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UNIVERSITY OF KABIANGA
CCM 201:COMPUTER SKILLS
LECTURE NOTES
INTRODUCTION TO COMPUTERS
Definition of Terms Computer – refers to an electronic device capable of accepting data as input and processes it under the influence of a set of instructions referred to as software/programs to produce information as output.
Data - refers the raw facts fed into the computer for processing. Data does not have any meaning to the user e.g. raw students marks fed into the computers.
Information – refers to the already processed data summarized in the form that the user wants. Information makes sense to the user e.g. computed average marks.
A Computer as a System – combination of different components or elements of the computer which each performs its own tasks but work together to process data into information.
3. COMPUTER HARDWARE AND SOFTWARE
The computer system is made up of the following components;
- Hardware
- Software
- Liveware
HARDWARE
This refers to the physical tangible components of the computer. Hardware can be classified into;-
I Input devices Refers to the devices used to feed data into the computer. E.g. Keyboard, mouse, Joystick, light pen, digital cameras etc.
CameraJoystickMouseKeyboard
II Output devices. Refers to the devices used to give feedback or information from the computer e.g. monitor, projector, printer, speakers, etc.
i. Processing hardware Responsible for the processing of data into information. This is normally the CPU (Central Processing Unit). It is the “Brain” of the computer. The processing speed of a computer depends on the processor speed (clock speed) measured in number of instructions processed per time (Hertz) e.g. 1.65 GH
CRT MonitorTFT/LCD Monitor
VP6320 DLP
Projector XGA 20000 Lumens
HP Laser Jet 1160 Printer
The motherboar d/system board and the CPU
Flow of data/ instructions in the CPU
over a network Utility– used to manage computer files, diagnose and repair computer problems e.g. antivirus, compilers, diagnostic tools etc Operating systems – provides the interface between the user, the hardware and the application software
b). Application software – type of software that solve specific problems or perform specific tasks. It is divided into; Off – the – shelf application software – programs developed by software engineers and made available in the market for sale. Normally sold in bundles called program suites e.g. the Microsoft Office programs suite. In – house –developed packages – also referred to as tailor – made – application software. Designed or tailored to solve problems specific to an organisation.
Liveware (Orgware/people) Refers the computer professionals e.g. network administrators, programmers and computer end-users
4. OPERATING SYSTEMS
An operating system refers to the computer software that provides the Inter face between the hardware, the user and the application software.
The functions of the operating system are; a. Job scheduling – includes preparing, scheduling and monitoring jobs for continuous processing by the computer. b. Resource control – includes controlling the use of computer resources by other system software and application programs being executed. c. Input/output handling – it controls the allocation of i/o devices and resolves Conflicts that may occur if more than one application program or users request the same device at the same time. d. Memory management – it determines how much memory is allocated to user programs. e. Error handling – it deals with errors which are produced during program execution and keep the computer running when errors do occur.
Example of operating system: Ms DOS, PC DOS, UNIX, Linux, XP, Windows etc.
Booting a Computer
Booting refers to the process on starting up a computer. There are two ways of booting up a computer; a. Cold booting – done using the power button on the computer’s system unit. Normally done when the computer is initially off. b. Warm booting – this is done when the computer hangs (it temporarily stops to receive instructions). It is done by use of the reset/restart button on system unit or by a combination of the following keys from the keyboard; CTRL + ALT +DEL.
Starting up the Computer (Cold Booting)
- Check all the power connections from the mains through the back up to the system unit to ascertain proper connections
- Switch on power from the mains and then the back up
- Switch on power from the monitor and then the system unit
- (^) Wait as the computer performs POST (Power on Self Test) and as it loads the Operating System.
Shut Down Procedure
- When one is through with working with the computer, it is advisable to safely
Window Elements a. Title bar – shows the name of window opened
