Chronology of
Personal Computers

This document is an attempt to bring various published sources together to present a timeline about Personal Computers.

This web document is a sneak peek at a book project of mine. Since 1994, I have browsed over 1000 sources for date information related to personal computers. This brief summary includes many of the essential happenings that shaped the industry. The full text contains close to 3000 entries. I have tried to keep it open-minded and unbiased, but the annoying fact is that "the winners write the history books".

References are numbered in [brackets], which can be found at the end of this document. A number after the dot gives the page in the source.

Last updated: 2001 January 5.

1966

May

• Steven Gray founds the Amateur Computer Society, and begins publishing the ACS Newsletter. Some consider this to be the birth-date of personal computing. [208.64]

1968

(month unknown)

• Douglas C. Engelbart, of the Stanford Research Institute, demonstrates his system of keyboard, keypad, mouse, and windows at the Joint Computer Conference in San Francisco's Civic Center. He demonstrates use of a word processor, a hypertext system, and remote collaborative work with colleagues. [180.42] [185.98] [716.88] [753]

1969

(month unknown)

• Intel's Marcian (Ted) Hoff and Stan Mazor design a 4-bit CPU chip set architecture that could receive instructions and perform simple functions on data. The CPU becomes the 4004 microprocessor. [266.12] [556.9] [1038.146]
• Intel announces a 1 kilobit RAM chip, which has a significantly larger capacity than any previously produced memory chip. [9]

1971

(month unknown)

• The National Radio Institute introduces the first computer kit, for US$503. [208.66]

November

• In major trade publications including Electronic News, Intel officially introduces the MCS-4 (Microcomputer System 4-bit) microcomputer system. It is comprised of the 4001 ROM chip, 4002 RAM chip, 4003 shift register chip, and the 4004 microprocessor. Clock speed of the CPU is 108 kHz. Performance is 60,000 operations per second. It uses 2300 transistors, based on 10-micron technology. It can address 640 bytes. Initial price is US$200. Documentation manuals were written by Adam Osborne. The die for the chip measures 3x4 mm. The chip is introduced to the public in Las Vegas by Wayne Pickette. [9] [176.74] [202.165] [296] [393.6] [62] [773] [900] [953.28] [266.14] [393.6] (750 kHz [556.11]) (1972 [339.86])

1972

April

• Intel introduces its 200-KHz 8008 chip, the first commercial 8-bit microprocessor, part of the MCS-8 product family of chips. It accesses 16 KB of memory. The processor was originally developed for Computer Terminal Corporation (later called Datapoint). It uses 3500 transistors, based on 10-micron technology. Speed is 60,000 instructions per second. [9] [106.104] [208.66] [266.13] [296] [62] [556.10] [900] [953.28] [1038.150] [1064.246] (1971 [208.70] [266.xiv])

(month unknown)

• Xerox decides to build a personal computer to be used for research. Project "Alto" begins. [263.58] [266.267] [716.85]
• Canada's Automatic Electronic Systems introduces the world's first programmable word processor with a video screen, the AES 90. The computer system uses magnetic disks for storage, and a custom-built microprocessor. [615.94]

1973

(month unknown)

• Scelbi Computer Consulting Company offers the first computer kit in the U.S. using a microprocessor, the Intel 8008-based Scelbi-8H, for US$565, with 1 KB programmable memory. An additional 15 KB is available for US$2760. [9] [208.66]
• Gary Kildall writes a simple operating system in his PL/M language. He calls it CP/M (Control Program/Monitor). [266.138] (Control Program for Microcomputer [346.50]) (Control Program / Microprocessor [1076.18]) (1974 [443.433])

1974

April

• Intel releases its 2 MHz 8080 chip, an 8-bit microprocessor. It can access 64 KB of memory. It uses 6000 transistors, based on 6-micron technology. Speed is 0.64 MIPS. [9] [41] [108] [176.74] [266.30] [296] [346.19] [879.116] [953.28] (1973 [208.70]) (March [1038.150])

(month unknown)

• Gary Kildall, of Microcomputer Applications Associates, develops the CP/M operating system for Intel 8080-based systems. [9] [176.64] [258.224]

July

• Radio Electronics magazine publishes an article on building a Mark-8 microcomputer, designed by Jonathan Titus, using the Intel 8008. [208.67]

