74LS Series - Texas Instruments SN74LS00N, This is the Texas Instruments SN74LS00 quadruple 2-input NAND gate IC from the 74LS family.
This is part of a range of low power Schottky devices offering the same speed as standard TTL but at a fifth of the power consumption.
Texas Instruments SN74LS00N Quad 2-input Pos NAND Gate