01How Computers Work (online)

Interactive circuit laboratory 05

Eight-bit ALU

Choose two eight-bit inputs and an operation; inspect the result and status flags.

Prediction before clicking

Only the lowest eight result bits fit. Signed overflow and unsigned carry-out convey different facts.

Loading interactive controls…

What the simulator is showing you

Only the lowest eight result bits fit. Signed overflow and unsigned carry-out convey different facts.

Try to predict the next output before changing the input. A prediction is evidence that you understand the mechanism. If the result surprises you, trace the bit values or the stored state explicitly.

Carry-aware addition, diagram of connected labeled components
Carry-aware addition. Follow the arrows to identify where information travels and what each block contributes.

Go deeper into the explanation

These experiments are simplified teaching models. The rules are intentional and inspectable, but they do not simulate transistor propagation delay, power consumption, or real processor pipeline details.