[GreenKeys] (no subject)

[Harold Hallikainen]

Interesting device! It looks like a tape printer and a punched tape reader
(TD). The tape printer is interesting in that it appears to use a capstan
to move the tape forward. I see what appears to be "bubbles" embossed in
the tape on the feed side. I wonder if the blank tape was embossed like
this so it would "grab" the bumps on the capstan.

I also see a switch on the right that is hit by a pullbar. That's clever!
Another on the left seems to hit the bell.

The tape reader is interesting. Instead of a distributor like the model 14
TD, it appears there is a cam that pushes up the hole sense pins one at a
time. I suspect there is a switch for each of the hole sense pins. If they
are open when the pin is down and close if the pin can go up (mark), and
the switches are in parallel, we get the parallel to serial conversion by
just sensing the holes one at a time. Again, clever!

Harold
https://w6iwi.org