I recently embarked on a project to build my own mechanical computer using Legos. My inspiration came from thinking about different ways to use mechanical devices to compute things. I didn’t want to recreate famous early computers like Pascal’s calculator or Babbage’s difference engine because they were mechanically complex and lacked some fundamental components. Instead, I chose to work with a replica kit of Digi-Comp I, a simple 3 bit machine from the 1960s. My computer only had 2 bits and didn’t have a clocking mechanism, but it worked well. I received requests for more details after posting a video of my creation, so I wanted to explain the high-level concepts. The computer consisted of a memory structure to hold the state and a control circuit to change the state based on input. However, my control mechanism was not ideal and relied on manual operations. The most complicated part of the design was creating the memory using a flip-flop, a special digital circuit that can hold a state. Normally, a flip-flop is made using electronic gates, but I found a way to construct it without gates. I used a stick that could be pushed back and forth to represent the flip-flop state. To integrate the flip-flop into
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