Lesson Notes By Weeks and Term - Senior Secondary School 1

SUBJECT: INFORMATION COMMUNICATION TECHNOLOGY

CLASS:  SS 1

DATE:

TERM: 2nd TERM

 
WEEK FIVE

TOPIC: OUTPUT DEVICE-PRINTER

Reference book: Hiit @ School, Computer Studies for Senior Secondary Education.

Content

Printer 

In computing, a printer is a peripheral which produces a text and/or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces (typically wireless and/or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are often designed to support   both local and network connected users at the same time.

Types of Printers 

1. Impact printers
2. Non-impact printers

Impact Printers

An impact printer forms characters and graphics on a piece of paper by striking a mechanism against an ink ribbon that is in physical contact with the paper. Consequent on this striking activity, impact printers generally are noisy. Examples are: Line printers, Daisy Wheel printer and Dot Matrix printers.    

Line Printers: line printers have a spinning horizontal drum that stretches the full width of the paper which is separated from it by an inked ribbon. The drum is made up of 132 thin cylinders each having a complete set of characters. Behind the paper is row of 132 hammers that strike the paper at the right moment to select the required character from the corresponding cylinder. In a way, it is able to print a complete line at a time. Line printers are used for high volume low quality output and are very noisy.

Daisy Wheel Printers: On a daisy wheel printer the complete set of characters is held on a removable wheel which consists of a central collar radiating out from which are a set of spokes, each ending in a single character. The wheel spins round to align the required character with a single hammer. The hammer and wheel assembly moves across the paper striking it through an inked ribbon. These printers can produce high quality output but are limited to the range of characters on the wheel. Changing wheels is simple, this provides alternative fonts, but it is no substitute if a wide range of fonts are required. They are quite noisy and are used for low volume office work.

Dot Matrix Printer: Dot matrix printers have a horizontally moving head with a vertical line of pins mounted inside. An inked ribbon is located between the head and the paper and as the head moves the pins strike the ribbon to from each character as series of dots. The best quality printers have heads with 24 pins and low quality ones have 9 pins (although by making two passes and shifting the head half a pin pitch between them they can effectively act as an 18 pin head). These printers can produce small dots anywhere on the paper, support graphics and have software fonts. Dot matrix printers are quite noisy but can be cheap. They are mostly for low to medium quality, low volume personal use. They are obsolete.

Non-Impact Printer        

A non-impact printer forms characters and graphics on a piece of paper without actually striking the paper.   Some spray ink, while others use pressure and heat to create images. Because these printers do not strike the paper, they are less noisy than the Impact printers. Examples are: InkJet printers, Laser Printer and Thermal printers. 

InkJet Printer: this is a type of computer printer that reproduces a digital image by propelling variably sized droplets of ink onto a page. InkJet printers are the most common type of printer and ranges from small inexpensive consumer models to very large and expensive professional machines: this is an alternative to daisy wheel printer. It can be used in advertising and public relations.

Laser Printers: in a laser printer, paper is given an electro-static charge by passing it over a charged drum and then a laser scans it discharging all clear areas. Next the paper is passed over a tray of powdered ink (toner) which is attracted to the charged areas. Finally the toner is bonded to the paper by heat or pressure. Laser printers are quite and are used for high quality low or high volume work.

Thermal Printers: it produces a printed image by selectively heating coated thermo chromic or thermal paper; when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image. Two-colour direct thermal printers are capable of printing both black and an additional colour (often red), by applying heat at two different temperatures. It prints using very small wire small wires to burn a special paper. It uses the dot matrix principle and is noiseless.

Comparative Study of Printers  

Impact Printers

Non-Impact Printers

EVALUATION

1. State THREE differences between Impact and non- impact printers.
2. Mention TWO types of printers with THREE examples each.

READING ASSIGNMENT: HiiT @ School, Computer Studies for Senior Secondary Education. Chapter Six, pages 23-25.

WEEKEND ASSIGNMENT

OBJECTIVES

1. __ printer forms characters on paper without striking the paper. a) impact b) non-impact c) line
2. Which of the printer has horizontal head with pins? a) dot matrix b) InkJet c) Laser
3. ___ printer uses heat coated thermo chromic. a) Line b) Daisy c) Thermal
4. Printer is an ___ device. a) input b) output c)input/output
5. The drum of Line printer is made up of ___ thin cylinders. a) 123 b) 132 c) 231

THEORY

1. State THREE differences between Impact and non- impact printers.
2. Mention TWO types of printers with THREE examples each.
3. Explain the TWO types of printers. 

