Universal Automatic Computer (UNIVAC)

In 1951, UNIVAC was developed by John Mauchly and John Presper eckert. It was known as the first commercial computer.

Electronic Discrete Variable Automatic Computer (EDVAC)

EDVAC was started to be made by John Mauchly and John Presper Eckert before 1949 but completed in 1952. It used the binary Number system.

Electronic Numerical Integrator And Calculator (ENIAC)

In 1940s. ENIAC was developed by John Mauchly and John Presper Eckert. It used vacuum tubes as main component. It used the decimal number system.

Attansoff Berry Computer (ABC)

ABC was designed by John Von Attansoff and his student Clifford Berry in 1938. It also used vacuum tubes. It was faster then the previous Computers.

Mark 1

In 1937, the first computer was developed by Howard Aiken. The concept of charles Babbage was used in it. It was 51 feet long, 8 feet tall. It used 18000 vacuum tubes as the main component.

Charles Babbage

Charles Babbage invented the differential Engine in 1822 and the analytical Engine in 1833. His concept was similar to the present concept of modern computer. That why he is known as"Father of Computer Science".

Leibniz's Calculating Machine

Leibniz's Calculatin Machine was invented by Gottfried Wilhem von Leibniz in 1671. It was the first calculator that could perform automatic addition, subtraction, division and multiplication.

qa

Pascaline

Pascaline was invented by Blaise Pascal in 1642. It is also known as Pascal's calculating machine. it was the first machine, which had capacity to find out addition and subtraction very easily. This machine is believed to be the first calculator of the world.

Slide Rule

In 1620, William Oughtred developed a device called Slide Rule. It consists of two scales in which one scale slides over the other. The slide Rule was first analog device. It was used to find out multiplication and division.

Napier's Bone

In 1617 , John Napier developed a device called Napier's Bone. It was made up of strips, bones or woods on which numbers were painted. By the combination of bones or woods, direct multiplication could be done very easily.

Abacus

The earliest calculating device was known

as Abacus. Its exact origin is unknown. It is

invented 2000 years ago. Its has 2 section:

Heaven and Earth

which are separated by beam. The heaven is

also called the upper deck, and the earth is also

called the lower deck. The Abacus was used to

perform addition and subtraction. It is still used

today in china and some other countries.

History Of Computer

• Abacus
• Napier's Bone
• Slide Rule
• Pascaline
• Leibniz's Calculating Machine
• Charles Babbage
• Mark 1
• Attansoff Berry Computer (ABC)
• Electronic Numerical Integrator and Calculator (ENIAC)
• Electronic Discrete Variable Automatic Computer (EDVAC)
• Universal Automatic Computer (UNIVAC)

Benefits and Limitation of Computers

The fact that the computers have made their impact on almost all aspects of our life in today's world can hardly be questioned. The question that you may ask here is how do you benefit from using a computer.

A Computer provides three Basic benefits:

• Speed
• Accuracy(accurate work)
• Diligence(careful hard work)

Computers work at very high speeds and are much faster than human being. The human equivalent of an average computer would be one million mathematicians working 24 hours a day. A computer rarely makes mistakes. In fact, most computer errors are cusec by human facilities. Unlike human, computers simply do not get bother or tired. The monotony of repetitive works does not affect computer. Unanticipated situation arises, computer will either produce erroneous results or abandon the task altogether. They do not have the potential to work out and alternative solution.

The Part of Computer system

Parts of computer system are :

• Hardware
• Software
• Data
• Users

Hardware

A computer's hardware consists of electronic devices; the parts you can see and touch. The term "device" refers to any pieces of hardware used by the computer, such as a keyboard, monitor,modem,mouse etc.

Software

Software consist of organized sets of instructions for controlling the computer. Some programs exist for the computer's use, to help it manage its own tasks and devices. Other programs exists for the user, and enable the computer to perform tasks for you, such as creating documents. A computer solves a wide variety of programs, but it solve the programs on it own. Its must be provide with instructions is the form of a computer program. A program is list of instructions written in a special language that computer understands. It tells the computer which operations to be perform and in what sequence to perform them.

Data

Data consists of row facts, which the computer can manipulate and process into information that is useful to people. Computerized data is digital, meaning it has been reduced to digits, or numbers. The computer stores and reads all data as number. Although computers use data in digital form, they convert data into form that people can understand, such as text, numerals, sounds and images.

Users

People are the computer's operators, or users. Some types of computers can operate without much intervention from people, but personal computers are designed specifically for used by people.

