Computer is an electronic device that manipulates data according to set of instructions and produce a meaningful result. • Computers are not very intelligent devices, but they handle instructions flawlessly and fast. • They must follow explicit directions from both user and computer programmer. • Computers are really nothing more than a very powerful calculator with some great accessories. • Applications like word processing and games are just a very complex math problem. A computer is an electronic device that stores, retrieves, and processes data, and can be programmed with instructions. A computer is composed of hardware and software, and can exist in a variety of sizes and configurations.
Capabilities of a Computer
1. The computer has the ability to perform arithmetic operations like addition, subtraction, multiplication, etc. 2. The computer also performed logical operations.
3. The computer has the ability to store and retrieve information because it has a storage device. 4. The computer has the ability to process information at a very high speed (1 millisecond) 5. The computer can direct itself in a predetermined manner without human intervention.
Limitations of Computer
1. The computer does not think for you.
2. The computer cannot correct inaccurate data
3. The computer is subject to breakdown.
Hardware and Software
The term hardware refers to the physical components of your computer such as the system unit, mouse, keyboard, monitor, etc.
The software is the instruction that makes the computer work. Software is held either on your computer hard disk, CD-ROM, DVD or on a diskette (floppy disk) and is loaded from the disk into the computers RAM (Random Access Memory), as and when required.
Two Types of Computer
1. Mini and Mainframe Computers
Very powerful, used by large organizations such as banks to control the entire business operation. Very expensive! Mainframes are computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics, and financial transaction processing. 2. Personal Computers
Cheap and easy to use. Often used as stand-alone computers or in a network. May be connected to large mainframe computers within big companies. Personal Computer is any general-purpose computer whose size, capabilities and original sales price make it useful for individuals, and which is intended to be operated directly by and end user, with no intervening computer operator.
1. Input Devices (“How to tell it what to do”)
An input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system (such as a computer).
A keyboard and mouse are the standard way to interact with the computer. Other devices include joysticks and game pads used primarily for games. 2. Output Devices (“How it shows you what it is doing”)
An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system to the outside world.
The monitor is how the computer sends information back to you. A printer is also an output device.
Used to ‘drive’ Microsoft Windows
The keyboard is still the commonest way of entering information into a computer. • Tracker Balls
An alternative to the traditional mouse and often used by graphic designers. • Scanners
A Scanner allows you to scan printed material and convert it into a file format that may be used within the PC. • Touch Pads
A device that lays to desktop and responds to pressure • Light Pens
Used to allow users to point to areas on a screen
Many games require a joystick for the proper...