Computer Skills Preparatory Year 2011-2012 Presented by: L. Obead Alhadreti

Computer Skills

Preparatory Year

2011-2012

Presented by:L. Obead Alhadreti

Lecture 1 - Outline What is a COMPUTER? The history of Computers Types of Computers

What is a COMPUTER?

Computer: is simply a programmable machine that receives input, processes data, stores data, and produces output.

Input process store output

History of Computers

The development stages of the computer can be divided into:

The Early Days: Up to 1940 The Birth of Computers: 1940–1950 The Modern Era: 1950 to the Present

History of Computers The Early Days: Up to 1940

1. Abacus: a simple counting aid, may have been invented in Babylonia (now Iraq) in the fourth century B.C.

2. Arabic numeral: are introduced to Europe in the eighth and ninth centuries. Introduced the concepts of the zero and fixed places for tens, hundreds, thousand, etc., and greatly simplified mathematical calculations.

History of Computers

3. Binary system: developed by Gottfried Leibniz in 1600s, is of critical importance for the development of modern computers.

4. Pascal's calculator: the French philosopher and mathematician Blaise Pascal invented a calculating device that would come to be called the "Adding Machine".

History of Computers

5. Difference engine: a mechanical calculator developed by Charles Babbage in 1823. Did addition, subtraction, multiplication, and division to 6 significant digits.

6. Analytic engine : considered the first computer ever. A general-purpose, automatic mechanical computer, developed by Charles Babbage in 1833.

History of Computers The Birth of Computers: 1940–1950 Development of electronic, general-purpose

computers, was fueled in large part by needs of World War II.

1. Mark I: a general-purpose, electromechanical programmable computer that used a mix of relays, magnets, and gears to process and store data. devised by Howard H. Aiken, and built at IBM in 1944. used by the U.S. Navy in WWII.

History of Computers

2. ENIAC (Electronic Numerical Integrator and Calculator): Completed in 1946 by John Mauchly and J. Presper Eckert at the University of Pennsylvania. First fully electronic general-purpose programmable computer in WWII. 1000 times faster than the MARK1. Contained 18,00-19,000 vacuum tubes, Nearly filled a building (100 feet long,10 feet high and weighed 30 tons). Programmed

externally.

History of Computers

3. Von Neumann: called the “Father of the Modern Computer”, proposed Von Neumann architecture (known as the stored-program computer model) in 1946. consisted of central arithmetic part, a central control part, a memory to store both data and instructions, external storage, and input and output mechanisms. Programmed

internally.

History of Computers The Modern Era: 1950 to the Present

1. The First Generation (1950-1959): used vacuum tubes to store data and

programs, large size (i.e. multiple rooms), and a lot of

heat.

2. The Second Generation (1959-1965): used the transistors, smaller size, and cheaper. High-level programming languages were born.

History of Computers

3. The Third Generation (1965-1975): used integrated circuits (known as microchip) rather than individual electronic components, further reduction in size and cost of computers.

4. The Forth Generation (1975-1985): appearance of microcomputer, computer networks, electronic mail, and graphical user interfaces.

History of Computers

5. The Fifth Generation (1985-present): handheld devices and wireless data communications appeared. Powerful processors and massive storage devices.

Types of Computers Computers can be divided into:

1. Super Computer: large size, huge capacity, high-speed processing, and linked with hundreds of end units. Very expensive ! e.g. can be found in Saudi Aramco.

2. Mainframe: used by large organisations such as banks to control the entire

business operation. Linked with many end units.

Types of Computers

3. Minicomputer: Smaller than mainframe, has become obsolete as having capacity equal to personal computer.

4. Personal Computer (PC) / Micro-computer:

Most people’s computer. Cheap and easy to use. Deals with one person only. e.g. Desktop, laptop, and pocket.

Types of Computers

5. Workstation: deals only with one person, but stronger in the process capability and the storage capacity of the memory. Huge capability in dealing with the drawing.

6. Network Computer: minimal memory, disk storage and processor power, designed to connect to a network, especially the  Internet. Less expensive than PCs.

Lecture 1 - Conclusion What is a COMPUTER? The history of Computers Types of Computers

Lecture 2 – Next Week! The main parts of the Personal Computer Computer Hardware Memory Measurement