write-only memory
write-only memory: n. The obvious antonym to `read-only
memory'. Out of frustration with the long and seemingly useless
chain of approvals required of component specifications, during
which no actual checking seemed to occur, an engineer at Signetics
once created a specification for a write-only memory and included
it with a bunch of other specifications to be approved. This
inclusion came to the attention of Signetics management only
when regular customers started calling and asking for pricing
information. Signetics published a corrected edition of the data
book and requested the return of the `erroneous' ones. Later,
around 1974, Signetics bought a double-page spread in "Electronics"
magazine's April issue and used the spec as an April Fools' Day
joke. Instead of the more conventional characteristic curves, the
25120 "fully encoded, 9046 x N, Random Access, write-only-memory"
data sheet included diagrams of "bit capacity vs. Temp.",
"Iff vs. Vff", "Number of pins remaining vs. number of socket
insertions", and "AQL vs. selling price". The 25120 required a
6.3 VAC VFF supply, a +10V VCC, and VDD of 0V, +/- 2%.