MIS 101 Ch 3

© 2001 Business & Information Systems 2/e 1

Chapter 3

Information System Fundamentals


Hardware for Information Systems



Computer and Communications Hardware Computer hardware: physical equipment that

makes up a computer is called hardware device. Input devices E.g include a keyboard, mouse,

scanner, digital pen, and digital tablet Output devices E.g include a screen, monitor,

printer, and fax. Primary storage e.g RAM Secondary storage E.g include hard disks,

floppy disks, ZIP disks, CDROMs, and DVDs. Central Processing Unit (CPU)

Computer and Communications Hardware Second component of hardware is

Communications hardware Network devices Network is a configuration of

computers connected electronically so that they communicate each other.



The Need for Computer Hardware

Speed: Ability to process data and produce information rapidly

business benefit from rapid processing by providing better service at reduced cost e.g. ATM is faster than human teller.

Accuracy: Assurance that processing result are correct

Business cost is greater and information is less reliable.

POS is more accurate than human clerk

The Need for Communications Hardware

Capacity: Ability to handle large amount of data

sales analysis systems can examine thousand of data.

Allow the firm to compete effectively with other business

Business can gain competitive advantage Continuously monitor the hardware

requirement for maintaining competitive advantage.



The Need for Communications Hardware

Remote access: access to information and processing at remote locations.

Information sharing: sharing of information related to business operation and management

Resource sharing: sharing of expensive and scarce computer resources

E.g. printers, file servers Interorganizational communication:

communication between computers in different business e.g. EDI,EFT


Types of Computer Systems

Variation of computer depends on capacity, speed and cost

Three main hardware configuration used for IS. Personal Computers(micro computer) Most widely designed microcomputer follow the design

of IBM IBM, Apple ii, Macintosh or Mac

Desktop Laptop Handheld (3com,Hewlett-Packard (HP) Personal Digital Assistant (PDA) Workstations(extra capabilities graphic diagram &

pictures) sun Microsystems.


Types of Computer Systems (cont’d.) Multiple-user computer systems( single computer used by

many people at one time) Minicomputer or mid range computer(used just a few

people at a time, small to medium size organization, used for checkout in the supermarket)

Typically between $5,000 and $200,000 e.g IBM &HP Mainframe computer(hundred to thousand people,

medium to large size organization. used for ATM in bank)

Typically between $100,000 and $10,000,000. Amdahl,Unisys

Super computer (5million to 20 million) Both are multi-user environments e.g Cray research


Types of Computer Systems (cont’d.) Networked computer systems

Many computers connected to a network used by many people at one time. micro,mini,mainframe,Super computer may be used. trend to use micro computer. Business replace their mini or mainframe to networked computer

Used for workgroup ,organizational systems,interorganizational systems

Servers – provide services to other computers on the network. used to store data& print out output from other computer also used to store information for internet users

Clients – a user’s workstation connected to the network. Client-server computing – servers store data for all client

and clients allow any user to retrieve the data.This approach is called client/server computing.


Types of Software A program is a set of instructions that tells the computer what to

do. Each instruction is followed step by step whether it is right or

wrong. The instruction is executed in sequence by CPU. sequence can be

changed by including special instruction. Eg. Decision and Loop. Application software – designed for specific computer applications

for a business or organization. Helps the business or organization function .Types individual ,workgroup, organizational & interorganizatiol application software.

System software – designed to make computers usable, always control in computer. Also known as an operating system. Helps the computer function.

Communications software – designed to permit computers to “talk” to each other.

PC and Network Operating Systems

Microsoft Windows is the most popular Installed more than other OS combined Installed on about 95% of computers Apple and Linux represent the other 5% Windows is gradually loosing its market share to other OS,

especially to Apple PC Operating Systems: DOS, Windows NT, Windows 9x, Windows

2000, Windows 7,Windows XP, UNIX, Linux Macintosh operating systems,os X Networking Operating Systems: NT Server, Windows 2000 Server,

Windows 2003 Server, Windows server 2008, UNIX for servers, Linux for servers

Embedded Operating Systems: Windows XP embedded, Windows CE, Windows mobile, Windows Phone 7, Palm OS, Pocket PC, Symbian, iOS, Android, Os© 2001 Business & Information Systems 2/e 12


Concept of Kernel or Supervisor

An operating system is a group of programs that manages the operation of the computer

Most operating system programs are stored in secondary storage.

One operating system program is stored in a section of primary storage. It goes by various names – kernel – but generally called the “supervisor”.

The part of primary storage not used by supervisor is used by other program

Supervisor pass the control of computer to the program &take control when program execution is finished

The supervisor controls all activity in primary storage.


Supervisor Loading Process Starting the computer is called booting which

transfers the “supervisor” from secondary storage to primary storage.

A special program for loading the supervisor into the primary storage is stored non volatile ROM

When the switched on, a circuit is activated that cause the program in ROM to execute.This program loads the supervisor into primary storage&transfer control or the computer to it.


