Fundamentals of IT

What is a Computer?

Computer is a man made programmable electronic machine which can store, retrieve and process data into information according to the instructions given.

Data + Instructions – Information

What is Data?

Raw facts that are to be processed

What is Information?

Processed Data with meaning

Characteristics of the Computer

Comparative to human

Advantages

1 Speed

2 Accuracy GIGO Garbage in garbage out

3 Diligence free from tiredness

4 Versatility could perform different tasks

5 Power of remembering

Disadvantages

No IQ

No feelings

History of Computer.

Mechanical Age

• Abacus – First man made computing device is ABACUS It is a calculating device (3000 BC) Small beads are arranged on vertical rods

This is still used in China. Russia & Far East

• Pascaline - Mechanical adding machine (1642) Pascal used wheels to move beads

• Von Leibnitz made improvements in the Pascals machine in 1674. Addition, Subtraction, Multiplication, Division could be done

• Joseph Jacquard introduced the punch card system for the weaving industry(1800)

• Charles Babbage (Father of Computers) English mathematician in 19th century Using the punch card system he invented the analytical engine. This was not successful as the mathematics knowledge at that time was not adequate. This machine could store 1000, 50 digit numbers for calculations & decisions.He called this the analytical engine (1830s)

He also invented the Difference Engine

.Ada Love lace-World's first programmer (1800s)

Hollerith - tabulating machine (1890s)He introduced a system to process census data in United States in 1890 using punched card system

• The code developed by Hollerinth is called the Hollerinth code

ELECTRONIC AGE

1900 - 1945

Howard Aiken using Babbages concept invented MARK I a calculator in 1944. MARK I used a typewriter as the input & punched cards as the

output. Weighed 15 tons.

1 st generation (1946)

ENIAC (Electronic Numerical Integrator & Computer) was the first electronic digital computer built in 1946. ENIAC used the vacuum Tube technology.

In 1950 Remington Rand manufactured the

UNIVAC 1 (Universal Automatic Calculator) first machine to use magnetic medium for input and output.

In 1957 IBM (International Business Machine) Corporation developed IBM 704 which could perform 100000 calculations per second.

2 nd generation (1950)

Late 1950 transistors were invented and replaced vacuum tubes. It could perform 200,000 – 250,000 calculations per second.

Tapes were used for output.

3 rd generation ( 1959 1965 )

Integrated circuits replaced the transistors. Magnetic discs were used for storing.

4 th generation (1971)

Integratcd circuits were coupled and formed LSI (Large Scale Integration) and VLSI ( Very Large Scale Integration) which formed microchips. Multi-programming and virtual storage memory were introduced.

5^th generation (1980)

These computers operated at a speed of 3 to 5 million calculations per second.