Reminds me of a construction article in one of the amateur radio magazines in the mid 1960s. A small box with ferrite core memory for generating Morse code from alphanumeric keys. Not sure if it could also receive. It was a wondrous thing like something from science fiction. Up to then spring-loaded "speed bugs" were the fastest mechanical aids.
G3DML used to tell the story of his wartime training in morse code reception. He was failing to reach the required highest speed standard. So his boss sat him down for an intensive training session. He put a packet of 20 cigarettes on the table - and said they would only stop the session when John had smoked them all. He passed the test - although by the time of telling the story he had long graduated to cigars.