Electronic Arrays, Inc. was an American semiconductor manufacturer.
Keyboard encoder ICs
All of Electronic Arrays’ keyboard encoders handle 99 keys in quad mode with 10 output bits. N-key rollover is provided for each model. Presently, no datasheets for these encoders have been found.
|This model is advertised as being 99-key, although IC Master 1977 claims a 9×9 key matrix (which would be 81 keys)
|EA2007 is advertised as a pre-programmed EA2000 which “provides encoding for standard ASCII and EBCDIC keyboards”
EA2000 is the generic ROM table model, unprogrammed. It was listed a commercially-available keyboard encoder in US patent 4223893 “Electronic game”, indicating that it was manufactured at least as far back as 1976.
EA2007 is a pre-programmed EA2000. It was advertised as providing “encoding for standard ASCII and EBCDIC keyboards”. Since there is likely insufficient ROM capacity to encode both schemes in a single chip, one could presume that there were at least two EA2007 variants, one for ASCII and one for EBCDIC.
EA2030 produces binary sequential output for use with an external ROM. Key bounce suppression is provided, as is electronic shift lock.
An EA2030 encoder can be seen in the Volker-Craig VC404 terminal keyboard, with a manufacture date of week 49 1979.
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