Terry built a LED bar display clock using only logic ICs:
Although I’m way too late for the 7400 contest, I had built a chips-only digital clock from 4000-series IC’s The time was displayed by columns of LEDs i.e. first columnt was 1-12, and the led for that hour would be lit. The next column was the tens-of-minutes (0-5), and the last of course the minutes (0-9). I used a whack of 4029’s, 4514, 4017’s and whatever else I had around, and tapped a transformer for the the 60hz. In one of my earliest attempts at PCB making I made the 3-column LED display. It was at that time the most complicated logic circuit I had ever built, and I was rather happy that it worked! I ran it in my workshop for about a week and it kept time really really well. So in the spirit of ‘what can you build with only logic chips’, humbly give you my strange creation
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