinating device but way before my time.
- the Exatron Stringy Floppy;
- floppy disks;
- magneto-optical disk;
I think Sony might still be manufacturing their MiniDiscs, barely,
primarily for the Japanese market, but these disks are clearly on their way
out.
- floptical disk;
- digital cassette tape (displaced by the floppy disk);
The original IBM PC was among the final wave of computers that could use
this data storage medium.
- sub-2.5 inch and >3.5 inch hard disks;
I think these are all gone now. Apple's recent discontinuation of its iPod
classic was the major, probably final blow to sub-2.5 inch drives. IBM
pioneered teeny tiny hard disks, as it happens. (If anybody knows where I
can find a 1.8 inch/320 GB external USB hard disk drive at a reasonable
price, please let me know via private e-mail.)
- VHS tape as digital storage;
You can still find VHS tape sold (but fading) for its traditional video use
cases -- e.g. convenience store closed circuit recording systems -- but VHS
tape as a computer data storage medium has disappeared, mostly because it
was never very good anyway. (Though it was "cheap" for a period of time.)
- Digital Audio Tape (DAT);
- disk packs (along with the Inmac catalog);
- bubble memory;
- phonographic cylinders;
- magnetic wire recorders;
- metal tape (e.g. UNISERVO);
- Kinescopes;
- many, many types of film media, including practically all of early film
sound recording types;
- smoke/vapor-based recording;
I use the word "recording" here quite consciously. These recording systems
could not be played back when they were invented and used. They were simply
used for studying the general behavior and characteristics of sound waves.
Now, thanks to digital processing -- high resolution digital scans of the
smoke imprints combined with computer-based reconstruction of the audio
that produced the imprints -- the information they contain can be
recovered. That's how the world's oldest sound recordings are now being
retrieved. Unfortunately Abraham Lincoln probably didn't speak into such a
mechanism, or at least his recording was lost, so it's extremely unlikely a
recording of his voice will ever be recoverable and playable.
- non-vinyl and 78 rpm phonographic records;
Vinyl records are still with us as a novelty.
- "donut" core memory;
This type of memory/storage persisted for quite a while in niche
military/space applications since it can be made extremely rugged and
durable.
Stone (and other durable materials) engravings have not disappeared.
They're still popularly used in building construction (cornerstones,
dedication plaques), monuments, trophies, wedding rings and other types of
jewelry, gravestones, sculpture and other works of art, spacecraft
(messages sent to aliens aboard deep space probes), warnings to future
people near permanent spent nuclear fuel dumps, and land surveying (e.g.
marking land boundaries), as examples. It's one of humanity's oldest
storage types, probably the oldest. (Cave drawings are old, too.) "Old" is
not at all disqualifying for a storage type. In fact there's been some
relatively recent innovation within this storage type, e.g. laser etching
precious gems.
Paper also shows no signs of disappearing as a storage medium any time
soon, including optical scan paper media ("fill in the ovals with a No. 2
pencil"). Optical scan paper media is very popular for voting systems.
DNA/RNA most certainly show no signs of disappearing, and they're extremely
old. It's a pretty safe bet that particular storage medium will be around
on our planet for another 1.5+ billion years. Let's hope so, anyway, though
it's a separate question what code(s) those media will be making live in
the future. Wooly mammoth and Neanderthal DNA sequences have been
recovered, so DNA is a pretty durable storage medium as long as the
environmental parameters are kept within certain bounds or as long as you
reproduce the storage periodically. :)
--------------------------------------------------------------------------------------------------------
Timothy Sipples
IT Architect Executive, zEnterprise Industry Solutions, AP/GCG/MEA
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E-Mail: [email protected]
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