(month unknown)

• Motorola introduces its 6800 chip, an early 8-bit microprocessor used in microcomputers and industrial and automotive control devices. The 6800 was designed by Chuck Peddle and Charlie Melear. [556.11] [1038.150]

December

• Popular Electronics publishes an article in its January 1975 issue by MITS announcing the Altair 8800 computer for US$439 in kit form. It uses the Intel 8080 processor. The Altair pictured on the cover of the magazine is actually a mock-up, as an actual computer was not available. [9] [106.104] [123] [185.109] [192.3] [208.67] [218] [205.18] (US$397 [266.35] [346.19] [353.190] [415.15])

1975

February

• Paul Allen meets with Ed Roberts to demonstrate the newly written BASIC interpreter for the Altair. Despite never having touched an Altair before, the BASIC works flawlessly. [346.24] [346.257] [606.17]
• Bill Gates and Paul Allen license their newly written BASIC to MITS, their first customer. This is the first computer language program written for a personal computer. [123] [176.122] [389.28]

March

• Fred Moore and Gordon French hold the first meeting of a new microcomputer hobbyist's club in French's garage, in Menlo Park, California. 32 people meet, including Bob Albrect, Steve Dompier, Lee Felsenstein, Bob Marsh, Tom Pittman, Marty Spergel, Alan Baum, and Steven Wozniak. Bob Albrect shows off an Altair, and Steve Dompier reports on MITS, and how they had 4000 orders for the Altair. [185.110] [266.104] [301.55] [346.18] [353.200] [346.257] [930.31] (April [208.67] 266.39)

April

• Bill Gates and Paul Allen found Micro-Soft (the hyphen is later dropped). [41] (July [346.26]) (August [346.257])
• MITS delivers the first generally-available Altair 8800, sold for US$375 with 1 KB memory. [208.67] (256 bytes [266.38])

June

• MOS Technology announces the MC6501 processor for US$20 and the MC6502 for US$25. [9] [261.304] (Fall [824])

(month unknown)

• Gordon Moore revises his 1965 prediction about transistor density, from doubling every 12 months to doubling every 18 months. This becomes known as Moore's Law. [1000.20]

July

• Dick Heiser opens Arrow Head Computer Company, subtitled "The Computer Store", in Los Angeles, selling assembled Altair computers, boards, peripherals, and magazines. This is the first retail computer store in the USA. [266.185] [684.41]

(month unknown)

• IMSAI announces the IMSAI 8080 microcomputer. [346.32] [647.95]

September

• The first issue of BYTE magazine is published. [9] [266.159]

1976

(month unknown)

• MOS Technology ships the 6502 microprocessor. The 6502 was developed by Chuck Peddle. [556.11]
• MOS Technology announces the KIM-1 Microcomputer System, with 1 MHz 6502 CPU, 1 KB RAM, 2 KB ROM monitor, 23-key keypad, LED readout, cassette and serial interfaces, for US$245. [193.14] [261.304] (1975 [9])

March

• Steve Wozniak and Steve Jobs finish work on a computer circuit board, that they call the Apple I computer. [46]
• Intel introduces the 5 MHz 8085 microprocessor. Speed is 0.37 MIPS. It uses 6500 transistors, based on 3-micron technology. It supports an 8-bit bus, and operates on a single 5-volt power supply. [62] (1978 [120])

April 1

• Steve Jobs and Steve Wozniak form the Apple Computer Company, on April Fool's Day. [9] [46] [140] [218] [606.18]

June

• At the PC '76 conference at the Shelbourne Hotel in Atlantic City, Processor Technology unveils the Sol-20 microcomputer. The Sol-20 uses an Intel 8080 processor, and is sold in a kit form. [205.20] [266.116] [353.242]

July

• Zilog releases the 2.5 MHz Z80, an 8-bit microprocessor whose instruction set is a superset of the Intel 8080. [32] [202.168] (early 1975 [9]) (1975 [556.11]) (1975 December [346.257] [1038.150])

November

• ComputerLand opens a pilot store in Hayward, California, as a retail outlet and a training facility for franchise owners. [266.194] [346.258] [548.433]

