HDD deletion

  • Thread starter Thread starter alex
  • Start date Start date
will have to try this one...
tnx.
Click to expand...

Works well. I have been using this for a decade now.
Well, no first hand experience, but from what I hear they are quite
good...
Click to expand...
Of course, it is just a sales pitch, but anyway:
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Case Studies
If there is any DATA, anywhere ON your DISK or TAPE, it can be
RECOVERED. In short, our expertise is your reassurance: your data is
in the safest hands, anywhere.
Click to expand...

O.K. I have no issue with that. They don't claim to be able to
recover data that is not there. The problem with overwritten
data is that it is not there in a pretty strong sense.

Also a though experiment: If you have on layer of good data
and one layer of overwritten data below that and you can
read both (albeit the second one with dificulties), then
the HDD surface is able to hold at least twice the amount
of data than the advertised capacity. The same argument holds
with multiple overwrites.

My impression is that in recent years the limiting factor for
HDD capacity was not heads or electronics but the surface
covering which can take only so many bits in a specific
area before they start to bleed into each other.

Tape and floppies are different. The recording density
is not close to the material limit there. A 1.44MB floppy
can hold up to 20MB with speacial servos and possibly more.

Arno
 
Arno Wagner wrote:

My impression is that in recent years the limiting factor for
HDD capacity was not heads or electronics but the surface
covering which can take only so many bits in a specific
area before they start to bleed into each other.

Tape and floppies are different. The recording density
is not close to the material limit there. A 1.44MB floppy
can hold up to 20MB with speacial servos and possibly more.

Arno
Click to expand...


Hello, Arno:

20MB, on a standard 1.44MB diskette? Are there any commercially-available
floppy drives capable of performing such a feat?


Cordially,
John Turco <[email protected]>
 
Previously John Turco said:
Arno Wagner wrote:

<edited, for brevity>

Hello, Arno:
Click to expand...
20MB, on a standard 1.44MB diskette? Are there any commercially-available
floppy drives capable of performing such a feat?
Click to expand...

Actually it was done by adding laser-cut servo tracks (i.e.
_decreasing_ the maximum capacity!) that allowed the head to
track better.

The product was DOA because they charged too much for the
specially prepared floppies and because the floppies had
to be specially prepared in the first place.

Was 5 years back or more, if I remember correctly.

Arno
 
They are called LS-120 and LS-240 and manage 120MB and 240MB
respectively. And no, they can't do that on standard floppies.
Actually it was done by adding laser-cut servo tracks (i.e.
_decreasing_ the maximum capacity!) that allowed the head to
track better.

The product was DOA
Click to expand...

So dead infact that they even made a version that was twice
the original capacity. They must have sold very badly indeed.
because they charged too much for the specially prepared
floppies and because the floppies had to be specially
prepared in the first place.
Click to expand...

Gee, how else could they have been 'specially prepared'.
Was 5 years back or more, if I remember correctly.
Click to expand...

What a memory. Oops, err, INSIGHT.
 
Arno said:
Actually it was done by adding laser-cut servo tracks (i.e.
_decreasing_ the maximum capacity!) that allowed the head to
track better.

The product was DOA because they charged too much for the
specially prepared floppies and because the floppies had
to be specially prepared in the first place.

Was 5 years back or more, if I remember correctly.
Click to expand...

Actually the 20 died because of (a) poor marketing and (b) the rather
remarkable fragility of the drives. Imation came out with an improved
version that does 120 on the special diskette and there are drives in the
same family with 240 meg capacity--I've got one of those FWIW. The 240s
can also put 34 meg on a _standard_ diskette but you have to use their
proprietary software to both write and read it. With CD and DVD prices
being what they are it's kind of hard to justify the price of the 240 meg
diskettes though.

Panasonic is still making the 120 drives and they seem to be still available
<http://store.yahoo.com/alan-fm/lkm-f434-1.html>. The ATAPI 240s were
never available in the US except as a special order item, but there was a
USB model imported by QPS for which I can find one vendor who still claims
stock, (I started to paste the link but it turned out to be about ten lines
long)--go to <http://www.printnation.com/store/> and plug
"QPLS240USB" (sans quotes) into the search engine.

They do work as advertised, and the 240s and the second generation 120s will
also sometimes read a diskette that a standard drive won't and are
significantly faster on writes besides, but they're also IDE and only work
as boot drives on machines that have LS-120 support in the BIOS.
 
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