[GreenKeys] Early use of TTY pictures

[jhhaynes at earthlink.net]

I'm just reading a Bell System historical document.  Says that in 1923
they were working on various sytems for transmitting pictures by wire.
One of the things they tried was scanning the picture with a photocell
and using that to punch a TTY tape where the characters space, dot,
T and M were used to represent four levels of blackness.  Then they
would send the tape and receive the picture on a TTY printer.

This didn't go very far - it was just a side note to other methods
of sending and recording a photo signal; but it's interesting that
they even thought of it.



jhhaynes at earthlink dot net