History and Development of Computers

Figure 1 The Vacuume Tubes

First Generation (1941-1958) The Vacuume Tubes

1. The first commercial computer (UNIVAC) delivered to Census Bureau

2. Problem: heat and burnout of tubes, also programming using punchboards / switches

3. Internal components built of vacuum tubes, and computer memory built of magnetic core

4. punched card used as supplementary storage.

5. 1957: magnetic tape introduced.

Figure 2 The ENIAC

Electronic Numerical Integrator and Computer (ENIAC)- It was produced by a partnershp between University of Pennsylvannia and the US government. It consisted of 18,000 vacuum tubes and 7000 resistors. It was developed by John Presper Eckert and John W. Mauchly and was a general purpose computer. "Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 with a memory to hold both a stored program as well as data." Von Neumann's computer allowed for all the computer functions to be controlled by a single source.

Figure 3 The UNIVAC

Universal Automatic Computer(UNIVAC I) came in the year of 1951, designed by Remington rand and collectively owned by US census bureau and General Electric. UNIVAC amazingly predicted the winner of 1952, presidential elections, Dwight D. Eisenhower.

Figure 4 TRANSISTOR

Second Generation Computers (1956-1964) The Transistor.
Internal components previously built with vacuum tubes replaced by transistor

1. Advantages of transistors: smaller, faster, more reliable, no warm-up needed

2. Machine languages (0 & 1) -> symbolic languages (L for LOAD, rather than code)

3. Symbolic languages -> High-level languages (FORTRAN `54, COBOL `59)

The invention of Transistors start of the second generation. These transistors took place of the vacuum tubes used in the first generation computers. First large scale machines were made using these technologies to meet the requirements of atomic energy laboratories. One of the other benefits to the programming group was that the second generation replaced Machine language with the assembly language. Even though complex in itself Assemly language was much easier than the binary code.

Figure 5. The INTEGRATED CIRCUIT(IC)

Third Generation Computers (1964-1971) The Integrated Circuit

Although transistors were great deal of improvement over the vacuum tubes, they generated heat and damaged the sensitive areas of the computer. The Intergreated Circuit(IC) was invented in 1958 by Jack Kilby. It combined electronic components onto a small silicon disc, made from quartz. More advancement made possible the fittings of even more components on a small chip or a semi conductor. Also in third generation computers, the operating systems allowed the machines to run many different applications. These applications were monitored and coordinated by the computer's memory.

Many transistors combined together into a very small space, forming an integrated circuit

1. A Large circuit board was replaced by an integrated circuit half the size of a fingernail.

2. IBM 360"mainframe" computer: upward-compatible design.

Figure 6. The 4004 Intel Microprocessor

Figure 7. The core i7 family

Fourth Generation: 1971 - present: Microprocessor (& Microcomputers)

A general-purpose processor on a chip; Evolutionary, not revolutionary change

1. Widespread use: watches, calculators, irons, cars, personal computers, phones

2. Mass production & further miniaturization meant 10's of millions of transistors (& other electrical components) on a single integrated circuit

Fourth Generation computers are the modern day computers. The Size started to go down with the improvement in the integerated circuits. Very Large Scale(VLSI) and Ultra Large scale(ULSI) ensured that millions of components could be fit into a small chip. It reduced the size and price of the computers at the same time increasing power, efficiency and reliability. "The Intel 4004 chip, developed in 1971, took the integrated circuit one step further by locating all the components of a computer (central processing unit, memory, and input and output controls) on a minuscule chip."

Due to the reduction of cost and the availability of the computers power at a small place allowed everyday user to benefit. First came the minicomputers, which offered users different applications, most famous of these the word processors and spreadsheets, which could be used by non-technical users. Video game systems like Atari 2600 generated the interest of general populace in the computers.

In 1981, IBM introduced personal computers for home and office use. "The number of personal computers in use more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs were being used." Computer size kept getting reduced during the years. It went down from Desktop to laptops to Palmtops. Macintosh introduced Graphic User Interface in which the users didn't' have to type instructions but could use Mouse for the purpose.

The continued improvement allowed the networking of computers for the sharing of data. Local Area Networks(LAN) and Wide Area Network(WAN), were potential benefits, in that they could be implemented in corporations and everybody could share data over it. Soon the Internet and World Wide Web appeared on the computer scene and form to the Hi-Tech revolution of 90's.