Introduction to Information Technology (UR1) Lecture 1 PDF

Introduction to Information Technology (UR1) Lecture (1) Assoc. Prof. Mahmoud M. Saafan Dr. Eman M. El-Gendy  What is a Computer? A data processor because it can store, process, and retrieve data whenever desired. Data can be numeric...

Introduction to Information Technology (UR1) Lecture (1) Assoc. Prof. Mahmoud M. Saafan Dr. Eman M. El-Gendy  What is a Computer? A data processor because it can store, process, and retrieve data whenever desired. Data can be numerical, alphabetic, alphanumeric, text, image, voice or video. Information is data arranged in an order and form that is useful to people receiving it.  What is a Computer? An electronic device that can: 1. accept data. 2. store data. 3. process data. 4. retrieve the stored data. 5. print the result. Characteristics of computers Speed. Accuracy. Diligence. Versatility. Power of Remembering. No Intelligence. No Feeling.  Computer Generations “Generation” in computer talk provides a framework for the growth of computer industry based on key technologies developed. There are five Generations of Computers: First Generation Computers (1942-1955). Second Generation Computers (1955-1964). Third Generation Computers (1964-1975). Fourth Generation Computers (1975-1989). Fifth Generation Computers (1989-Present).  First Generation Computers (1942-1955) Vacuum tube using filaments. Large in size. Writing programs on them was difficult. Stored program concept: the principle of storing program instructions along with data in memory of computer so that they could automatically execute a program without human intervention. Machine and assembly languages.  First Generation Computers (1942-1955) Limitations: The operating speed was quite slow. Power consumption was very high. It required large space for installation. The programming capability was quite low.  First Generation Computers (1942-1955) ENIAC: Electronic Numerical Integrator and Calculator. The first electronic computer built in 1946. 30×50 feet long, weighed 30 tons. Required 150,000 watts of electricity. First Generation Computers (1942-1955)  First Generation Computers (1942-1955) EDVAC: Electronic Discrete Variable Automatic Computer. Developed in 1950. Introduced the concept of storing data and instructions inside the computer. Allowed much faster operation since the computer had rapid access to both data and instructions.  Second Generation Computers (1955-1964) Transistors. Very low manufacturing cost. Reduced size. CPU, memory, programming language and input and output units.  Second Generation Computers (1955-1964) IBM 1620: Smaller as compared to First Generation computers. Used for scientific purpose. IBM 1401: Small to medium size. Used for business applications. CDC 3600: Large size. Used for scientific purposes.  Third Generation Computers (1964-1975) Integrated Circuits (ICs) Chips: many transistors built on a single thin slice of silicon. Small in size. Low cost. Large memory. High processing speed. Higher level language such as BASIC. IBM-360, ICL-1900, IBM-370, and VAX-750.  Fourth Generation Computers (1975-1989) Microprocessors: large scale Integrated Circuits (LSIC) built on a single silicon chip. CPU on single chip. Very large scale Integrated Circuits (VLSIC) later replaced LSICs. More reduced size.  Fifth Generation Computers (1989-Present) Ultra Large Scale Integrated Circuits (ULSIC). Extremely high speed. Parallel processing. Artificial intelligence. Classification of Computers Classical Classification  Classification of Computers Modern Classification Notebook computers (Laptops). Personal computers (PCs). Workstations. Mainframe systems. Supercomputers. Clients and servers. Handheld computers.  Notebook computers (Laptops) Portable computers. Chargeable batteries. Good processing capability. Maximum power saving. MS-DOS, MS WINDOWS, Mac OS, or Linux operating system. Suitable for all applications. Notebook computers (Laptops)  Personal computers (PCs) Non-portable. Fits on a normal size office table. One user at a time. Several chips assembled on motherboard. MS-DOS, MS WINDOWS, Mac OS, or Linux operating system. Suitable for all applications. Personal computers (PCs)  Workstations Powerful desktop computer. Greater processing power. Larger storage. Better graphics display. One user at a time. Suitable for engineers, architects, and other professionals. Workstations  Mainframe systems Massive processing capability. Massive data storage capability. Needs a large room with closely monitored humidity and temperature. Suitable for organizations that need on-line processing of large number of transactions. Mainframe systems  Supercomputers The most powerful and expensive computers. Multiprocessing and parallel processing technologies. Huge cost. Suitable for processing complex scientific applications requiring enormous processing power. Used for weather forecasting, biomedical research, aircraft design and other areas of science and technology. Supercomputers  Clients and servers Multiple users can share several resources/services for cost-effective usage. Shared resources/services managed centrally. The computer on which the server process runs is called a server computer. Computers on which client processes run are called client computers. Clients and servers  Handheld computers Small computing device hold in hand. Palmtop. Computing power anytime or anywhere. Tablet PC: Laptop with light weight, screen flip, voice recognition, and specially designed pen for handwriting.  Handheld computers PDA/Pocket PC: Personal Digital Assistant (PDA). Personal Information Manager (PIM). Decent size LCD touch screen with a pen for handwriting recognition.  Handheld computers Smartphone: Fully functional mobile phone with computing power. Cell phone with PDA-like capability. Smaller than PDAs.