vacuum-safe laptops ?

[Trei, Peter]

> -----Original Message-----
> From: owner-cypherpunks at minder.net
> [mailto:owner-cypherpunks at minder.net]On Behalf Of An Metet
> Sent: Friday, July 16, 2004 6:35 AM
> To: cypherpunks at minder.net
> Subject: vacuum-safe laptops ?
> 
> 
> 
> Does anyone *know* (first or second hand, I can speculate 
> myself) which laptops, if any, can safely go to zero air 
> pressure (dropping from 1 atm to 0 in, say, 1 minute.)

What's your application, exactly? A rocket? 

I don't know about rapid decompression, but one problem is
with the disk drives - the heads rely on entrained air to
maintain separation from the disk surface. Most drives are
not hermetically sealed, and have a (filtered) port to the
outside to equalize air pressure.

Some drives *are* sealed, and will operate at low pressure.

I've seen this issue disscussed in the context of computers
and laptops at high-altitude astronomical observatories:
most machines will suffer head crashes if you try to use
them at > 10,000 feet (jets maintain an internal pressure
altitude of about 5,000 feet). 



Some applications use solid state drives to get around
this:
http://www.globalspec.com/featuredproducts/detail?exhibitId=10540&fromSpotlight=1&fromSupplier=0

Some displays may also be a problem. This is more an 
issue for big plasma displays. Sony makes a special 
plasma TV for high altitude use:
http://www.superwarehouse.com/Sony_PlasmaPro_PFM-42V1A_S_Silver_42_Plasma_Display/PFM-42V1A_S/pf/330392

A useful article is at
http://www.iht.com/IHT/SUP/031999/digi-08.html

You might want to look at the Itronix GoBook Max.
http://www.gobookmax.com/

This device supposedly meets MILSPEC:
http://www.dtc.army.mil/pdf/810.pdf

which is a USG survivability spec. It includes an explosive decompression
test, but not to high vacuum.

...and of course, all this gets pricy.

Peter Trei