TOPIC SIX

TOPIC: COMPUTER SYSTEM SOFTWARE-I

Reference book: Hiit @ School, Computer Studies for Senior Secondary Education.

CONTENT

Software, by definition, is the collection of computer programs, procedures and documentation that perform different tasks on a computer system. The software is a program written by a programmer or software developer. A program is a list if instructions given to the computer to perform a particular task. The software is the intangible part of the computer system, though they come in CDs according to today’s standard.

Types of Software

There are two types of software: system software and application software.

System Software: system software is computer software designed to operate the computer hardware and to provide and maintain a platform for running application software. The basic examples of system software are: operating system, utility software, and resource management software and language translators.

Utility Software: they are used for general house-keeping functions of the computer such as backing up files, repairing the computer, copying, sorting and printing of data.

Back-up software: is software that keeps duplicate copies for safety and future retrieval.

Anti-virus: software to combat computer viruses.

Fire-wall: software to provide unwanted down-loaded or set-up software that could cause changes to computer register.

Editors: Software to type source –code programs.

RMS (resource management software)-software to enhance computer performance, speed and efficiency e.g. Scandisk, check disk, defragmentation (defrag).

EVALUATION

1. Define system software 
2. List and explain 4 different types of system software.  

READING ASSIGNMENT: HiiT @ School, Computer Studies for Senior Secondary Education. Chapter Seven, pages 26

WEEKEND ASSIGNMENT

OBJECTIVES

1. A collection of programs and procedures is referred to as ___ a) software b) code c) data
2. ____ software combats computer viruses. a) ante-virus b) anti- virus c) software 
3. Software that enhances computer performance is known as __. a) Resource management software 
4. b) Database management software c) data processing software. 
5. ____ software is used for backing up files. a) Utility b) system     c) application
6. A person who writes software is called ___ a) software developer b) software designer 
7. c) Software operator

THEORY

1. Explain utility software.
2. State 4 examples of utility software.

TOPIC SEVEN

TOPIC: COMPUTER SYSTEM SOFTWARE-II

Reference book: Hiit @ School, Computer Studies for Senior Secondary Education.

CONTENT

Examples of Utility programs

• Norton utilities
• Anti-virus
• Windows Explorer
• Scandisk
• Editors

Language Translators: A language translator is a software that converts programs written in a source code, into an object code that a computer understands. Examples of high level programming language that requires translators are BASIC, FORTRAN, COBOL, PASCAL, etc.

Types of Translators

The three types of language translators are: 

Assembler: An assembler converts an assembly program into machine code also known as the object code or object program.

Compliers: A compiler is a program that translates a high level language into machine code before execution. Example, the Turbo Pascal compiler translates a program written in Pascal into machine code that can be run on a PC.

Interpreters: An interpreter is also a program that translates high-level sources code into executable code during execution. However the difference between a compiler and an interpreter is that an interpreter translates one line at a time and then executes it. It is faster than compiler and translates per line unlike compiler.

EVALUATION

1. Define Language translator.
2. List THREE examples of utility software.

READING ASSIGNMENT: HiiT @ School, Computer Studies for Senior Secondary Education. Chapter Seven, pages 26

WEEKEND ASSIGNMENT

OBJECTIVES

1. _____ converts an assembly program into machine code. a) Interpreter b) assembler 
2. c) Program
3. Another name for object code is a) object program b) object software c) code software
4. A program that translates high-level sources code into executable code during execution is 
5. a) interpreter     b) assembler         c) compiler
6. Which of these is a language translator?    a)   Interpreter    b) decoder     c) compiler 
7. _____ program that translates a high level language into machine code before execution.
8. a) Interpreter     b) assembler         c) compiler

THEORY

1. List and explain the THREE types of Language translators.
2. State TWO examples of high level language.

TOPIC EIGHT

TOPIC: OPERATING SYSTEM

Reference book: Hiit @ School, Computer Studies for Senior Secondary Education.

CONTENT 

An operating system (OS) is software consisting of programs and data that runs on computers, manages computer hardware resources and provides common services for execution of various application software.

Types of Operating systems

1. Graphical User Interface
2. Command based or Command Line Interface,
3. Single User
4. Multi-user
5. Network Operating system.

GUI-Graphical User Interface: Operating systems of this class have interactive features like pictures, diagrams, boxes, bars, bars, and button which make them user friendly, easier to use, etc. Examples of this operating system include: MS-Windows, Linux-windows, and Unix-windows.

