Eventual fate of our machines

From: Eric Smith <eric_at_brouhaha.com>
Date: Thu Oct 8 03:01:30 1998

Ward Donald Griffiths III <gram_at_cnct.com> wrote:
> Yeah, Tim, but computers are made of more than single protons (so
> far). The half-life of molecules (and the frinstance computer cases
> made out of them) is a lot less -- not counting the magnetic charges
> in storage media.

And the magnetic media is likely to last a lot longer than the bits
in any EPROMs, EEPROMs, Flash memory, etc. This is especially pernicious
in devices that are "secured" against reading, like single chip
microcontrollers and EPLDs.

In the old days I made sure to back up the EPROMs in every device I
purchased. For new equipment now, it is not even worth the effort, since
even if I do back up the EPROM some other chip that I can't back up will fail.

IIRC, EPROM manufactureres have usually claimed a 20 year retention life.

I have some EPROMs that were programmed in 1977 and still read reliably.
Others that were written as recently as 1992 already have marginal bits.

If anyone has the idea that they will be able to save a computer made in
1988 for another 40 years, and then be able to demonstrate it working,
think again.

On the other hand, it will probably be possible to keep older hardware
like the PDP-8/e working for as long as TTL chips or suitable replacements
can be found.

Eric
Received on Thu Oct 08 1998 - 03:01:30 BST