History of Computers

Early Calculating Devices

• 3000 BC: People began to use an abacus for calculations.

• The standard abacus can be used to perform addition, subtraction, division, and multiplication

Napier's bones

• Napier's bones is a manually-operated calculating device created by John Napier in 1617 for calculation of products and quotients of numbers.

• 1642: Blaise Pascal made a mechanical calculator for addition and subtraction for his father to calculate taxes. These calculator that is called Pascaline was well suited for the addition however, the nonreversible mechanism required a special technique for subtraction.

Pascaline

• 1842: Charles Babbage made a machine called a Difference Engine that could solve complex problems like logarithmic and trigonometric functions.

Difference Engine

• 1890: Hermann Hollerith designed a computer that used punched cards.

• A punched card is a piece of stiff paper that contains digital information represented by the presence or absence of holes in predefined positions.

Punch cards

• 1939: John Vincent Atanasoff developed the first electronic digital computer (Atanasoff–Berry Computer). The main ideas used in the ABC included binary math and Boolean logic to solve up to 29 simultaneous linear equations. The ABC had no central processing unit (CPU) but was designed as an electronic device using vacuum tubes for digital computation. It also used separate regenerative capacitor memory, a process still used today in DRAM memory.

Atanasoff–Berry Computer(ABC)

• The first electronic computer was called the ENIAC (Electronic Numerical Integrator And Calculator)(Giant, huge Brain). It was built at the University of Pennsylvania in 1943, and it was used for military calculations, for weather forecasting, and for atomic energy calculations.

• It weighed 30 tons and filled a big room. At 11:45 PM on October 2, 1955, ENIAC was shut down.

ENIAC

ENIAC

• Dr. John Von Neumann invented a technology for program storage at the University of Princeton in 1945. This technology allowed a computer to store a program in memory. People could change the program for different purposes. Dr. John Von Neumann’s computer made it possible to develop the computers we use today

• John Von Neumann described a computer architecture in which data and program memory are mapped into the same address space (stored program technique). This group of machines included EDVAC and UNIVAC, the first commercially available computers.

• 1958: Seymour Cray started to use transistors in computers. He designed a series of computers that were the fastest in the world for decades and founded the company Cray Research which built many of these machines. Cray is called “the father of supercomputing.”

• 1964: IBM used integrated circuits in the IBM 360 computer. It was the first family of computers making a clear distinction between architecture and implementation.

Some Other Important Inventions in the History of Computers

• 1971: Intel introduced the first microprocessor (Intel 4004). It was a 4-bit CPU. Today’s 64-bit microprocessors are still based on similar designs.

• 1975: The first microcomputer, called the Altair 8800, was introduced by MITS (Micro Instrumentation and Telemetry Systems). The MITS Altair 8800 was based on a 2 MHz Intel 8080 with 256 bytes standard RAM. User interface was through the octal front panel switches.

Some Other Important Inventions in the History of Computers

• 1981: IBM introduced its first PC, IBM 5150. The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes of memory, expandable to 256k. The PC came with one or two 160k floppy disk drives and an optional color monitor. The price tag started at $1,565.

• 1984: Apple introduced the first Macintosh, Macintosh 128K. It was the first commercially successful personal computer to feature a mouse and a graphical user interface rather than a command line interface.

Some Other Important Inventions in the History of Computers

The Main Periods in the History of Computers

• The electronic computer industry has developed faster than any other industry in history.

• The history of computers has five main periods. They show how the technology that computers use for processing data has changed and developed.

1st GenerationVacuum Tubes (1930–1958)

• The first computers used vacuum tubes to make calculations. A vacuum tube is a device used to amplify, switch, modify, or create an electrical signal by controlling the movement of electrons in a low-pressure space. It looks and behaves like a light bulb. It generates a lot of heat and has a tendency to burn out.

1st GenerationVacuum Tubes (1930–1958)

• The ENIAC was a vacuum tube computer. It weighed over thirty tons and consumed 200 kilowatts of electrical power. It had around 18,000 vacuum tubes that constantly burned out.

2nd GenerationTransistors (1959)

• Transistors replaced vacuum tubes because they were smaller, faster, and more reliable and used less energy. The transistor is considered by many to be the greatest invention of the twentieth century. It is the key active component in practically all modern electronics.

2nd GenerationTransistors (1959)

• Invitation of the transistor made it possible to produce integrated circuits, make personal computers, and fly space crafts and satellites.

3rd GenerationIntegrated Circuits (1965)

• Integrated circuits (microchips) use semiconductors to make complex circuits for data processing. Their invention was a big development for the computer industry. Big boards with transistors that took up a lot of space were replaced with small boards that reduced the size of computers and made them more reliable and less expensive.

4. Microprocessors (1971)

• A microprocessor incorporates most or all of the functions of a central processing unit (CPU) on a single integrated circuit. The computer company Intel introduced its first microprocessor in 1971. It was a 4-bit processor and was used for electronic calculators. Microprocessors allow computers to perform more accurate operations in less time.

4th GenerationMicroprocessors (1971)

• A microprocessor may contain millions of transistors. An AMD dual-core Athlon Processor has 233 millions transistors, and an Intel Pentium D has 230 million transistors.

5th GenerationPersonal Computer (1981)

• The computer company IBM introduced its first personal computer (PC), called the Datamaster, in 1981. PCs are made for individual use, and are intended to be operated directly by end users, with no intervening computer operator.