CLI command line interface or Command Based Operating Systems: communicate with hardware and other software via a command utility understudied by the user. Special commands are used to access their features. Their operation requires an expert; painstaking observation. Therefore a novice cannot easily work with them. Examples of this operating system are: MS- DOS, UNIX, Linux-DOS, etc.  

Single User Operating System (SUOS)-: a single user operating system is an operating system that is designed to manage and allocate computer resource (hardware + software resources) to one user. Examples are: MS-DOS, some versions of windows operating system (WOS), etc.

Multi User Operating system (MUOS): is an operating system that allows concurrent access by multiple users to a computer. It is designed to manage and allocate common computer resource to more than one user and to more than one computer for sharing purpose. This operating system allows more than one user to run several programs at the same time. The process of running more than one program concurrently or at the same time is known as multiprogramming. GUI or Command based operating system can also be classified as a multi user operating system. Examples are: UNIX, XENIX, ZENIX, LINUX etc.

Network Operating System (NOS): a network operating system links computers and users together to share resources and communicate with one another. Common examples are: Windows NT, Widows Server 2003, Novell Netware, LINUX, etc.

Examples of operating system

Common examples of operating systems are:

MS Windows (Microsoft Window): it is a single user GUI operating system. That is, only one person can use the system at a time. 

Versions of Windows operating system: Windows ’95, Windows ’98, Windows 2000, Windows ME (Millennium Edition), Windows XP (Experience), Windows NT (New Technology), Windows Vista, Windows 7, etc.

 EVALUATION

1. Define Operating System.
2. List FIVE types of Operating System.

READING ASSIGNMENT: HiiT @ School, Computer Studies for Senior Secondary Education. Chapter Seven, pages 26-28.

WEEKEND ASSIGNMENT

OBJECTIVES

1. The following are versions of Windows operating systems 
2. a) Windows ’95 b) Windows ’98    c) Ms-Access
3. An operating system that is designed to manage computer resources to users 
4. The process of running more than one program concurrently is known as
5. a) Multi-programming b) NOS     c) MUOS
6. ___ operating system links computers and users together to share resources.
7. a) LINUX b) NOS     c) MUOS
8. An operating system with interactive features is called __. 
9. a) GUI b) SUOS    c) MUOS

THEORY

1. List THREE types of Operating System with TWO examples each.
2. State the uses and functions of the types of Operating System listed above. 

TOPIC NINE

TOPIC: COMPUTER APPLICATION SOFTWARE

Reference book: Hiit @ School, Computer Studies for Senior Secondary Education.

CONTENT 

Application software: are written to perform specific functions. The application software is written to solve a particular problem. 

Types of Application Software

The two types of application software are: user application software and application packages.

User Application Software: is designed to meet the need of specific users. The software may be written for the user within an organization or contracted to external programmers. This type of software is often referred to as tailor-made/purpose written or bespoke application software.

Application packages: these are commercialized software designed to perform various categories of user functions.

Categories of Application Packages

Application packages can be classified into: application specific and general purpose application packages.

Application Specific: these application packages are programs designed to carry out a specialized task. 

General Purpose: these are designed to provide users with general set of facilities to handle a wide variety of problems.

Packages for specialized areas are based on the categories of application packages. These are

Application Specific: the categories of application specific packages are: payroll programs, education Management software, Accounting software, Banking software, hospital management software, Statistical software, Web design software, etc. 

General Purpose: the following are categories of general purpose application packages: Word processing, Graphic software, Games software, Database software, Spreadsheet software, etc

EVALUATION

1. Mention any FOUR categories of application packages you know.
2. State and explain the TWO types of application software.

READING ASSIGNMENT: HiiT @ School, Computer Studies for Senior Secondary Education. Chapter Eight, pages 29.

WEEKEND ASSIGNMENT

OBJECTIVES

1. The following are types of application software except 
2. a) Web      b) user         c) application package
3. ____ application software is designed to meet the need of specific users. 
4.   a) User     b) graphic     c) Word 
5. Which of these software is an example of application specific packages?
6. a) Accounting    b) Statistical        c) Ms-Word
7. ___ is commercialized software designed to perform various users’ functions.
8. a) Application package    b) user application    c) operating system
9. ____ software is also referred to as tailor-made application software. 
10. a) Application package b) user application    c) general purpose   

THEORY

1. Define application software.
2. List FIVE specialized packages.