Introduction to Information and Communications Technology (ICT) PDF

Introduction to Information and Communications Technology (ICT) Dr. AHMED HAMDY ABU-ELKASEM 1  Lecture_2 outlines 1. Classification of Computer. 2. The Computer System. 3. Computer Hardware 2 1. Classification of...

Introduction to Information and Communications Technology (ICT) Dr. AHMED HAMDY ABU-ELKASEM 1  Lecture_2 outlines 1. Classification of Computer. 2. The Computer System. 3. Computer Hardware 2 1. Classification of Computer 1.1 Embedded Computers An Embedded computer is a tiny computer embedded into a product designed to perform specific tasks or functions for that product. For example, computers are often embedded into household appliances to help those appliances and objects perform their designated tasks. 3 1. Classification of Computer 1.2. Mobile Devices A mobile device is a very small device that has built-in computing or Internet capability can typically be used to make telephone calls, send text messages, view Web pages, take digital photos, play games, download, and play music, watch TV shows, and access calendars and other personal productivity features. 4 1. Classification of Computer 1.3. Personal Computers (PCs) 1.3.1 Desktop Computers Desktop computers can use a tower case , a desktop , or an all-in-one case. Desktop computer systems usually conform to one of two standards or platforms: PC-compatible or Mac. PC run the Microsoft Windows operating system. Mac computers are made by Apple and use the Mac OS operating system. powerful desktop designed for users running powerful applications are sometimes referred to as workstations. 5 1. Classification of Computer 1.3. Personal Computers (PCs) 1.3.2. Portable Computers designed to be carried around easily very flexible designed to be powered by rechargeable batteries a) Notebook computers (laptop) are about the size of a paper. comparable to desktop computers in features and capabilities. 6 1. Classification of Computer 1.3. Personal Computers (PCs) 1.3.2. Portable Computers b) Tablet computers are typically about the size of a notebook computer and are designed to be used with a digital pen/stylus or touch input c) Hybrid notebook-tablet computers (convertible tablets) can function as either a notebook or a tablet computer. d) Netbooks are like notebook computers but are smaller and have more limited features, such as relying on cloud software. 7 1. Classification of Computer 1.4. Servers A Server )minicomputer( is a computer used to host programs and data for a small network larger, more powerful, and more expensive. Users connect to the server through a network, using their desktop computer. 8 1. Classification of Computer 1.5. Mainframe A mainframe computer is a powerful computer used by many large organizations— such as hospitals, universities, large businesses, banks, and government offices Larger, more expensive, and more powerful than servers. During regular business hours, a mainframe typically runs the programs needed to meet the different needs of its wide variety of users. At night, it commonly performs large processing tasks, such as payroll and billing. 9 1. Classification of Computer 1.6. Supercomputer Supercomputers—the most powerful and most expensive type of computer available. used for some applications require extraordinary speed, accuracy, and processing capabilities. for example, sending astronauts into space, controlling missile guidance systems and satellites, forecasting the weather, exploring for oil, breaking codes. supercomputers generally run one program at a time, as fast as possible. Example, the Titan supercomputer occupies 4,352 square feet of floor space and contains 299,008 CPUs. 10 2. The Computer System: a) Hardware The physical parts of a computer, can be internal or external. b) Software The term software refers to the programs or instructions used to tell the computer hardware what to do. c) Data are isolated values or raw facts, provided as input to the computer. d) Users are people who write computer programs or interact with the computer. 11 3. Computer Hardware: ✓ The Memory unit, which holds both data and instructions. ✓ The Arithmetic/logic unit, which can perform arithmetic and logic operations on data. ✓ The Input unit, which moves data from the outside world into the computer. ✓ The Output unit, which moves results from inside the computer to the outside world. ✓ The Control unit, which serves as the stage manager to ensure that all the other components act in concert. 12 3.1 Digital Data Representation All computers today are digital computers (binary computers). All data processed by a binary computer must be in binary form (0s and 1s). These 0s and 1s are commonly referred to as bits. large numbers of bits are needed to represent a written document, computer program, digital photo, music file, or virtually any other type of data. Eight bits grouped together are collectively referred to as a byte. a kilobyte (KB) = 1,024 bytes, a megabyte (MB) = 1,024 kilobytes (KB); a gigabyte (GB) = 1,024 megabytes (MB); a terabyte (TB) = 1,024 gigabytes (GB). 13 3.1.1 Coding Systems for Text-Based Text-based data is represented by binary coding systems namely, ASCII, EBCDIC, and Unicode. ASCII character sets and EBCDIC represent each character as a unique combination of 8 bits (1 byte), which allows 256 (28 = up to 256 characters). Unicode represent text-based data written in any ancient or modern language, including those with different alphabets. It is a longer code, consisting of 1 to 4 bytes (8 to 32 bits) per character, and can represent over one million characters. Unicode is updated regularly to add new characters and new languages not originally encoded. 14  3.1.1 Coding Systems for graphics, Audio and Video Most common methods for storing graphics data are in the form of a bitmap image—an image made up of a grid of small dots, called pixels that are colored appropriately to represent an image. The color to be displayed at each pixel is represented by some combination of 0s and 1s. Audio data—such as a song or the sound of someone speaking—must be in digital form to be stored on a storage medium or processed by a computer. To convert analog sound to digital sound, several thousand samples are taken every second. Video data—such as movies, films, video clips, and television shows—is displayed using a collection of frames; each frame contains a still image. When the frames are projected one after the other the illusion of movement is created. Before a computer can execute any program instruction it must convert the instruction into a binary code known as machine language. Example) 01011000011100000000000100000010). Early computers required programs to be written in machine language, but today’s computers allow programs to be written in a programming language, which is then translated by the computer into machine language to be understood by the computer. 15 3.1 INSIDE THE SYSTEM UNIT 16 3.1 INSIDE THE SYSTEM UNIT 3.2.1 The Motherboard The main circuit board inside the system unit containing computer chips and other electronic components. All devices used with a computer need to be connected via a wired or wireless connection to the motherboard. Typically, external connect to the motherboard by plugging into a port. 3.2.2 The Power Supply and Drive Bays The power supply inside a desktop computer connects to the motherboard to deliver electricity to the computer. Portable computers almost always contain a rechargeable battery pack. 17 3.1 INSIDE THE SYSTEM UNIT 3.2.3 Processors The primary processor is the central processing unit (CPU)—also called the microprocessor. Most personal computers and servers today use Intel or Advanced Micro Devices (AMD) CPUs. tablets and mobile phones often use processors manufactured by other companies (such as ARM). Another processor located inside the system unit is the graphics processing unit (GPU). processors are incorporated into a variety of products today, such as TVs, smart meters, cars, gaming consoles, exercise machines, electric toothbrushes, and ATM machines ……….. 18 3.1 INSIDE THE SYSTEM UNIT 3.2.3 Processors Processing Speed measurement of the processing speed of a CPU is the CPU clock speed, in megahertz (MHz) or gigahertz (GHz). today’s fastest CPUs designed for PCs have a clock speed of more than 4 GHz. benchmark tests measure how long each task takes in order to determine the overall relative performance of the component being tested. 19