Re: TASS - Mark IV Bug

[hjohnson@pluto.njcc.com (Herbert R Johnson)]

On Tue, 19 Aug 1997 07:41:05 -0500 (CDT), droege@wwa.com wrote:
*>
*>The question for you, learned colleagues, is "does shining a 
*>light on an EPROM increase or decrease the access time?"
*>
*>Tom Droege

I would guess that the photons inject electrons into the transistor
junctions that drive or are driven by the address and data lines. Maybe
precharging the junctions reduces the dV/dt, i.e. the switching
speed, by reducing the junction potential "width" and thus the capacitiance
C is proportional to dV/dt. Something of this order.

In any case, try faster EPROMS, and covers. Maybe a higher spec version
too, in case they get hot (MIL spec for instance). Good luck!

Herb


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Herbert R. Johnson                      voice/FAX 609-771-1503 day/nite
hjohnson@pluto.njcc.com                 Ewing, NJ (near Princeton) USA

                 occasional amateur electronic astronomer
               supporter of classic computers as "Dr. S-100"
   and senior engineer at Astro Imaging Systems: old photons to new bits!