Early computers: The Abacus\nPerhaps the oldest continuously used calculating tool aside from fingers, the abacus is a masterpiece of power and simplicity. Abacuses were widely used in Asia and Europe for centuries, and remain common today.\nThe 50 Greatest Gadgets of the Past 50 Years\nPunch cards: The Herman Hollerith Machine\nNothing stimulates creativity like a good crisis. The U.S. Constitution requires a census every decade. That was manageable in 1790 with fewer than 4 million Americans to tally. Not so simple a century later, with 63 million. Estimates warned that the 1890 census wouldn't be finished before the 1900 census began. The government's answer? A contest to devise a solution. Herman Hollerith won. He suggested recording data on punched cards, which would be read by a tabulating machine.\nPhotos courtesy Computer History Museum\nAnalog computers: Nordsieck's Differential Analyzer\nUsing $700 worth of surplus World War II supplies, Arnold Nordsieck assembled an analog computer in 1950. It was modeled on differential analyzers built since the 1930s but with key differences. For instance, Nordsieck's computer used electrical connections instead of mechanical shafts. And he set himself the priorities of "convenience and simplicity portability, and economy." His device's small size and straightforward engineering satisfied the first three requirements. Its $700 price tag satisfied the fourth.\nBirth of the computer: The ENIAC\nIn 1942, physicist John Mauchly proposed an all-electronic calculating machine. The U.S. Army, meanwhile, needed to calculate complex wartime ballistics tables. Proposal met patron. The result was ENIAC (Electronic Numerical Integrator And Computer), built between 1943 and 1945, it was the first large-scale computer to run at electronic speed without being slowed by any mechanical parts. For a decade, until a 1955 lightning strike, ENIAC may have run more calculations than all mankind had done up to that point.\nEarly computer companies: The Univac\nComputing burst into popular culture with UNIVAC (Universal Automatic Computer), arguably the first computer to become a household name. A versatile, general-purpose machine, UNIVAC was the brainchild of John Mauchly and Presper Eckert, creators of ENIAC. They proposed a statistical tabulator to the U.S. Census Bureau in 1946, and in 1951 UNIVAC I passed Census Bureau tests. Within six years, 46 of the million-dollar UNIVAC systems had been installed with the last operating until 1970.\nMainframes: IBM System \/360\nAt one time a computer was simply a computer. When, in the mid-1960s, companies such as Digital Equipment Corp. and Data General began marketing their mini-computers, the term "mainframe" (also known as "big iron") arose to designate the larger general purpose machines provided by firms such as IBM, Univac, etc. While there is no exact definition, it usually implies a machine capable of large-scale computing tasks demanding high availability, high I\/O rates, large storage for online databases, and sometimes the ability to run multiple operating systems simultaneously.\nThe first disk drive: The IBM RAMAC 350\nComputers hold thousands of data records. Imagine if finding the one you wanted required starting with the first, then going through them in order. High speed, random access memory plucking information from storage without plodding through sequentially is essential to the way we use computers today. IBM's RAMAC (Random Access Method of Accounting and Control) magnetic disk drive pioneered this ability. The RAMAC 350 storage unit could hold the equivalent of 62,500 punch cards: 5 million characters.\nSupercomputers: The Cray-1 Supercomputer\nFeaturing a central column surrounded by a padded, circular seat, the Cray-1 looked like no other computer. And performed like no other computer. It reigned as the world's fastest from 1976 to 1982. Its distinctive design reflected Seymour Cray's innovative engineering solutions and theatrical flair. The round tower minimized wire lengths, while the distinctive bench concealed power supplies. Densely packed integrated circuits and a novel cooling system reflect Cray's attention to "packaging and plumbing."\nWhat Makes IBM Watson So Smart?\nWicked Cool Man vs. Machine Moments\nMinicomputers: DEC's PDP-8\nDigital Equipment Corp.'s PDP-8 was the first commercially successful minicomputer. Released in March 1965, more than 50,000 units were sold, even though it had not originally been intended as a general-purpose machine. The first PDP-8 model was about the size of a mini-refrigerator and used diode-transister logic on flip chip cards. The second model was a desktop computer that used one-bit digital circuit, that was much slower than the original, but less expensive.\nDigital logic: Moore's Law\nIn an article titled "Cramming more components onto Integrated Circuits" in Electronics magazine, R&D Director Gordon Moore predicted that the number of transistors on a silicon chip would increase from 50 in 1965 to 65,000 by 1975. "Moore's Law," as it became known, created a yardstick against which companies would measure their technology progress for more than 45 years.\nInput\/output: Xerox Alto\nA mouse. Removable data storage. Networking. A visual user interface. Easy-to-use graphics software. "What You See Is What You Get" (WYSIWYG) printing, with printed documents matching what users saw on screen. E-mail. Alto, for the first time, combined these and other now-familiar elements in one small computer. Developed by Xerox as a research system, the Alto marked a radical leap in the evolution of how computers interact with people, leading the way to today's computers. (Also see Xerox PARC turns 40: Marking four decades of tech innovations)\nComputer graphics, music and art: The Utah Teapot\nComputers manipulate data. So, how do you get them to generate images? By representing images as data. Martin Newell at the University of Utah used a teapot as a reference model in 1975 to create a dataset of mathematical coordinates.\nComputer graphics, music and art: The Utah Teapot graphic\nFrom that original image Newell generated a 3D "wire frame" defining the teapot's shape, adding a surface "skin." For 20 years, programmers used Newell's teapot as a starting point, exploring techniques of light, shade and color to add depth and realism.\nComputer games: Pong\n"The machine is broken." That terse message summoned Al Alcorn to Andy Capp's bar in Sunnyvale two weeks after Alcorn had installed the Pong arcade game. Pong's problem? Popularity. Its milk carton coin-catcher was jammed with quarters.\nPong heralded a gaming revolution. Mechanical arcade games like pinball had appeared the late 1800s. Pong, designed by Alcorn for Atari in 1972, launched the video game craze that transformed and reinvigorated the old arcades and made Atari the first successful video game company.\nPersonal computers: The IBM PC\nIBM introduced its PC in 1981 with a folksy advertising campaign aimed at the general public. Yet, the IBM PC had its most profound impact in the corporate world. Companies bought PCs in bulk, revolutionizing the role of computers in the office and introducing the Microsoft Disk Operating System (MS DOS) to a vast user community. When it debuted in 1977, the Apple II was promoted as an extraordinary computer for ordinary people. The user-friendly design and graphical display made Apple a leader in the first decade of personal computing. Unlike the earlier Apple I, for which users had to supply essential parts such as a case and power supply, the Apple II was a fully realized consumer product. Design and marketing emphasized simplicity, an everyday tool for home, work or school.\nMobile computing: Palm Pilot\nLaunched in 1996, the Palm Pilot was the first generation of personal digital assistants (PDAs) created by Jeff Hawkins, Donna Dubinsky and Ed Colligan, who founded Palm Computing. The first Palms had 128KB or 512KB of RAM, no external ports and no backlighting. They used version 1 of the Palm operating system. Later models allowed upgrades to 1MB of internal RAM.\nSlideshow: A Palm Technology Timeline\nSlideshow: From Palm Pilot to Palm Pre: A Brief History of Palm's Handhelds\nNetworking and the Web: Spaghetti wires\nAT&T designed its Dataphone, the first commercial modem, specifically for converting digital computer data to analog signals for transmission across its long distance network. Outside manufacturers incorporated Bell Laboratories' digital data sets into commercial products. The development of equalization techniques and bandwidth-conserving modulation systems improved transmission efficiency in national and global systems.