Lesson 15 of 48
Boolean algebra
Truth tables and gates — the arithmetic underneath the hardware.
Two values, a handful of operations, complete rules. One gate — NAND — suffices to build everything above it, which means every chip you have used is an enormous pile of one operation.
Do this
Build XOR out of NAND gates only, and verify it with a complete truth table you filled in by hand — all four rows, every intermediate wire.
The question that unlocks the next lesson
Boolean OR is true when…
- Aexactly one input is true
- Bat least one input is true, including both
- Cboth inputs are true
- Dneither input is true