The AT27C256R-70PU is a 256K (32K x 8bit) one time programmable read only memory (OTP EPROM) device in 28 pin DIP package. This low power, high performance, 262144bit memory requires only one 5V power supply in normal read mode operation. Any byte can be accessed in less than 70ns by eliminating need for speed reducing WAIT states on high performance microprocessor systems. The Atmel scaled CMOS technology provides low active power consumption and fast programming. The AT27C256R-70PU allows firmware to be stored reliably and to be accessed by the system without the delays of mass storage media. It has additional features to ensure high quality and efficient production use. The rapid programming algorithm reduces time required to program the device and guarantees reliable programming.