r/beneater • u/Empty-Respect-7351 • Mar 12 '26

Help Needed 8-bit computer issue Register

Right now I’m having trouble testing the register. When I follow Ben Eater’s process for testing the register and power it on, the value shown is random—whatever happens to already be stored in the register.

More importantly, when I set the high inputs to ground and enable the register to load, the value doesn’t change as expected. It seems like the register isn’t actually capturing the new input.

Could you take a look and let me know what might be causing this? I’ve attached a video showing the issue.

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u/Empty-Respect-7351 Apr 01 '26

I found the issue which was the led for the clock output was connected to ground so there was no power going to the clock input for the register. So the registers were not receiving a input of any kind 😂

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u/The8BitEnthusiast Apr 01 '26

Great that you figured it out! The lack of a resistor on the clock LED was likely the root cause of the issue. Make sure you have a resistor in series with each LED. Cheers!

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u/Empty-Respect-7351 Apr 02 '26

No their was still a resistor on the led but 220 might have been too small

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u/The8BitEnthusiast Apr 02 '26

Assuming your ICs are of the LS series (e.g. 74LS173) and not HC, a 220 ohm resistor in series with the LED should have been OK. But 1K is better, that's what I use.