The Morse demo required a bit of research and experimentation. It's note a trick to get the 1401 to emit Radio Frequency Interference. One popular unofficial use of these machines was the generation of music on a nearby radio. The seventh harmonic of the machine cycle time (11.5 microseconds) was in the AM broadcast band, and it was easy to hold one of those new-fangled transistor radios near the machine, where variations in operations could modulate that "carrier" The trick is apparently how to get it to shut up, or at least be quiet enough to allow a listener to distinguish intentional tones from baseline noise. In an attempt to create plausible morse code, the following program allows experimentation with variants on the tone generation scheme.
The source code (1401 autocoder) is mmtest.ac, and resulting card deck image (with appended message to send) is in mmtest.txt.
To run this program, place the deck in the 1402 card reader,
and press START RESET, then CHECK RESET
(on both console and reader) the LOAD on the 1402.
or command simh with
at cdr mmtest.txt
although you should be aware that simh does not actually
radiate substantial energy in the AM broadcast band.
Sense switches select one of four functions for the Mark portion of a tone (switches B and C), one of the same four functions for Space or silence (switches D and E) and whether the Space functions should operate from memory in the CPU (Switch F on) or from the 1406 extended core unit.