[GreenKeys] WU 22-A tape transmitter

[Jim Haynes]

This is a reader only, has no transmitting distributor, so it won't be
usable for TTY unless you attach it to something like a UART.  W.U.
had several designs of these things used in different contexts.

The original use was in time-division multiplex systems using big
faceplate distributors for transmitting and receiving.  Later they
were used in various switching system applications where it was
convenient to have the tape reader output in parallel-wire form.

I don't know that there is any documentation, but they are simple
enough you can trace out the wiring yourself.  The octal plug shown
with this one suggests it was used in some amateur capacity.