4-Mbit (256k x 16) static ram 256k x 16 STANDARD Sram, 45 ns, PDSO44 4-Mbit (256k x 16) static ram 256k x 16 STANDARD Sram, 55 ns, PDSO44 4-Mbit (256k x 16) static ram 256k x 16 STANDARD Sram, 55 ns, PBGA48 4-Mbit (256k x 16) static ram 4兆位56k × 16)静态ram 4-Mbit (256k x 16) static ram 256k x 16 STANDARD Sram, 70 ns, PBGA48