- 2400 BC - The abacus, the first known calculator, is invented by the Babylonians
- 300 BC - Indian mathematician/scholar/musician Pingala invents the binary number system
- 1623 - Wilhelm Schickard of Wurttemberg (Germany) builds the first discrete automatic calculator, essentially starting the computer era
- 1671 - German mathematician Gottfried Leibniz refines the binary number system
- 1822 - Charles Babbage designs his first mechanical computer
- 1848 - British mathematician George Boole devises binary algebra, paving the way for the development of a binary computer nearly a century later
- 1890 - The 1880 census took 7 years to complete so the Census Department held a contest to find a better way, it was won by employee Herman Hollerith who went on to found the company that later became IBM
- 1939 - John Vincent Atanasoff and graduate student Clifford Berry of Iowa State University complete a prototype 16-bit adder, the first machine to calculate using vacuum tubes
- 1940 - Konrad Zuse founds the world's fist computer startup company, the Zuse Apparatebau in Berlin
- 1942 - Zuse develops the "S1" the world's first process computer
- 1945 - First "computer bug" (actually a moth) was found trapped between points at Relay #70, Panel F, of the Mark II Aiken Relay Calculator while it was being tested at Harvard University
- 1947 - The Association for Computer Machinery (ACM) is founded as the world's first scientific and educational computing society
- 1947 - The year the first game is designed for play on a Cathode Ray Tube (CRT)
- 1948 - SSEM, Small-Scale Experimental Machine (code name "Baby") is built at the University of Manchester, it is the first computer to store both its programs and data in RAM
- 1955 - Steve Jobs and Bill Gates are born
- 1958 - NASA becomes operational and the first integrated circuit is produced
- 1961 - A group of students at MIT (including Steve Russell) programs a game called "Spacewar"
- 1962 - NASA launches Mariner 1 (it subsequently goes off course during launch due to a missing "bar" in its FORTRAN software
- 1966 - Hewlett-Packard enters the general-purpose computer business with the HP-2116
- 1971 - Intel releases the 4004, the world's first commercial microprocessor
- 1971 - The computer game "Star Trek" is created by Mike Mayfield on a Sigma 7 minicomputer at MIT
- 1971 - Vietnam War veteran John Draper discovers the giveaway whistle in Cap'n Crunch cereal boxes perfectly reproduces a 2600 hertz tone; Draper builds a "blue box" that, when used with the whistle and sounded into a phone receiver, allows people to make free calls
- 1972 - The first video game console for the home market, Magnavox Odyssey, is released
- 1973 - The Xerox Alto is introduced as the first personal computer and the first to use a mouse, the desktop, and a graphical user interface
- 1975 - Don Daglow, a student at Claremont Graduate University, writes the first computer role-playing game for PDP-10 mainframes called "Dungeon" an unlicensed implementation of the role-playing game "Dungeons and Dragons"
- 1975 - The MITS Altair becomes the world's first mass-produced personal computer kit and the first to use an Intel 8080 processor
- 1976 - Seymour Cray develops the Cray-1, the first supercomputer to make vector processing practical
- 1977 - The Apple II personal computer is launched
- 1977 - Atari releases its cartridge-based console called the Video Computer System (VCS), later called Atari 2600
- 1978 - The term "hacker" is first used when boys who ran the early switchboards of Bell telephones were fired because they were misdirecting calls and listening in on conversations
- 1980 - IBM enters the personal computer market
- 1980 - Bill Gates offers to provide an operating system; Q-DOS is licensed to IBM and MS-DOS/PC-DOS is born
- 1981 - The IBM PC is released
- 1982 - The Commodore 64 is released and becomes the best-selling PC of all time
- 1982 - Time Magazine names the home computer the "Machine of the Year" or Person of the Year for that year
- 1982 - Apple Lisa is released for the retail price of $9,995
- 1982 - A program called "Elk Cloner" is the first computer virus to appear "in the wild"
- 1983 - The home computer Enterprise 128 is announced
- 1984 - Apple computer launches Macintosh, announced by a single commercial broadcast during Super Bowl XVIII
- 1990 - Microsoft introduces Windows 3.0
- 1991 - Linux is born with the following post to the Usenet Newsgroup comp.os.minix: "Hello everybody out there using minix - I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386 (486) AT clones; the post is by Finnish college student Linus Torvalds, and his hobby grew into one of the most widely used Unix-like operating systems in the world
- 1991 - Promoting OS/2, Bill GAtes says "DOS is dead;" later that year the development of DOS 5.0 leads to the permanent dropping of OS/2 development
- 1992 - The PowerPC 601, developed by IBM, Motorola, and Apple Computer, is released making it the first-generation of PowerPC processors
- 1993 - The game "Doom" is released by id Software and the PC begins to be considered as a serious game-playing machine
- 1993 - The Intel Pentium processor, invented by Vinod Dahm, is released
- 1995 - Windows 95 is launched; unlike previous versions of Windows it is an entire operating system and does not rely on MS-DOS
- 1995 - "Concept virus," the first Macro virus, is created
- 1997 - IBM's Deep Blue becomes the first computer to beat the reigning World Chess Champion Garry Kasparov in a full chess match
- 1998 - Apple announces the iMac, an all-in-one with integral 15" multiscan monitor, 24x CDROM, 2x available USB ports, 56 kbit/s modem, 2 stereo speakers, and Ethernet (and no floppy drive)
- 2000 - Microsoft launches Windows 2000
- 2000 - The "I love you" virus appears (also known as the VBS/Loveletter worm) which by 2004 had caused upwards of 10 billion dollars in damage
- 2004 - NASA Mars Rover freezes due to too many files open in flash memory
- 2005 - Apple announces they are going to use Intel processors in upcoming Macintosh computers
- 2006 - Microsoft announces their next consumer operating system, Windows VISTA; Apple Computer introduces the MacBook Pro as well as an Intel-based iMac; and so it continues...