Chapter 1 : Introduction To computers
What is a computer?
- Defined as Electronic Data Processor (EDP) to emphasize that it processes data to produce
- Computer is machine that can perform for operations; input, output, processing, and storage.
These four operations in order were called Information Processing Cycle.
* Text - consist of standard alphabetic, numeric, and special characters
* Graphic - consist of pictures such as drawings, or photographs.
* Audio - involves any type of sound such as music and video
* Video - consist of motion pictures, and sound such as movie clips, animation and live video
* Data Processing - it is the process of converting data into information using some basic
* Computer System - it refers to both hardware and software.
* Computer Program - A computer program is a set of instructions written in one of the computer
Basic Computer Operations
* Input - the computer accepts data from the user.
* Processing - the computer converts data into information according to a program.
* Output - the computer displays the results on the screen or prints them on a printer.
* Storage - the results of processing can be stored for future use. ( hard disks,flash memory)
Components of a Computer System
* Computer hardware;
- The physical equipment used in computing
- Physical components of the computers of the computer system such as the keyboard, mouse,
display unit, memory, storage devices and processor.
Hardware is categorised into following;
- Input devices are any equipment that supplies data to the computer.
- Output devices are any equipment that is used to output information from the computer.
- Central Processing unit which includes the processor and the main memory (RAM)
- Secondary storage devices such as hard disks, ZIP drives, CD-ROM drives.
- Communication devices that connect the computer to other computers to a form a network.
* Computer Software;
- The set of instructions that controls the hardware
- Computer programs and can be classified into two basic categories System software and
System software includes;
- Operating System which provide at least the following functions; start the computer, manage
programs, manage memory, handle input and output.
- Utilities which are programs that keep the computer system running smoothly such as anti-virus,
disk defragmenter, disk cleanup.
- Language Translator which translates programs from high level languages such as C, C++ and
Java into the machine language.
Application Software includes;
- Prewritten software which is also called packaged software or off-the-shelf software.
- Custom Application Software which are created for business organization either by their
Information Services unit or developed specially for the organization by some software house.
Type of Computers
Computers for individuals;
Personal computer - allows for the creation computers small enough to fit on the top of a desk
Mobile devices - small computing devices such as wireless phones or pagers.
Workstations - provide powerful processing power and input/output capibilities.
Computer for organizations;
Mainframes - multi-user large scale computer system which is suitable for almost all large
Midrange computers - Medium sized multi-user computer system. fall between microcomputer
Super computers - Used in organizations that has extraordinary demands of processing power.
Chapter 2 : Information Systems
Introduction to Information System
Framework for Business End Users;
* Foundation Concepts- Fundamental behavioural and technical concepts.
* Technology - Major concepts, developments, and Management issues in IT- software, hardware
* Applications - Using emails for fast communication, internet, intranet, & extranet to gather the
information, for operations and management.
* Development - How end users or information specialist develop information systems solutions
to business problems using fundamental problem.
* Management - Effectively managing the resources and business strategies involved in using IT
and end user.
Key Terms Used in Information System ( Data, Information, Knowledge, and Wisdon)
Data - something we can collect from enviromental process.
Information - data presented in more understand form.
Knowledge - education and experience create knowledge in humans.
Wisdom - knowledge create a better human thinking.
What is a System?
- interrelated components working together toward a common goal by accepting inputs and
producing outputs in an organized transformation process.
Basic interacting components (functions)
What is an Information System?
- It provides infromation for vital business operation. Three points of information system hardware,
software, and persware.
Information Technology vs. Information Systems
- a computer information system (CIS) consists of related components like hardware, software,
people, procedures, and collections of data.
- represents the various types of hardware and software used in an information system, including
computers and networking equipment.
- procedures are instructions that help people use the systems.
- collection of application programs that perform services for the end-users. Each program
defines and manages its data.
Five types of problem;
* Separation and isolation of data
* Duplication of data - Duplication is wasteful
- Duplication can lead to loss of data integrity
* Data Dependence
* Incompatible file formats
* Fixed queries/ proliferation of application programs
Information Database Approach
- to overcome the limitations of the file-base approach
* Control of data redundancy - to eliminate the redundancy by interating the file
* Data consistency - by eliminating or controlling redundancy, the database approach reduces the
risk of inconsistencies occuring.
* More information from the same amount of data
* Sharing of data - database belongs to the entire organization and can be shared.
* Improved data integrity - provides the validity and consistency of stored data.
* Improved security - provides a protection of the data from the unauthorized.
* Enforcement of standards - enforces the necessary standards.
* Economy of scale - combining all organization's operational data into one database.
* Balance of conflicting requirements
* Improved data accessibility and responsiveness
* Increased productivity - provides all the low-level file-handling routines.
* Improved maintenance - provides a data independence.
* Increased concurrency - manage concurrent data access effectively.
* Improved backing and recovery services - provides facilities to minimize the amount of
processing that can be lost.
Component of IS
* Data - Input that the system takes to produce infromation.
* Hardware - Computer itself and its peripheral equipment; input, output, storage devices. include
data communication equipment.
* Software - Sets of instructions that tell the computer how to input, process, output and store data
* Communication networks - Hardware and software specializing in transmission and reception
of electronic data.
* People - IS professionals and users who design, construct, operate and maintain IS
* Procedures - Rules to process data, e.g. priorities in running different applications, security
measures, and routines for malfunctioning IS, etc