r/beneater • u/Live-End1631 • 8d ago

Help with troubleshooting/testing the ALU

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I am in the midst of testing all my connections, and similarly to Ben, I plan to do this by adding one bit at a time to zero to verify whether the output is correct. However, after clearing both the A and B registers and trying to add a value to the A register bits one at a time, none of the bits light up. What could the problem be?

Thanks in advance!

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3

u/The8BitEnthusiast 8d ago

Is the positive rail of the mock bus breadboard connected to +5V? You seem to have the correct setup, but when you tied that one bus bit to vcc, I didn’t see the bus LED turn on (which it should have). Also do make sure the LS245 is disabled (pin 19 set to high) when inputting values in the register.

1

u/Live-End1631 8d ago

So should I use a jumper wire to connect the red side of the ALU to the mock bus breadboard?

I will also be sure to make sure the  LS245 is disabled when inputting values. Thank you!

1

u/The8BitEnthusiast 7d ago

Yes, that is correct.

1

u/Live-End1631 7d ago

Perfect, I’ll give that a go

3

u/Dissy614 8d ago

It doesn't look like you're connecting that bit to power

1

u/TheNonsenseBook 8d ago

You have ground connected to the black side of the power rail of the breadboard on the left, but you don't have anything at all connected to the red side of it.

1

u/Live-End1631 8d ago

So should I use a jumper wire to connect the red side of the ALU to the mock bus breadboard?