RTL was my first experience with digital circuit design. When I was a teenager in the 1960s, my neighbor was a sales engineer at Motorola. He saw me put up an

RTL was my first experience with digital circuit design. When I was a teenager in the 1960s, my neighbor was a sales engineer at Motorola. He saw me put up an antenna on the roof and guessed correctly that I was into ham radio. So he gave me a big Motorola databook of RTL components and said, "Let me know if you ever need anything, and we can send you some free samples." The book had had gates, flip-flops, everything. You could get an entire JK flip-flop in a little tin can the size of a TO-5 [1] (but with more leads)! I wanted to build an iambic Morse code keyer. This has two separate switches for your thumb and forefinger. Press with your thumb and you get one or more "dits". With your forefinger, you get a stream of "dahs". Squeeze them together and you get alternating dits and dahs, thus the "iambic" name. I designed the circuit, built it, and it worked great! Until I actually hooked it up to my transmitter (which was of course the point of the whole exercise). I didn't have much of a clue about RF shielding, and RTL wasn't very robust around RF energy. So the interference from my transmitter made the circuit go crazy! I never did figure out how to fix it, so I had to go back to a straight key. [1] https://en.wikipedia.org/wiki/TO-5 https://en.wikipedia.org/wiki/TO-5