View ds1200 datasheet:

DS1200 Serial RAM Chip www.maxim-ic.com FEATURES PIN ASSIGNMENT 1024 bits of read/write memory Low data retention current for battery backup applications Four million bits/second data rate Single-byte or multiple-byte data transfer capability No restrictions on the number of write cycles Low-power CMOS circuitry 10-Pin DIP (300mil) See Mech. Drawings Section APPLICATIONS Software Authorization Computer Identification System Access Control Secure Personnel Areas Calibration Automatic System Setup Traveling Work Record 16-Pin SO (300mil) See Mech. Drawings Section PIN DESCRIPTION VCC - +5v RST - Reset DQ - Data Input/Output CLK - Clock GND - Ground VBAT - Battery (+) NC - No Connection DESCRIPTION The DS1200 Serial RAM Chip is a miniature read/wr