Operating System Concepts

Three functions of an operating system Process management: Schedule program

for excution,start the excution of program,monitor the execution of program.

Resource management: primary storage, secondary storage and input output used by the systems and stored area.

Data management: movement of data from primary storage to appropriate place.

Using an Operating System Connecting to a network or other multi-user environment is

called logging in. Detaching from a network is called logging out. Operating system and other software use buttons,

icons,menus and other features that are said GUI User interface is the visual link between the user and the

software. Small pictures on the screen are icons. Graphical User Interface (GUI) uses

Buttons Icons Menus Dialog boxes



Capabilities of Operating Systems Multitasking is appearing to execute more than one program

at a time, though the CPU can execute instructions from only one program at a time.

Multi-user or Multiple-user programs permit more than one person to use the program, and data, at a time.

One technique that is used with multiple-user operating systems is time sharing. With this technique, the users are each allocated a small amount of time by the operating systems

Virtual memory is supplemental primary storage (RAM) or “real” memory where the programs are too big for primary storage. It is created on a secondary storage device, usually the hard drive, and is generally temporary in nature.

Need for software for Information Systems Information system function: performance of

input, processing, storage and output function Application software tells hardware how to perform

specific information Easy to use: provision that makes systems easy to

use. Creating platform: On which application software

run Choice of platform and specific hardware and

systems software affect the form of application software.



Sources of Software Two main sources of software

Packaged software – available commercially for personal, multiple-user and networked systems. personal and workgroup systems use it

Custom software – created to address very specific requirements of the users.


Programming Languages Two broad groups

Traditional programming languages Sequences of instructions First, second and some third generation languages Data processed by program is separate from

program perhaps stored in file or server. Object-oriented languages

Objects are created rather than sequences of instructions

Some third generation, and fourth and fifth generation languages

Instruction for processing for data and data are not separate but combined to form an object.


Traditional Programming Languages FORTRAN (traditional language)

Formula Translation. Developed at IBM in the mid-1950s. Designed for scientific and mathematical applications by scientists and

engineers. COBOL (traditional language)

Common Business Oriented Language. Developed in 1959. Designed to be common to many different computers. Typically used for business applications.

BASIC (traditional language) Beginner’s All-purpose Symbolic Instruction Code. Developed at Dartmouth College in mid 1960s. Developed as a simple language for students to write programs with

which they could interact through terminals.


Traditional Programming Languages (cont’d.) C (traditional language)

Developed by Bell Laboratories in the early 1970s. Provides control and efficiency of assembly language while having third

generation language features. Often used for system programs. UNIX is written in C.

Smalltalk (object oriented language) First object-oriented language. Developed by Xerox in mid-1970s. Still in use on some computers

C++ (object oriented language) It is C language with additional features. Widely used for developing system and application software. Graphical user interfaces can be developed easily with visual

programming tools


Special Programming Languages HTML

HyperText Markup Language. Used on the Internet and the World Wide Web (WWW). Web page developer puts brief codes called tags in the page to

indicate how the page should be formatted. XML

Extensible Markup Language. A language for defining other languages.

JAVA (object oriented language) An object-oriented language similar to C++ that allows a web

page developer to create programs for applications, called applets that can be used through a browser.

Objective of JAVA developers is that it be machine, platform and operating system independent.


Stored Data for Information Systems



Data Organization Elements of data storage

Characters – letters, numerals, special symbols, a blank space.

Fields – a group of related characters. Records – a group of fields about a

single entity. Data file, or file – a group of records

about a single purpose. Database – a group of related files.

Data Organization



Data Organization (cont’d.) While data can be organized in a

database, there are other types of data. Multimedia

Audio Video Images


Need for Stored Data Three main reasons businesses need

stored data Data is available: Easy of locating and

retrieving data for processing Data is modifiable: Ease of updating

datafor changes in the business. Stored data reflect the state of business.

Data is controllable: Assurance data is accurate and secure. Data is important asset of organization.Acronym GIGO


Personnel for Information Systems



Users and Operating Personnel Users

Supply data input Receive outputs

Operating personnel Perform technical functions such as

Input data for systems Manage networks Run software Pass output to users Pass output for the user.

Need for perosnal for Information systems Information use: Use of

information for operaition and management of the business

System operation: operation of hardware and software of systems and correction of problem that arise.



Types of Procedures Two main types

First tells people how to use and operate the system under normal circumstances. e.g what option to select to begin running software.

Second tells people what to do if the system does not function normally. e.g backup recovery procedure

Documentation is written instructions on the use and operation of the system.

When we say personnel is a component of computer we mean personnel who are trained in the use of the procedure

Need for procedure for Information SystemsPeople does not know instinctively how to

use or operate complex systems. e.g a person using automobile need procedures for driving the car and for repairing the car

Use of system: Knowledge of how to start the systems, interact with the systems and stop the systems

Correction of system: knowledge of problem correction process.


Documents

MIS 101 Ch 3