“You can make everything from a combination of NAND gates”. There usually follows a demonstration of simple AND, OR, and XOR gates made from NAND gates, and maybe a flip-flop or two. Then you ...

The Dr. has since built AND, NAND, OR, NOR, XOR ... NAND gate. With the two diodes reversed and a 910 Ohm resistor removed, a NOR gate is created. The next step was to build a S-R latch using ...