Thought you guys my like this one... I talked about using a PCB board as
a PROM awhile back... Sure enough, it's been done, in a fashion. These
two pictures show what I'm going to call a MPROM, Mechanically
Programmable Read Only Memory.

http://petertodd.ca/persist/2006-02-04/mprom_front.jpg
http://petertodd.ca/persist/2006-02-04/mprom_back.jpg

A friend of mine found the circuit in the bin when they replaced the
security system at the building his studio is in. The rest of the board
is just lovely, all hand drawn curvy traces, with the occasional ridged
template drawn ground line... (I think my girlfriend was onto something
when she said I have two lovers...)

Actually the IC's on the board are a bit of a puzzle, none of the part
numbers are familiar, ADEMCO 525 anyone? Pretty sure it's digital logic,
there just aren't enough components other than the IC's for it to really
be anything else. The date codes suggest it's all from 1972-74

-- 
pete@petertodd.ca http://www.petertodd.ca
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