The FOUR GENERATIONS of Digital Computing

The Four Generations: The First Generation Computers (1951-1958) The Second Generation Computers (1959- 1963) The Third Generation (1963-1974) The Fourth Generation Computers (1979-Present)

The THIRD GENERATION (1963-1974)

Individual transistors were replace by integrated circuits. Magnetic tape and disks completely replace punch cards.

Magnetic core internal memories began to give way to new form, metal-oxide semiconductor (MOS) memory, which, like IC’s used silicon-backed chips. Third-generation computers were built between 1963-1974.

In the third generation, computers relied on a new technology called the integrated circuits. The integrated circuit is a single wafer or chip that can hold many transistors and electronic circuits. The invention of the transistor eliminated the need for unreliable hand-wired circuits, and allowed hundreds of circuits to be easily connected. IC’s were faster, offered improved memory and reduced the price of computers.

1959 Jack Kilby joined Texas Instruments Inc. in Dallas where he was responsible for IC development and applications. He invented the monolithic integrated circuit which is still widely used in electronics system. IC’s gave way to an entirely new era: the information age.

1968 Intel was founded by Robert Noyce. He is one of the inventors of the integrated circuit. 1969 ARPANET is set-up. ARPANET later becomes the Internet.

1972 The C programming language is developed at AT&T Bell Labs by Brian Kernighan and Dennis Ritche. The UNIX operating system, also written at Bell Labs, is rewritten using C. This later makes UNIX one of the most portable operating systems.

The FOURTH GENERATION (1979-Present)

Intel Corporation designed the first tiny computer on a chip, it was called the microprocessor. From 1974 to the present, computers have relied mainly on the microprocessor which has made computers the fastest and the most powerful they have ever been.

Microprocessor is an integrated circuit built on a tiny piece of silicon. It contains thousands, or even millions of transistors, which are interconnected via superfine traces of aluminum. The transistors work together to store and manipulate data so that the microprocessor can perform a wide variety of useful functions. Intel’s first microprocessor was the 4004. It was introduced in 1971, and contained 2,300 transistors. Today’s Pentium 4 processor contains 55 million transistors.

One of the most common tasks in microprocessor performs is to serve as the brains in inside personal computer, but deliver intelligence to countless other devices as well.

1975 Micro Instrumentation and Telemetry Systems or MITS produced the first PC. They named the computer kit Altair 8080, after the Star Trek episode, “A Voyage to Altair”. Altair 8080 was special because it made computers available to everyone. However, the kit was designed for computer experts. It also had very little memory, required assembly by the owner and had to be coded by flipping switches by hand.

1975 Altair 8080 was the first easily available microcomputer. It had 256 bytes of memory and ran a version of BASIC written by Bill Gates.

Bill Gates and Paul Allen founded the Microsoft. In 1970s, many companies sold PC kits, but the kits were confusing to use and hard to assemble.

In April 1976, Steve Jobs and Steve Wozniak founded APPLE COMPUTERS. Their aim was to built a simple yet powerful computer that the average person could unpack, plug in, and begin using immediately. Apple’s widely successful PC was the Apple II personal computer. It is the first personal computer to come in a plastic case and include color graphics.

1978 VisiCalc is released. This is the first spreadsheet program and it made microcomputers useful to business. 1979 The first microcomputer word processor, Word Star, is released.

1981 IBM enters the personal computer market with the PC. It came with DOS, an operating system based on CP/M. In an effort to save time so that it could catch the early personal computer market, IBM choose to license DOS from the then tiny Microsoft instead of writing its own operating system.

1984 IBM develops a one-million bit RAM. The Apple Macintosh debuts in 1984. It features a simple, graphical interface, uses the 8-MHz, 32-bit Motorola 68000 CPU, and has a built-in 9-inch B/W screen.

1985 The amiga introduced the world to multimedia. Amiga was the first multimedia computer, but in those days it was viewed largely as a games machine because few people grasped the importance of advanced graphics and sound combined with a multitasking system with a graphical user interface.

1985 Microsoft Windows 1.0 ships in November. Windows 1.0 looked ugly, run slowly and had very little support from the third party software developers.

1990 Windows 3 was launched. It was still 16-bit, but the user interface was completely revamped to mimic the look and feel of IBM’s as-yet unreleased OS/2 with its 3D sculpted buttons. The 640 kb memory was broken, resulting to a better performance finally giving the PC’s the chance to run large graphical applications. Multiple programs and virtual memory was also provided.

1990 Microsoft Word processor and Excel was paraded by the Microsoft which ran under windows 3.

1994 Apple announced the PowerMac family, the first Macs to be based on the PowerPC chip, an extremely fast processor co-developed with the IBM and Motorola. The PowerPC processor allowed Macs to compete with and in many cases beat, the speed of Intel’s newer processors.

1993 Intel introduces the pentium processor, a processor with 3.1 million transistors.

1995 On August 24th 1995, Windows ’95 was released.

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