The 7400 (variants 74LS00, 74HC00) is a 74-series logic IC with four independent 2-Input NAND gates.
.--\/--.
1A -> |01 14| -- +5V
1B -> |02 13| <- 4A
1Y <- |03 12| <- 4B
2A -> |04 11| -> 4Y
2B -> |05 10| <- 3A
2Y <- |06 09| <- 3B
Gnd -- |07 08| -> 3Y
`------'
Y is low if A and B are both high, and is high if either A or B is low.
Categories: 7400 series