Central process Unit(CPU)

This is main part of computer which help to operate system program in computer. There are four steps that nearly all CPUs use in their operation: fetch, decode, execute, and writeback

Monitor

It is an electronic device which help us to visual display.The size of screen will be rectangular.

liquid crystal display(LCD) and Cathode ray rube(CRT) are types of Monitor and Plasma

• Cathode Ray Tube

I t hav high dynamic range and excellent colours as well as wide gamut and low black level.It can display natively. its will be large size and high power consuption.thats why its usually cheaper then LCD.

• Liquid Crystal Display

Its very compact and light and limited viewing angle.it no light and flicker depending on back light techjnology.

• Plasma

It hav high compact and light with high contrast ratios as well as excellet colour. It will be more expensive then CRT.

Parts of Computer

Here are some parts of computer.

1. Monitor
2. CPU
3. Keyboard
4. Mouse
5. Floppy drive
6. DVD/CD drive
7. Webcam
8. Head set
9. printer
10. scanner
11. Microphone

Definition of Computer

Computer is th programmable machine that can store, retrieve, and process data. Today's computers have at least one CPU that performs most calculations and includes a main memory, a control unit, and an arithmetic logic unit. Acomputer is distinguished from a calculating machine, such as an electronic calculator, by being able to store a program by the number and complexity of the operations it can perform, and by its ability to process, store, and retrieve data without human intervention.There are 2 types of computer production. These are:A>Analog Computers

B>Digital Computers

A>Analog Computers

An analog computer represents data as physical quantities and operates on the data by manipulating the quantities. It is designed to process data in which the variable quantities.The key component of the analog computer is the operational amplifier and the computer's capacity is determined by the number of amplifiers it contains.

B>Digital Computers

A digital computer is designed to process data in numerical form. its circuits perform directly the mathematical operations of addition, subtraction, multiplication, and division.Digital computers are used for reservations systems, scientific investigation, data-processing and word-processing applications, desktop publishing, electronic game, and many other purposes.

Development of Computers

Although the development of digital computers is rooted in the abacus and early mechanical calculating devices, Charles Babbage is credited with the design of the first modern computer, the "analytical engine," during the 1830s. American scientist Vannevar Bush built a mechanically operated device, called a differential analyzer, in 1930; it was the first general-purpose analog computer. John Atanassoff constructed the first semielectronic digital computing device in 1939.

First-generation computers were supplanted by the transistorized computers of the late 1950s and early 60s, second-generation machines that were smaller, used less power, and could perform a million operations per second. They, in turn, were replaced by the third-generation integrated-circuit machines of the mid-1960s and 1970s that were even smaller and were far more reliable. The 1980s and 90s were characterized by the development of the microprocessor and the evolution of increasingly smaller but powerful computers, such as the personal computer and personal digital assistant, which ushered in a period of rapid growth in the computer industry.

Functions of Computer

• A> Control Unit
• B> Arithmetic and Logical Unit(ALU)
• C> Memory
• D> Input/Output
• E> Multitasking
• F> Multiprocessing
• G> Networking and Internet

Control Unit

The control unit manages the computer's various components; it reads and decodesIt is noticeable that the sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program the program instructions, transforming them into a series of control signals which activate other parts of the computer.

Arithmetic/Logical Unit(ALU)

The set of arithmetic operations that a particular ALU supports may be limited to adding and subtracting or might include multiplying or dividing. Computers may contain multiple ALUs so that they can process several instructions at the same time.

Memory

A computer's memory can be viewed as a list of cells into which numbers can be placed.The information stored in memory may represent practically anything.The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. Computer main memory comes in two principal varieties: Random Access Memory(RAM) and Read Only Memory(ROM).RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it.ROM is typically used to store the computer's initial start-up instructions.

Input/Output

Devices that provide input or output to the computer are called peripherals.I/O devices are complex computers in their own right with their own CPU and memory.

Multitasking

While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by multitasking i.e. having the computer switch rapidly between running each program in turn. Multitasking would cause a computer that is switching between several programs to run more slowly in direct proportion to the number of programs it is running.

Multiprocessing

Some computers are designed to distribute their work across several CPUs in a multiprocessing configuration, a technique once employed only in large and powerful machines such as Super Computers, Mainframe Computers and servers. Multiprocessor and laptop computers are now widely available, and are being increasingly used in lower-end markets as a result.

Networking and Internet

Computers have been used to coordinate information between multiple locations since the 1950s.In the 1970s, computer engineers at research institutions throughout the United States began to link their computers together using telecommunications technology.