Bipolar RAMs in High Speed Applications
Tech Talk: Bipolar RAMs in High Speed Applications
Static random access memory (SRAM) chips built with the bipolar IC process became practical for high-speed computer applications in the mid-1960s.
Scientific Data Systems and Signetics cooperated to produce an 8-bit RAM for the Sigma 7 scientific computer in 1965. That same year, IBM Components Division designed a 16-bit, system-protect memory array for the System 360 Model 95. In 1966, Transitron built a 16-bit scratchpad memory for the Honeywell Model 4200 minicomputer, which became the first widely second-sourced RAM.
With IBM’s first all-semiconductor memory machine, the System 370 Model 145 announced in October 1970, the company’s designs graduated to 64-bits for the cache memory and 128 bits for the main memory. In 1970, Fairchild built memory systems for the ILLIAC IV supercomputer using 256-bit chips.