Lecture 1.pdf

Lecture 1 By M.SAAD ALI For 3rd-Sem (PS+PPS) INTRODUCTION TO COMPUTING 1.1 What is Computer? Def1: An electronic machine that can store and process information. It is defined as stored program digital co...

Lecture 1 By M.SAAD ALI For 3rd-Sem (PS+PPS) INTRODUCTION TO COMPUTING 1.1 What is Computer? Def1: An electronic machine that can store and process information. It is defined as stored program digital computing system Def2: A Computer is an electronic device of wires, transistors, circuits, instructions, and data can transmit, store and manipulate information. Def3: A Computer is a machine that accepts data and processes that data (data may be numbers, letters or both or even sounds). Information is turned into electrical pulses so that it may be processed by sorting, collating and deleting mathematical manipulation and other forms of data processing Def4: A computer accepts information using an input device. The information is processed by a central processing unit or stored in a storage unit i.e. Hard Disk and then processed 1.2 Basic Computer Operations: To understand computer basic concept one must know about the 4 functions or Operations of the computer. 1.2.1 Input Operation: The computer receives information from users. A user enters information using input devices like keyboard, mouse or any otherdevices like webcam, punch card, magnetic tapes, joystick or magnetic disk etc. The Input unit accepts information using input devices then it converts the given data to readable form and this data moves to Central Processing Unit (CPU). 1.2.2 Storage Operation: The given information stored in a computer using the different storage devices i.e. central process unit and auxiliary memory. The auxiliary memory is also known as secondary or external storage have hard devices for example Floppy, Hard Disk, Compact Disk and Flash Drive. These different storage devices have both advantages and disadvantages. Auxiliary storage speeds up information and stores it long term and permanent. 1.2.3 Processing Operation: It is considered the basic computing operation. It executes the instructions, control storage data and input or output devices attached the computer 1.2.4 Output Operation: Last but not the least the output unit which represents results from the operations of central processing unit CPU. The result may be in hard or soft form i.e. visual display unit, printers, and headphones 1.3 History of Compute: The computer as we know it today had its beginning with a 19thcentury English mathematics professor named Charles Babbage. He designed the Analytical Engine and it was this design that the basic framework of the computers of today are based on. Generallyspeaking, computers can be classified into three generations. Each generation lasted for a certain period of time, and each gave us either a new and improved computer or an improvement to the existing computer.  1.3.1 First Generation 1937 – 1946: In 1937 the first electronic digital computer was built by Dr. John V. Atanasoff and Clifford Berry. It was called the Atanasoff-Berry Computer (ABC). In 1943 an electronic computer name the Colossus was built for the military. Other developments continued in 1946 the first general– purpose digital computer, the Electronic Numerical ntegrator and Computer (ENIAC) was built. It is said that this computer weighed 30 tons, and had 18,000 vacuum tubes which were used for processing. When this computer was turned on for the first time lights dim in sections of Philadelphia. Computers of this generation could only perform a single task, and they had no operating system. First Generation Computer 1.3.2 Second Generation 1947 – 1962: This generation of computers used transistors instead of vacuum tubes which were more reliable. In 1951 the first computer for commercial use was introduced to the public; the Universal Automatic Computer (UNIVAC 1). In 1953 the International Business Machine (IBM) 650 and 700 series computers made their mark in the computer world. During this generation of computers over 100 computer programming languages were developed, computers had memory and operating systems. Storage media such as tape and disk were in use also were printers for output. Second Generation Computer 1.3.3 Third Generation: 1963 - Present: The invention of integrated circuit brought us the third generation of computers. With these invention computers became smaller, more powerful more reliable and they are able to run many different programs at the same time. In1980 Microsoft Disk Operating System (MS-Dos) was born and in 1981 IBM introduced the personal computer (PC) for home and office use. Three years later Apple gave us the Macintosh computer with its icon-driven interface and the 90s gave us Windows operating system. As a result of the various improvements to the development of the computer, we have seen the computer being used in all areas of life. It is a very useful tool that will continue to experience new development as time passes.