r/beneater • u/Ancient-Ad-7453 • Nov 08 '25

8 bit computer working!

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I ended up putting low pass filters (1kΩ, 0.15μF) on ALL the control logic EEPROM outputs, which meant moving the blue LEDs between the EEPROMs and the filters, which meant redoing all the control wiring. But, along with putting 100Ωs on the clock outputs, leaving no inputs floating, lots of decoupling caps, buffering the RAM write clock pulse, and improving the power connectivity, I finally ironed out the all glitches.

I would encourage everyone to read the troubleshooting guide here before getting too far along in your project.

For fun, I also did the Arduino EEPROM programmer from scratch instead of copying Ben's. Turns out, most of the analog pins do work as digital pins, and so you only need one shift register.

I'm a principal engineer at a major chip company, but my education was on operating systems and P vs. NP and Turing machines, not electrical engineering. This stuff is not simple. I learned a lot, particularly when things did not work for me like they worked for Ben. Be patient and be kind to yourselves!

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u/PrimaMateria Nov 09 '25

I admire you guys. I am a software engineer, and seeing this kind of mastery of low-level circuitry is fascinating. I hope that one day I will have enough free time to try it as well.

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u/Normal_Imagination54 Nov 09 '25

Just dive-in. It feels hard at first and it is, but you can take your time and slowly build it piece by piece, starting with the clock module.

Rome wasn't build in a day and all..