The Intersil HS-6664RH is a radiation hardened 64K CMOS PROM, organized in an 8K word by 8-bit format. The chip is manufactured using a radiation hardened CMOS process, and utilizes synchronous circuit design techniques to achieve high speed performance with very low power dissipation. On-chip address latches are provided, allowing easy interfacing with microprocessors that use a multiplexed address/data bus structure. The output enable control (G) simplifies system interfacing by allowing output data bus control in addition to the chip enable control (E). All bits are manufactured storing a logical "0" and can be selectively programmed for a logical "1" at any bit location. Applications for the HS-6664RH CMOS PROM include low power microprocessor based instrumentation and communications systems, remote data acquisition and processing systems, and processor control storage.