Datanetics part no. 01-02-638 is a full-travel Datanetics batch-fabricated array keyboard. This particular example has serial number 0156 and was manufactured in December 1970, making it a fairly early keyboard for Datanetics. The photos below are from the now deleted eBay listing 333868304514 “Vintage Datanetics keyboard - 1970 w/ early TTL iC's”, posted by seller anifurdr of store DVQs vintage electronics.
This keyboard makes use of TTL encoding, with the following thirteen ICs being used:
|MC7493P||2||4-bit binary counter|
|SN74151N||1||8-line to 1-line data selector/multiplexer|
|N7400A||3||Quad 2-input NAND gate|
|MC7410P||1||Triple 3-input NAND gate|
|MC7402P||1||Quad 2-input NOR gate|
|MC4008P||1||8-bit parity tree|
Considering the presence of two binary counters, a multiplexer and a decoder, it seems highly likely that this is a matrix scanning keyboard. There does not seem to be a clock, however, and the CKA and CKB clock lines into the two counters cannot be traced. Possibly this keyboard required an external clock signal.