1. COMPUTERS

2. What is a computer? It is a set of electronic devices that can systematically and sequentially follow a set of instructions called a program to perform high-speed arithmetic and logical operations on data. A computer basically processes data to give information. The areas of application of computers span almost every field of endeavour namely manufacturing, commerce, business, librarianship, engineering, archives administration, records management, medicine, entertainment, military manoeuvring, finance, law and crime, banking 3. Advantages of Computers Accuracy Speed (faster) Undertake complex processing Stores large volume of data/information Cheaper in terms of processing data compared with manual processing 4. Disadvantages of Computers Expensive (Cost of buying and maintenance) It creates unemployment It is human dependent It is also highly dependent on external power Associated with harmful effects e.g. radiation, stress, bad posture, isolation, etc 5. Functional Structure of Data Processing System (Computer) Data: is raw or unrelated facts or figures without meaning or raw facts about an event or activity or entities. Information: is processed data with meaning. Program: a set of instruction that the computer follows in order to perform its functions or operations.Input (Data)Processing (Program)Output (Information) 6. Six Basic Functions of a Computer 1.Input The process of sending data into the computer using input devices like mouse, keyboard, joystick, bar code reader, monitor, etc. 2. Processing The changes or manipulation that data undergoes to become information. It simply the conversion of raw input into a form that is more meaningful to humans. This is achieved by using a computer program; and it is done in the systems unit (processor, memory, storage devices, ALU). 3. Output Is the result that comes out after processing of data- information; using devices like printer, speaker, plotters, monitor, etc. An output could be in two forms: softcopy output (onscreen output) or hardcopy output (printed output). 7. Six Basic Functions of a Computer 4. Filing Computers store data or information using filenames and extension names. E.g. micky.doc, micky.xls, micky.html, etc 5. Sorting Computers are capable of arranging files, data, and records in a predefined order. Computers sorts data/information during storage either by name, date, size, etc 6. Control Putting checks on processes to meet the criteria for evaluating operations. 8. TYPES OF COMPUTERS Super computersThe largest, most powerful and most expensive computers in the world, with high processing and storage capacity. They are used by large organizations normally government sponsored organizations, for highly complex activities such weather forecasting, space exploration, etc.The IBM's Sequoia and Bitcoin Network are amount the fastest in the world 9. TYPES OF COMPUTERS Super computersThe largest, most powerful and most expensive computers in the world, with high processing and storage capacity. They are used by large organizations normally government sponsored organizations, for highly complex activities such weather forecasting, space exploration, etc.The IBM's Sequoia and Bitcoin Network are amount the fastest in the world 10. TYPES OF COMPUTERS Mainframe computers Large computers, capable of great processing speeds and data storage. Use by large organizations who handle large volumes of data banks, universities, Insurance companies etc.It normally supports database accessibility by mini/micro computers. 11. TYPES OF COMPUTERS Mini or Midrange computers A midrange computer is a medium-sized computer system or server that covers a very broad array and resides in capability between high-end PC servers and mainframes. They usually fall in between mainframe computers and microcomputers. 12. TYPES OF COMPUTERS Micro-computers The smallest of the types of computers. Consist of microprocessor chip. There are two types, portable microcomputers (e.g. laptops, notebooks, palmtops, tablets, smart phones, etc.), and Desktop small enough to fit unto a desk but large enough to be carried about (e.g. PC). Suited for offices and homes. Comes with interfaces that permit the use of peripheralsscanner, printer, speakers etc. or sharing of these facilities