[GreenKeys] [External] Model 33 in the wild

[Jones, Douglas W]

From: Hugh Pyle -- Thursday, April 23, 2026 1:12 PM
> I'm planning to drag a Teletype out of the basement and bring it to the Clark Art Museum in Williamstown, where they are hosting "Analog Day" show-and-tell. 

But but but ... sputter.  Teletypes are just as much digital devices as any modern computer.  The difference is that Teletypes (especially old ones) are mechanical, not electronic.  All those levers, push rods and whatnot are doing digital logic.

If someone wanted, it would be entirely possible to build a fully mechanical digital computer using the fundamental mechanisms of a Teletype.  The selector latches serial data into the 8 bits of a mechanical register.  The blocking levers transfer the data from this register to a data bus (the codebars).  The stunt box decodes the value in the code bars to enable stunts like CR and LF, while the typing mechanism decodes which character to type.

While the Teletype mechanism can do just about any logic you want, and it has a register in it, what it doesn't have is RAM.  Teletypes are even pipelined -- the selector mechanism is busily receiving the next character while the previous one is being printed.  From that perspective, the selector latches are the interstage register linking the receive pipeline stage to the print pipeline stage.  How cool is that!

            Doug Jones