In the good old days when men were men and computers were computers
(with front panel switches and all), you could accomplish it if you were
reasonably quick:
http://www.cs.man.ac.uk/CCS/s100/s100home.htm
"Thus the S-100 bus provides most of the voltages likely to be needed by
chips, in the form of unregulated DC rails of nominally +8V, +/-16V. By
unregulated, I mean full-wave rectified and smoothed by a single
electrolytic filter capacitor (a huge 180,000µF affair the size of a
baked-bean can, in the case of the main +8V power rail, which could
deliver getting on for 30 amps in some machines - enough for light
welding).
"A side-effect of the presence of this size of filter capacitor is that
enough charge is stored to let the system ride out mains dropouts
shorter than about half a second. I have often seen a Horizon or similar
machine sail blithely through a dropout that momentarily dims the room
lights, while modern PC/AT-clones in the same room reboot or hang."
Here's a picture of the inside of the IMSAI 8080 (the first computer I
used):
http://www.rdrop.com/~jimw/ims-2.jpg
Now THOSE are capacitors.
- Joe
Joseph S. Barrera III (joebar@microsoft.com)
http://research.microsoft.com/~joebar
Phone, Office: (415) 778-8227; Cellular: (415) 601-3719; Home: (415)
588-4801
The opinions expressed in this message are my own personal views and do
not reflect the official views of IMS Associates Inc.
