2 May
2002
2 May
'02
8:56 a.m.
On Thursday 02 May 2002 14:51, you wrote:
You would rather work the drive to death ?
When I break it, I fix it. I'm good at things like that.
At the
portion of the work where you just want to get the stuff
spooled to a file, you dont care about "block size" yet, you
just need to get it pulled off.
Unix will treat any device as a stream of bytes
And therein lies the problem. You know, any really old tape you are attempting to
recover
you really do not want to be running it thru the tape deck
very much
For tapes that far gone, a digital read won't work. You have
to build your own drive and sample the analog data coming off
the heads using A/D and not using the digital-based discriminator.
For tapes not that far gone (like the ones of mine that spent
days under water and then months with stachybactris growing on
them), I have a wet-read technique that prevents most shoe-
shining.
disks are huge these days, and the content is best
messaged
on a new disk rather than an old tape.
Agreed, *that's why the TAP format exists*, as well as Stan
Seiler's tapedisk/disktape system.
Do you see what im getting at here ? hello ?
No, I don't, because your entire example was disk-centric, Tell you
what... how about an empirical test?
Well since we already know the behavior, we already know
the results dont we ? Go buy a
9-track drive and hang it on your *nix box.
Let me send you a 9-track tape. You read it any way
you want. You send me the tape back.
Then you go get a second tape, and put the data
back on
any way you want. Then send it to me, and I'll tell you
if your technique works or not.
this is very predicatble if you know the raw behavior
of the devices isnt it
the whole idea was to point out some of this raw behavior 
2 May
2 May
9:57 a.m.
On Thursday 02 May 2002 15:56, you wrote:
Well i really meant the tape, its whats really suffering
the damage, sorry i wasnt more clear.
I havent gone that far ..
Fair enough, but remember my post was about cat vs dd, and
was not dealing with all these other issues being tossed
up, it was to point out that what he was doing would be easier
with a simpler tool
It certainly didnt apply to preserving the information
needed to rewrite a new 9 track tape.
I think your being a bit rough on me here, your givin me
a GI bath for things that was outside of the scope of my
focus.
Raymond
You would
rather work the drive to death ?
When I break it, I fix it. I'm good at things
like that. You know, any really old tape you are attempting
to recover
you really do not want to be running it thru the tape deck
very much
For tapes that far gone, a digital read won't work. You have
to build your own drive and sample the analog data coming off
the heads using A/D and not using the digital-based discriminator. For tapes not that far gone (like the ones of mine
that spent
days under water and then months with stachybactris growing on
them), I have a wet-read technique that prevents most shoe-
shining.
That i have done, it works for really old floppies too, some
may look at you funny to see a floppy head doing some boating
on a wet disk, but it certainly works
> disks are huge these days, and the content is
best messaged
> on a new disk rather than an old tape.
Agreed, *that's why the TAP format exists*, as
well as Stan
Seiler's tapedisk/disktape system.
I need to play with those tools, you hooked me.
Wrong i used
it as an example, the raw stream already fit
its intended destination in the hard drive case.
If the structure of what is on a tape depending only on the
bits written to tape you would be right. BUT IT DOESN'T!!!
Record marks on a tape are lengths of tape where NO BITS ARE
RECORDED. Your technique gets the bits, but misses the are-not-bits.
8315
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8315
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dquebbeman＠acm.org -
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