4004

mask

630 kB

Although the 4004 offered an outstanding ratio between price and efficiency the chip could not compete with the real computers during 1971. Since it could just manage 4 bits at once the 4004 was much slower and less powerful than a state of the art central processing unit of a computer.

Intel had been commited by Nippon Calculating Machine Corporation (later Busicom) to develop a chip family for a calculator - the Busicom 141-PF.

Four main persons were involved in this project:

Federic Faggin: developed the silicon gate MOS technology and was the head
                        of the 4004 team; he designed the complete chip layout of the
                        4000 series (and of 8008 / 8080 as well); Faggin left Intel at the
                        end of 1974 to build up a new semiconductor company - Zilog.

Stan Mazor: added some instructions to the chip architecture and designed
                   program specimen to check the feasibility of the whole chip design.
                   He was also responsible for the interface communication between
                   different departments and other contact partners.

Masatoshi Shima: designed the controller chip, its logic and the arrangement of
                            circuits on the 4004 logic

Ted Hoff: initiated the 4004 concept (instead of a chip series); proposed the
              alternative to build a complete new programmable processor unit instead
              of the chip serie demanded by Busicom; the chip should be used for
              several purposes depending on the implemented programs; he designed
              the basic architecture (CPU, RAM, ROM and I/O) and the logic.

Bob Noyce, chairman of Intel, managed to change the licence agreement between Intel and Busicom on payment of $ 60,000. Intel got the rights on the chip design and to build in the 4004 into other computers as well. In view of the starting processor industry Busicoms decision was one of the most serious management mistakes made by a company.

The 4004 is a complete 4-bit parallel central processing unit with 46 instructions. Fabricated with P-channel silicon gate MOS technology.

4001:             256 x 8 mask programmable ROM
4002:             320-bit RAM and 4-bit output port
4003:             10-bit shift register/output expander
4008/4009:     standard memory and I/O interface set
4101:             256 x 4 RAM
4201/4201A:   clock generator
4265:             programmable general purpose I/O device
4269:             programmable keyboard display device
4289:             standard memory interface
4308:             1024 x 8 mask programmable ROM and four 4-bit I/O Ports
4316A/2316A: 2048 x 8 ROM
4702A/1702A: 256 x 8 UV erasable PROM

Examples







Package

                            Miscellaneous

Overall view	Circuit board
(449 kB)	(2.2 MB)
first desktop calculator with implemented microprocessor    (backside)	consists of 4001-001, 4001-0102, 4001-0203, 4001-304 2 x 4002-1, 2 x 4003, 1 x 4004

Intel P4001	Intel P4002-1	Intel P4003	Intel C4004
2048-bit ROM with a 4-bit programmable I/O port gold leads, special coating	4-registers x 20-locations x 4-bit RAM data memory with 4-bit output port tin leads, special coating	I/O expansion chip incl. static shift register gold leads, special coating,	4-bit CPU grey traces, special coating with some cracks

Busicom sold its desktop calculators through NCR, with their brand name, in the United States. They also exported the calculators to Europe and Asia.
Busicom chose Mostek and Intel for the development of the chipset since these were the only two companies, who were experienced in silicon gate MOS technology at this time.
Busicom's original design required several chips, Intel's proposal was to reduce it to four chips. Ted Hoff suggested a general-purpose processor that could be programmed for various applications. In the beginning of 1970 Busicom agreed and signed a contract whereby Intel would develop the calculator chips for $60,000.
The 4004 was forwarded to Japan in March or April 1971. During this year Busicom was able to sell about 100,000 calculators. The introduction of the 4004 to the general market started in November 1971 after Intel had recovered the rights to use the microprocessor design and to market it for non-calculator applications.

Contents

Clock in form of a small book (polished brass); chip die of 4004 fixed in front of dial, advertise booklet

Distributed in November 1996 to celebrate the 25th anniversary of the microprocessor 4004.
After years of economic and technical war between US and Japanese microprocessor manufacturers now a Japanese company is involved into the production of this Intel memorabilia clock (see backside).