It is here that the processor is first referred to as COSMAC, for COmplementary-Symmetry-Monolithic-Array Computer. It goes on to note that an effort to reduce the processor to a two-chip implementation with deliveries in COS/MOS in 1974. A 1973 lab report refers to a "prototype" being delivered in 1972, but this is likely referring to the original TTL implementation. Įventually, the company became interested in the system and began adapting it to their newly introduced COS/MOS fabrication system. Some of the skepticism displayed by management may have had to do with the company's recent sale of their mainframe computer business to Sperry Rand with a huge writedown. Robert was more interested in building the media side of the company while dating recording stars, ignoring RCA Laboratories in spite of a number of industry-leading developments taking place there. This was shortly after David Sarnoff had retired and handed the CEO role to his son, Robert Sarnoff. Weisbecker demonstrated the machine to RCA management throughout this period, but there was little interest at first. When RCA entered the game console business in the later 1970s, these games were burned to ROM cartridge form, and Joyce became the first known female commercial videogame developer. This included several games, which were ported to later machines based on the COSMAC. Weisbecker's daughter, Joyce Weisbecker, was immediately drawn to the system and began writing programs for it. Weisbecker added new features continually and by 1972 it had gained a character generator and the ability to load and save programs on cassette tapes. The result, which he called FRED, ostensibly for Flexible Recreational Educational Device, was packaged into a box that was not unlike the Altair 8800 of a few years later, with toggle switches on the front panel for input, lamps for output, and later adding a hex pad keyboard. The design was running in October 1971, containing 100 chips spread over multiple circuit boards. Other parts, switches and lamps and such, he had to buy from Radio Shack, deliberately spreading his purchases around four stores so no one would ask him why he was buying so many parts. īeginning in 1970, Weisbecker began the design of a small machine using RCA transistor-transistor logic (TTL) ICs to construct the processor. Inexpensive…microcomputers could open up vast new markets. Now, microcomputers afford some of us the opportunity to return to simpler systems. In 1974 he described the possibilities in an IEEE Computer article:įor 20 years computer hardware has become increasingly complex, languages more devious, and operating systems less efficient. The technology of the era made small embedded computers impossible, but the introduction of the integrated circuit (IC) in the 1960s changed things dramatically. Joseph Weisbecker had long been fascinated with the potential for computers in the home, having stated as early as 1955 that he expected they would one day be built into practically every device. There are also some minor pin function changes, but the line continues to be produced in its original 40-pin dual in-line package (DIP) format. Some features are also lost, like the DMA auto-boot loader functionality. Successors to the 1802 are the CDP1804, CDP1805, and CDP1806, which have an extended instruction set, other enhanced features (like on-chip RAM and ROM, and built-in timer), with some versions running at faster clock speeds, though not a significant speed difference. These remain in production as of 2022, and as of 2008 continued to be produced by Renesas (formerly Intersil). RCA also produced radiation hardened versions, which found use in the aerospace field. This allowed it to run at lower power settings and even be stopped completely in addition it would run cooler and not generate as much heat as NMOS chips. In contrast to most designs of the era, which were fabricated using the NMOS process, the COSMAC was implemented in CMOS form and used static logic. Jerry Herzog led the design of the single-chip version, which sampled in 1975 and entered production in 1976. RCA began development of the CMOS version of the processor design in 1973, sampling it in 1974 with plans to move to a single-chip implementation immediately. The processor design traces its history to an experimental home computer designed by Joseph Weisbecker in the early 1970s, built at his home using TTL components. The 1802 represented the majority of COSMAC production, and today the entire line is known simply as the RCA 1802. The first production model was the two-chip CDP1801R and CDP1801U, which were later combined into the single-chip CDP1802. It is historically notable as the first CMOS microprocessor. The COSMAC (Complementary Symmetry Monolithic Array Computer) is an 8-bit microprocessor family introduced by RCA.
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