1971 - Microprocessor Condenses CPU Function onto a Single Chip
Intel engineers, led by Federico Faggin, implement Ted Hoff’s architectural concept to create the i4004 single-chip implementation of a computer central processing unit (CPU), now called a micro-processor unit or MPU.
Gold interconnects highlight the i4004 layout complexity
Courtesy of: Intel Corporation.
By the late-1960s, designers were working to integrate the key functions of a computer onto a handful of MOS LSI chips. After designing the 3800 single-chip 8-bit arithmetic logic unit at Fairchild, Lee Boysel enhanced its functionality into the AL-1 “computer slice” at Four-Phase Systems Inc in 1969. In 1970 Steve Geller and Ray Holt of Garrett AiResearch implemented the F-14A Central Air Data Computer on six AMI metal-gate MOS chips.
The term microprocessor was coined to describe the 4004 “CPU on a chip” conceived by Ted Hoff and Stan Mazor at Intel in 1971. Assisted by Hal Feeney and Masatoshi Shima, Federico Faggin used silicon gate MOS technology (1968 Milestone) to squeeze the 2300-transistors of this 4-bit microprocessor unit (MPU) into a 16-pin package. Faggin also led the design of Intel's first 8-bit MPU (8008) in 1972. Support from EPROMs, (1971 Milestone) and development system tools in 1974 established the 4500-transistor successor to the 8008, the 8080, as the first MPU produced in high volume. Early 1974 also saw the introduction of the widely successful M6800 8-bit architecture by Tom Bennett at Motorola.
By the mid-1970s many vendors offered enhanced 8-bit architectures, with Zilog's Z-80 being the most enduring. A low-cost 6800 clone by MOS Technology (6502) enabled personal computers and games from Apple, Atari, Commodore and others. Two 1975 devices that presaged important later trends included a CMOS MPU from RCA and John Cocke’s 801 RISC chip at IBM. General Instrument, National, TI, and Zilog introduced 16-bit MPU families but none matched the success of Intel’s 8086/8088 (introduced 1976) architecture in the IBM Personal Computer or Motorola's 68000 (1979) in the Apple Macintosh.
Boysel, Lee. “Adder on a Chip: LSI Helps Reduce Cost of Small Machine.” Electronics (March 18, 1968) pp. 119-123.
Boysel Lee L. & Murphy, Joseph P. "Four-Phase LSI Logic Offers New Approach to Computer Designers," Computer Design (April 1970) pp. 141-146.
Faggin, F. and Hoff, M.E. "Standard parts and custom design merge in four-chip processor kit," Electronics (April 24, 1972) pp. 112-116.
Faggin, F., Shima, M., Hoff, M.E., Feeny, H., Mazor S. "The MCS4 - An LSI micro-computer system," IEEE 1972 Region Six Conference, IEEE Press (1972) pp. 8-11.
Hoff, Jr., M. E., Mazor, Stanley, Faggin, Federico. “Memory System for a Multi-Chip Digital Computer” U. S. Patent 3,821,715 (Filed January 22, 1973. Issued June 28, 1974).
Altman, Laurence "Single Chip Microprocessors open up a New World of Applications," Electronics (April 18, 1974) pp. 81-87
Noyce, R., and Hoff, M. "A History of Microprocessor Development at Intel," IEEE Micro, Vol. 1, No. 1 (1981) pp. 8-21
Augarten, Stan. “The First Microprocessor - 4004,” State Of The Art: A Photographic History of the Integrated Circuit. (New Haven & New York: Ticknor and Fields, 1983) pp.30, also see pp. 34, 36, 40, 44, 46, and 48
Shima, Masatoshi. Electrical Engineer, an oral history conducted in 1994 by William Aspray, IEEE History Center, Rutgers University, New Brunswick, NJ, USA
Malone, Michael S. The Microprocessor: A Biography. (New York: Springer-Verlag TELOS, 1995) pp.10-15
Faggin, F.; Hoff, M.E., Jr.; Mazor, S.; Shima, M. “The history of the 4004,” IEEE Micro Vol. 16, Issue 6 (December 1996) pp: 10–20
Aspray, William. “The Intel 4004 Microprocessor: What Constituted Invention?” IEEE Annals of the History of Computing, Vol. 19, No. 3 (July-September 1997) pp. 4-15
Mazor, Stanley. "Intel 8080 CPU Chip Development," IEEE Annals of the History of Computing, Vol. 29, No. 2 (Apr-June, 2007) pp. 70-73