1. Overview of Introduction to Computers Prepared By : ASM ASHIF ASA University

3. Meanings of Computer Computer is a device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information. According to Collins English Dictionary, Computer is “A device, usually electronic, that processes data according to a set of instructions”. The actions carried by the computer are either arithmetic or logical in nature.

5. Types of Computers Personal computer: A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data. These are cost effective machines which are used for general purpose computations. Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor. Minicomputer: A multi-user computer capable of supporting from 10 to hundreds of users simultaneously. It is scaled down version of main frame machines designed to meet the computing needs of small and medium enterprise (SME). HP, IBM, SUN and Dell are some of the major vendors of mini computers.

6. Types of Computers Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously. They are usually installed in very large organizations such as banks, meteorological office, defense establishments etc. These machines have proprietary hardware and software. The cost of acquisition and maintenance of these machines are high. IBM is the most popular maker of mainframe machines and some of the models are 3090, ES/9000, and S/390 Supercomputer: An extremely fast computer that can perform hundreds of millions of instructions per second. It works on massively parallel architectures interconnecting more than one processor, has large quantity of main memory and secondary storage devices. It supports multiple users, use proprietary hardware and software, need special environment for working and are very expensive in both procuring and maintaining. Supercomputers are usually used for complicated computations such as weather forecasting and other scientific research requiring massive calculations.

13. A Typical Computer System

15. A Computer System Architecture Input Device: Punch card reader, Keyboard, Mouse, Scanner, Voice. Computer: CPU, Internal Memory Output Device: Monitor, Printer, Plotter, Modem, Disk Drive External Storage: Floppy disk,Hard disk, Optical disk, Tape drive

16. Basic Computer Organization ALU Control Unit Input Devices Output Devices Memory Central Processing unit CPU 3 8 9 5 2 1 4 6 7 11 10 12 T0 outside world From outside world

18. Hardware

34. Thank You