[GreenKeys] Dual head model 14 TD photos

[Jim Haynes]

On Wed, 7 Nov 2012, Duncan Brown wrote:

> Teletype Corp. Bul 141B (1945) has some description of this machine.
> Doesn't say who used it, but does describes the de-multiplexing
> process:   put two page printers in series, set the range finder of one
> to the high end of the scale for channel A; set the other to the low end
> for channel B!
>
The 1942 version of 141B does not mention the two-headed version; the
1964 edition does show it.  No mention of the crypto version, but I
guess anyone who has a need to know knows about it.