Chapter 3 Hardware and software 1

Learning objectives After this lecture, you will be able to: categorise the type of computer system that a business uses; recognise the different components of a computer; explain the purpose of software applications in different categories; describe the features found in a variety of modern applications software packages; identify some of the advantages and disadvantages associated with a variety of common applications; describe some of the ways in which applications software supports the activities of a business organisation. 2

Management issues From a managerial perspective, this chapter addresses the following areas: Learning the characteristics of input, output and storage devices will allow managers to select the correct equipment for a given application. An increased understanding of computers will help managers to see how technology can be used to improve existing business processes and identify potential applications. All major organisations make use of common applications, such as word processing and spreadsheet software. An understanding of the factors involved with selecting these applications is required by all managers. An understanding of the range of software applications available will help managers to see potential applications relevant to a given organisation or industry. An understanding of recent developments in the software industry, such as the emergence of XML, will help managers to develop long-term plans for the organisation’s use of technology. 3

Hardware

Key concepts Computer system: Interrelated components including hardware and software that work together with the aim of converting data into information. Hardware: The physical components of a computer system: input devices, memory, central processing unit, output devices and storage devices. 5

Figure 3.1 Basic hardware components of a computer system 6

Hardware components Input device: Hardware used to enter data, information or instructions into a computer-based information system. Central processing unit (CPU): The processor found in a computer system that controls all of the computer’s main functions and enables users to execute programs or process data. Memory: A temporary means of storing data awaiting processing, instructions used to process data or control the computer system, and data or information that has been processed. Storage devices: A permanent means of storing data and programs until they are required. Output devices: Translate the results of processing – output – into a human readable form. 7

The client/server concept Client/server: The client/server architecture consists of client computers such as PCs sharing resources such as a database stored on a more powerful server computer. Give examples: In the office or university Within a company with multiple sites In the context of the Internet. 8

Figure 3.2 Input devices in context 9

Input devices Optical character recognition (OCR) Optical mark recognition (OMR) Bar code reader: Touch screen Voice recognition 10

Selecting input devices – key issues Volume Speed Accuracy Cost Data complexity Frequency of data entry. 11

Figure 3.4 Output devices in context 12

Output devices Visual display unit (VDU) Video projector Plotter Printer 13

Selecting output devices – key issues Appropriateness Permanence Response time Speed Cost Data complexity Frequency of data entry. 14

Figure 3.5 Storage devices in context 15

Storage devices Primary storage: Data and instructions are loaded into memory such as random access memory. Such storage is temporary. Random access memory (RAM) Read-only memory (ROM) Secondary storage: Hard disks and USB sticks are examples of secondary storage and the storage is permanent. CD-ROM Digital versatile disc (DVD) 16

Measuring storage capacity Bit: A single binary digit representing a (0) zero or a 1. Byte: Made up of eight bits and represents the amount of space required to hold a single character. Kilobyte (kb): Approximately 1000 bytes, or the equivalent of 1000 characters. Megabyte (Mb): Approximately 1000 kb, or the equivalent of one million characters. Gigabyte (Gb): Approximately 1000 Mb, or the equivalent of one billion characters. Terabyte (TB): Approximately 1000 Gb. 17

Figure 3.6 The processor in context 18

Processors Processor: Uses instructions from software to control the different components of a computer. Clock speed: Measured in MHz (megahertz, or millions of pulses per second). Bus width: Describes how many pieces of data can be transmitted or received at one time by the bus connecting the processor to other components of the PC. 19

Virtual computing Virtual computing involves simulating a complete computer system in software. The virtual machine (VM) behaves exactly the same as a physical computer system and can be used in the same way. 20

Software

software Software: A series of detailed instructions that control the operation of a computer system. Software exists as programs that are developed by computer programmers. Figure 3.8 Categories of computer software

Categories of software Systems software: This form of software manages and controls the operation of the computer system as it performs tasks on behalf of the user. Operating system (OS): Graphical user interface (GUI) Applications software: A set of programs that enable users to perform specific information-processing activities that may be general-purpose or application-specific. word processor (Microsoft word ) spreadsheet database 23

Internet concepts Internet: A global network system made up of many smaller systems. World Wide Web (WWW): Interlinked documents on the Internet made up of pages containing text, graphics and other elements. Hypertext Markup Language (HTML): WWW pages are mainly created by producing documents containing HTML commands that are special tags (or codes) to control how the WWW page will appear when displayed in a web browser. Web browser program: Enables users to navigate through the information available and display any pages of interest. Hypertext: Hypertext is a document containing highlighted words or phrases that represent links to other documents activated by clicking the mouse. 24

Web 2.0 The term Web 2.0 describes a new generation of applications and services that allows Internet users to communicate, share information and do business in new ways. 25