The SN74ACT72211L, SN74ACT72221L, SN74ACT72231L, and SN74ACT72241L are constructed with CMOS dual-port SRAM and are arranged as 512, 1024, 2048, and 4096 9-bit words, respectively. Internal write and read address counters provide data throughput on a first-in, first-out (FIFO) basis. Full and empty flags prevent memory overflow and underflow, and two programmable flags (almost full and almost empty) are provided.