Introduced in 1971, the Kenbak-1 is generally considered to be the world's first personal computer. Designed by John V. Blankenbaker, the Kenbak-1 included 256 bytes of memory, ran at an operating speed of about 1MHz, and sold for $750. Unlike many earlier machines it was a true stored-program (Von Neumann) computer. Unfortunately for Blankenbaker, the world wasn't quite ready for the personal computer. After selling only 40 machines, the Kenbak Corp. was forced to go out of business in 1973.

According to the Oxford English Dictionary, the word "computer" was first used to describe a mechanical calculating device in 1897. Although the word existed previously, it had been used to describe "a person who computes or performs calculations."

In 1981, Osborne Computer introduced the world's first portable computer -- the Osborne I. Weighing almost 24 pounds, the Osborne I wasn't very portable by today's standards, but it was light enough to carry and could fit under an airplane seat. The Osborne I, which sold for $1,795, came with a 5-inch display, modem port, two 5 1/4 floppy drives, battery pack, and 64 kilobytes of memory.

During the 1970s several computer engineers working at various research institutions came up with the idea of using telecommunications technologies to link their computers together. This effort, the forefather of the modern Internet, was known as the ARPANET (Advanced Research Projects Agency Network). Originally, the ARPANET consisted of only four nodes located at the University of California - Los Angeles, the University of California - Santa Barbara, the Stanford Research Institute, and the University of Utah. The first ARPANET link was established between UCLA and SRI on November 21, 1969. By December 5, 1969, the entire 4-node network was connected.

In May 1997, a chess-playing computer called Deep Blue defeated chess grandmaster Garry Kasparov, making it the first computer to defeat a world champion chess player under standard chess tournament time controls. In 1996, a previous version of Deep Blue had defeated Kasparov in a single game, but had lost the match by a score of 4-2.

In 1963, Douglas Engelbart of the Stanford Research Institute invented the computer mouse, a handheld pointing device for computers. One of several experimental pointing devices developed by Engelbart for his ON-Line System (NLS), it was also called the "bug," but "mouse" became more popular because the cord on early models resembled a rodent's tail. An improved version of the mouse was developed by Bill English at Xerox PARC during the early 1970s which replaced the external wheels of the original model with a single ball, resembling an inverted trackball, that could rotate in any direction. Even the popular trackball, however, was done away with in the optical mouse, a device which utilized an optical sensor to detect movement. In 2004, Logitech introduced the first laser mouse, claiming a 20x increase in accuracy compared to the conventional optical mouse.

More of an empirical observation than an actual law, Gordon E. Moore, the co-founder of Intel, first stated in 1965 the fact that computers/computing devices have tended to double in capacity/complexity every 18 to 24 months since 1900. This observation has come to be called "Moore's Law."

At the time of its original release, Microsoft's Windows 98 operating system contained approximately 18 million lines of code. In comparison, Windows 3.1 contained about 3 million lines of code; Windows 95 contained about 15 million lines of code; and Windows 2000 contained somewhere between 35 million and 60 million lines of code, depending on what source you want to believe.

The Cray I was the first commercially successful vector processor. The fastest machine of its day, the Cray I was capable of performing 166 million floating-point operations per second. This impressive (at the time) speed was due partly to its shape, a "C", which reduced the length of wires and therefore the distance signals needed to travel. At 58 cubic feet, the Cray I weighed approximately 5,300 lbs.

Apple Computer launched its new Macintosh computer with a $1.5 million commercial during the 1984 Super Bowl. The ad played on the Big Brother theme of George Orwell's 1984, depicting Big Brother meeting his demise thanks to the powerful Macintosh personal computer. The first successful mouse-driven computer with a graphic interface, the Macintosh also boasted WYSIWYG (What You See Is What You Get) word processing, a much anticipated innovation. Containing many of the most popular features of Apple's previous (and very expensive) Lisa computer, the Macintosh sold for a much more affordable $2,500.