When Sprint and MCI entered the alternate long distance market, accessing their services was a pain: You had to dial the local number, wait for their machine to answer, dial a 5-digit access code, then dial the area code and number you wanted.
In 1979, a local law firm was fed up with that and so they hired me to build them these dedicated autodialers. They attached to their Exeutone (tm) office phones, and they had just one button and one light. To make a call, you just push the button - the dedicated autodialer would dial the local access number, pause for 7 seconds for the machine to answer, dial the 5-digit code, and then stop. The lawyers only had to dial the area code and number as normal - the same number of button presses as a regular long-distance call. It should be emphasized that this was the ONLY autodialer available at the time which have a provision to pause for several seconds while dialing out.
I made about 15 of these, using hand-drawn, photo-etched, and drilled printed circuit boards. The circuit used a touch-tone generator chip coupled with a Programmable Read-only memory and a clock/counter circuit. An extra unit was entered into the IEEE Electronic Design Competition at UCLA, and it won first prize: A Hewlett Packard 41C calculator, the most advanced scientific calculator in the world. (Don't tell anyone I wasn't a UCLA student!)
More pictures below.
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| Me drilling the holes in the printed circuit boards. |
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| This was the announcement for the UCLA Electronics Design Competition. None of the judging professors realized that I wasn't a UCLA student. The first prize was an HP-41C calculator (worth $250 in 1980!) It was the first calculator with input/output ports on the back for peripherals, which I later leveraged for all subsequent inventions. |