2700 256-Bit Low-Power Schottky Bipolar RAM* (AMD*) (Not Dynamic!) I looked it up in the 1984 data book: Am27LS00/01 Series. It's organised as 256*1 bit. Pin-layout: a1 vcc a0 a2 /cs a3 /cs d1 /cs /we /d0 a7 a4 a6 gnd a5