Re: "What if" question



bill.sloman@xxxxxxxx wrote:
On Jan 4, 2:07 am, a7yvm109gf...@xxxxxxxxxxx wrote:
On Jan 3, 7:59 pm, bill.slo...@xxxxxxxx wrote:





On Jan 3, 6:49 pm, a7yvm109gf...@xxxxxxxxxxx wrote:
If time travel to the past were possible and I brought a PATA hard
drive with me, would the scientists and engineers of 1966 get it to
work? Assuming I told them nothing would they figure out the
principles behind it? If so, how long would it take? How would they do
it?
Modern hard disks depend on "giant magneto-resistance" in the reading
head to be able to read the magnetic field of the disk surface.
It wasn't discovered until 1988
http://en.wikipedia.org/wiki/Giant_magnetoresistive_effect
You'd probably need ion-beam milling to identify the different
metallic layers in the reading head that give you the giant magneto-
resistance, and that only hit my radar in the late 1980's.
At the time it would probably have been an example of the sufficiently
advanced technology that was indistinguishable from magic.
Doesn't anybody around here know their technology?
--
Bill Sloman, Nijmegen
Right, but they could have figured it out eventually. I think.

They might have been able to figure out that the data density on the
disk was some four or five orders of magnitude higher than anyone
could manage in 1966 - in 1980 my wife dropped a hard disk cartridge
that slotted into a a hard disk drive the size of a washing machine,
and managed to lose all of the data she'd stored in the 10 Mbyte of
storage it offered.

I guess they might have figured it out how to get the extra density by
1988 ...

I mean it's electrical, not magical.

It would have looked pretty magical back then.

GMR may be only two decades old, but the old, non-giant MR effect
isn't.
I sometimes wonder what would happen if modern dance music were played
in a 60s disco.
Especially stuff like euphoric trance with a melodic line that just
blows you away. Too much bass probably, destroy the speakers of the
time.

Compact disks weren't around in 1966

http://www.oneoffcd.com/info/historycd.cfm

and while you could digitise audio and record it on video tape
recorders back then, the particular encoding now used wasn't
standardised until 1985 (J. Audio. Eng. Soc. volume 33 pages 975-984)
so the lucky recipient would have had some trouble recognising audio
tracks in the data in the disk.


They had pretty fast tape drives. The real tapes, huge. Of course, to install one of these you had to clear out part of the living room and have the electrican run an extra mains line.

--
Regards, Joerg

http://www.analogconsultants.com/
.



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