December

• Michael Shrayer completes writing the Electric Pencil word-processing program for microcomputers. [9] [266.148] [346.258] [662.33]

1977

January

• Commodore Business Machines first shows a prototype PET computer at the Winter Consumer Electronics Show. [713.32]

February

• Bill Gates and Paul Allen sign a partnership agreement to officially create the Microsoft company. [123]

April

• Commodore Business Machines shows its PET 2001 computer at the West Coast Computer Faire. The PET includes a 6502 CPU, 4 KB RAM, 14 KB ROM, keyboard, display, and tape drive, for US$600. The computer shown is a one-off prototype. [9] [266.182] [346.46] [445.256] [713.30] [747.74] (US$800 [176.54] [190.81]) (March [41]) (June [624.172])
• Apple Computer introduces the Apple II at the West Coast Computer Faire. The computer features a 6502 CPU, 4 KB RAM, 16 KB ROM, keyboard, 8-slot motherboard, game paddles, graphics/text interface to color display, and built-in BASIC, for US$1300. It is the first personal computer with color graphics. [9] [41] [46] [120] [140] [176.54] [203.7] [266.182] [346.47] [593.350] (March [185.114]) (July [716.234])

August

• Radio Shack (a division of Tandy Corp.) announces the TRS-80 microcomputer, with Z80 CPU, 4 KB RAM, 4 KB ROM, keyboard, black-and-white video display, and tape cassette for US$600. [9] [195.49] [202.198] [319.43] [548.413] [862.14] (US$300 [266.198]) (June [41]) (1978 [205.24])

1978

June

• Intel introduces the 4.77 MHz 8086 microprocessor. It uses 16-bit registers, a 16-bit data bus, and 29,000 transistors, using 3-micron technology. Price is US$360. It can access 1 MB of memory. Speed is 0.33 MIPS. Later speeds included 8 MHz (0.66 MIPS) and 10 MHz (0.75 MIPS). [108] [176.74] [177.102] [216.22] [296] [447.144] [465.25] [477.124] [540.64] [62] [690.94] [879.116] (April [346.61]) (1979 [120])

December

• Epson announces the MX-80 dot matrix printer. [9]
• Atari announces the Atari 400 and 800 personal computers, both featuring the 6502 microprocessor. The Atari 800 was code-named "Colleen" during development. [9] [231.83] [252.50] (1979 [624.178])

1979

May

• Software Arts demonstrates VisiCalc at the 4th West Coast Computer Faire. Dan Bricklin and Bob Frankston wrote it during 1978-79, under the company name Software Arts, under contract to Personal Software. [9.202] [80.126] [176.64] [203.9] [218] [266.xv] [346.102] (June [41])

June

• Apple Computer introduces the Apple II Plus, with 48 KB memory, for US$1195. [46] [200.1] [218] [593.350]
• Intel introduces the 4.77 MHz 8088 microprocessor. It was created as a stepping stone to the 8086, as it operates on 16 bits internally, but supports an 8-bit data bus, to use existing 8-bit device-controlling chips. It contains 29,000 transistors, using 3-micron technology, and can address 1 MB of memory. Speed is 0.33 MIPS. A later version operates at 8 MHz, for a speed of 0.75 MIPS. [296] [477.124] [536.502] [540.64] [203.12] [62] [879.116] [900] [947.102] (February [177.102]) (1981 [120])
• Texas Instruments introduces the TI-99/4 personal computer, for an initial price of US$1500. It uses the TI 9940 16-bit microprocessor. [9] [202.209] (late 1979 [714.135]) (US$1150 [246.81])
• MicroPro International releases the WordStar word processor, written by Rob Barnaby. It is made available for Intel 8080A Zilog Z-80 based CP/M-80 systems. [266.153] [346.259] [862.202] [1033.171] (written by Seymour Rubenstein [176.64])

September

• Motorola introduces the 68000 16-bit microprocessor. It uses 68,000 transistors, giving it its name. [176.75] [423.136] (1980 [120])

October 17

• Personal Software releases VisiCalc for the Apple II, for US$99. [46] [140] [218] [266.230] [346.102] [618.70] [1033.171] [1056.327] (November [120])

1966-1979

1980-1984

1985-1989

1990-1994

1995-2001

Check my list of references for details on specific events.
Also check my list of other timelines.