ICTD 111 Introduction to ICT Systems Appiah Kubi Halifax Department of Mathematics Education University of Education, Winneba Winneba
System A system is set of independent parts that together accomplish specific objective.
computing system A computing system is the combination of hardware, software, data, procedures and you – all working together to get the most of using the computer.
computing system Con’t The computer accepts data: Accepting data, here, means that anything that you send into the computer be it characters or symbols on which operations are performed.
computing system Con’t The computer processes data means changing the data into meaningful information based on the instructions given.
computing system Con’t Procedures: Without proper procedures, you will be at loss about how to use the computer correctly. Processing data into information requires careful planning and appropriate instructions. If accurate data is not input, the information delivered as output is useless. This phenomenon is called: Garbage – in, Garbage – out (GIGO).
computing system Con’t You are the controlling force behind the computing system. By knowing the power and limitations of the computing, you are able to select the proper application to solve problems, produce information and become more efficient.
computing system Con’t NB: By far the most important component of the computing system is you using the computer.
computer system A collection of machines and programmes for providing computing services is known as a computer system.
computer system Con’t The computer system can be divided into 2 main categories namely: • Hardware. • Software. * However, there is the 3rd one known as the user.
The hardware It is the electronic and mechanical parts that you can see physically and touch.
The hardware Con’t In general, computer hardware falls into four categories: • Input unit/Input Hardware/Input Device • Output unit/Output Hardware/Output Device • Storage Unit/Storage Hardware/Storage Device • Processing Unit/Processing Hardware/Processing Device
Input Device Input devices are the devices that enable people to put or enter data into the computer for processing. The most common input device with microcomputers is: the keyboard. Others are mouse, voice recognition, light pen, scanner, floppy diskette, touch screen, digital camera, joystick, track ball, flash disk (aka pen drive).
Input Device Con’t NB: The Standard input devices are: the Keyboard and the Mouse.
Output Device Any device that can help us to produce output from the computer is an output device. Thus devices that translate information processed by the computer into a form that humans can understand are output devices. Examples include: (i)the monitor which is also known as the screen or visual display unit (VDU), (ii) Printers, (iii) Plotters, (iv) Voice output devices like speaker etc.
Output Device Con’t The output devices can also be divided into two namely: the soft copy device and the hard copy device. The soft copy output devices produce output that cannot be touched. The hard copy output devices produce output that can be touched like paper.
Output Device Con’t VDU Soft Copy Device Voice Output Devices Output Device Printers Hard Copy Device Plotters
Printer A printer is an output unit that converts computer data into printed characters or graphics on paper. Printers can be categorized under 2 main headings: (i) Impact Printers and (ii) Non-Impact Printers.
Impact Printers They are printers that make physical contact with the material on which they produce the output.
Non-Impact Printers They are printers that do not make physical contact with the material on which they produce the output.
Types of Printers Dot-Matrix Printers: Dot matrix is an inexpensive impact printer, which has lines of pins programmed to strike an inked ribbon against paper. It allows you to produce carbon copies. This process is noisy and slow.
Types of Printers Con’t Laser Printers: They are non-impact printers. Laser printers use toner to produce print outs. They produce much better image quality than dot-matrix printers.
Types of Printers Con’t Ink-Jet or Desk-Jet Printers: Ink-Jet printers are non-impact printers that spray one or more colors of small droplets of ink from an ink cartridge at high speed onto paper. The image is of high quality, like that of laser printers; however, ink-jet printers are slower than laser printers.
Note A hardware that is used for both providing information to the computer and receiving information from it is an input and output device. A floppy-disk drive is an example of input and output devices.
Storage Devices They are devices for recording computer data in temporary or permanent form. A computer have primary (or main memory) and secondary (or auxiliary) storage devices. The primary storage devices are the: Random Access Memory (RAM) – Impermanent and the Read Only Memory (ROM) – Permanent.
RAM Is the actual place where data and instructions are held temporary while the computer is working (i.e. computer’s work space).
RAM Con’t RAM is like a blackboard that can be erased and reuse again and again. The main drawback of RAM is that it is volatile (unstable). If once the power is turned off, all the contents (i.e. the data and programs) of RAM are lost unless battery power known as Uninterrupted/Uninterruptible Power Supply (UPS) is supplied to the RAM.
ROM Is the part of the main memory that contains system programmes in permanent form. It cannot be erased even if power is off.
ROM Con’t The computer cannot change the information stored in ROM. The information stored in ROM was manufactured and can only be read (retrieved) by the computer.
Note • A digit in binary (i.e. 0 or 1) is called a bit (Binary Digit) • A group of 8 bits is called a byte • Each byte represents a character (e.g. a, ?, . etc) • The size of a disk and memory is expressed in bytes (i.e. how much data can e.g. a floppy disk holds)
Processing Device The processing device is the device that does all the processing or computation of the raw data into useful information.
Software Software or Programs are the step – by – step instructions that tell the computer how to perform a task.
Software Con’t In computing, there are 2 major types of software: System Software or Operating System and Application Software
System software System software controls the physical components of the computer. It enables the application software to interact with the computer hardware.
System software Con’t It is also the Master control program in computer. That is the essential program in a computer that maintains disk files, runs applications, and handles devices such as the mouse and printer.
System software Con’t Examples of system software include: MS-DOS (Microsoft Disk Operating System), Windows, UNIX, LINUX, etc.
MS-DOS It is an operating system developed by Bill Gates for personal computers. It is a single-user OS. It is character user interface. The MS-DOS prompt is:
Windows (Microsoft Windows) Itis a multitasking graphical user interface environment that runs on MS-DOS based computers.
UNIX and LINUX • UNIX: It is also multi-user. It was developed in 1969 by Ken Thompson and Dennis. • LINUX: The first version of LINUX was written by LinusTorvalds, a second-year student of computer Science at the University of Helsinki in Finland in 1991. The basic LINUX OS is free.
Application Software Application software are software that people use to perform a general or specific task such as word processing software used to create, edit, save and print documents. Application software may either be customized or packaged.
Customized software Customized software is software designed for a particular customer. This is the kind of software that you would hire a professional computer programmer (a software creator) to develop for you.
Packaged software Packaged software is the kind of program developed for sale to the general public. Some types of packaged software include:
Packaged software Con’t Word processing: Word processing software allows a person to use a computer to create, edit, save and print documents. Examples of word processing software are WordPerfect, Microsoft Word, Ami Pro, Mac Write etc.
Packaged software Con’t Database Manager: A database manager is a program used to manage multiple data file. Examples are Dbase, Microsoft Access, Paradox, FoxPro etc
Packaged software Con’t Spreadsheet: Spreadsheet software allows a person to use rows, columns and formulae to display, analyze and summarize data, mostly numerical data. Examples are Lotus 1-2-3, Microsoft Excel, Javelin, Multiplan, Context MBA, SPSS (Statistical Package for the Social Sciences) etc.
Packaged software Con’t NB: Whiles word processing is largely used in text processing, spreadsheets are used for numeric data processing. Spreadsheet is a program that takes text and numbers but it is normally used for manipulation of numeric data.
How Computers Function Input Process Output Data Information