Operating Systems for your Desktop PC.

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Utility Software. Utility software or utility programs are some small programs which performs specific task, usually related to managing a computer, its devices, or its programs. Most operating systems include several utility programs. Also, you can buy them as stand-alone software that offer improvements over the ones supplied with the OS. Following are some of the specific tasks done by commonly used utility programs:

Viewing files

Compressing files

Diagnosing problems

Scanning disks

Defragmenting disks

Uninstalling software

Backing up files and disks

Checking for viruses

Displaying screen savers

Application Software

Accordingly, the second major class of Software is the Application Software. Application software consists of programs designed to perform specific tasks of users. Application Software, also called a software application or an application, can be used for the following purposes, among others:

As a productivity/business tool

To assist with graphics and multimedia projects

To support household activities, for personal business, or for education

To facilitate communications

Software Package.Based on the purposes as listed above, the application software is three-fold namely General Purpose, Special purpose, and Bespoke. Let us look at each type of applications software briefly.

Special Purpose Application Software.

Special Purpose Application Software is the software created for execution of a single specific task. Some examples are Chess game, calculator, camera application in your mobile phone which allows you only to capture and share pictures, web browsers, media players, calendar programs.

Evolution of operating systems. Classification of operating systems, including for mobile devices.

What is Windows 7? It is redesigned with Windows Shell with a new taskbar. Windows 7 includes a number of new features, such as advances in touch and handwriting recognition, support for virtual hard disks, improved performance on multi-core processors, improved boot performance, Direct Access, and kernel improvements.

Versions of Windows 7.

1. Home Premium makes it easy to create a home network and share all of your favoritephotos, videos, and music.

2. Professional is a great choice for home and for business. Using Windows 7 professional, You can run many Windows XP productivity programs in Windows XP Mode and recover data easily with automatic backups to your home or business network. You can also connect to company networks effortlessly and more securely with Domain Join. With all the exciting entertainment features of Windows Home Premium.

3. Ultimate is the most versatile and powerful edition of Windows 7. It combines remarkableease-of-use with the entertainment features of Home Premium and the business capabilities of Professional, including the ability to run many Windows XP productivity programs in Windows XP Mode. For added security, you can encrypt your data with BitLocker and BitLocker-To-Go. And for extra flexibility, you can work in any of 35 languages. Get it all with Windows 7 Ultimate.

System requirements

Windows 7 requires the following computer hardware:

32 Bit		64 Bit
A Processor of 1 GHz or faster 32-bit	A Processor of 1 GHz or faster 64-bit
(x86)		(x64)
At least 1 GB of RAM memory	At least 2 GB of RAM memory
A hard disk with at least 16GB space	A hard disk with at least 20GB space
available		available.
DirectX® 9 graphics processor with		DirectX® 9 graphics processor with
WDDM or higher driver		WDDM or higher driver
A DVD drive from which to install		A DVD drive from which to install
Windows.		Windows.
A monitor, keyboard, and mouse or		A monitor, keyboard, and mouse or
other pointing device.		other pointing device.

Table 2- Windows 7 Requirements

Basic Operations in Windows7. Let us have a look at the basic operations available with Windows 7. This knowledge will be helpful to you to make working with your computer easy.

First, we will learn about some required fundamental skills before performing basic operations available with your operating systems.

Log on to your computer. The process of starting a computer session is called logging on. When you start the computer, Windows displays a Welcome screen containing links to each of the computer's active user accounts. (If your computer is part of a domain, you will need to press Ctrl + Alt + Delete to display the Welcome screen.) You select your user account and, if your account is password protected, enter your password to log on to the computer. See Table 3 below for the login interface. When logging on to a computer which is part of a domain, you will always enter your domain credentials.

Brief descriptions of each component are given below.

N	Name	Brief Description

1	Desktop	Work area on which you see your programs
2	Start Menu	Let you open programs available in your computer
3	Task Bar	Let you launch and monitor running programs
4	Notification area	A portion of the taskbar that provides a temporary source for
		notifications and status.
5	Task Buttons	Currently opened programs/applications
6	Desktop Icons	Icons that belongs to and leads you to important parts of the
		computer
7	Shortcut Icons	Easy way to access programs
8	Windows Gadgets	Popular mini-programs
	Table 3: Components of Windows 7 User Interface

Questions:

1. What is Software?

2. Differentiate System software and Application software.

3. What are the responsibilities of Operating Systems?

4. Define the following with suitable examples.

Single–user OS

Multi-user OS

5. What are utility programs? Define some tasks performed by them.

6. What is meant by library programs?

7. What are program language translators? Briefly describe three translating approaches.

8. State the advantages and disadvantages of Bespoke Application Software.

References

2. Lorenzo Cantoni (University of Lugano, Switzerland) James A. Danowski (University of Illinois at Chicago, IL, USA) Communication and Technology, 576 pages.

3. Craig Van Slyke Information Communication Technologies: Concepts, Methodologies, Tools, and Applications (6 Volumes). ISBN13: 9781599049496, 2008, Pages: 4288

4. Utelbaeva A.K.,Utelbaeva A.K. Study guide for lectures on discipline “Computer science”, Shimkent 2008, 84 pages.

Lecture № 4. Human-computer interaction.

Purpose: to work with a system, the users need to be able to control the system and assess the state of the system.

Plan:

1. User interface as means of human-computer interaction. Usability of interfaces.

2. Types of interfaces: command line interface, text interface, graphic interface.

3. Physical and mental characteristics of the user. Development stages of the user interface. Types of testing of interfaces (testing of users). Perspectives of development of interfaces.

1.User interface as means of human-computer interaction. Usability of interfaces.

Human–computer interaction (commonly referred to as HCI) researches the design and use of computer technology, focused on the interfaces between people (users) and computers. Researchers in the field of HCI both observe the ways in which humans interact with computers and design technologies that let humans interact with computers in novel ways.

Humans interact with computers in many ways; and the interface between humans and the computers they use is crucial to facilitating this interaction. Desktop applications, internet browsers, handheld computers, and computer kiosks make use of the prevalent graphical user interfaces (GUI) of today. Voice user interfaces (VUI) are used for speech recognition and synthesising systems, and the emerging multi-modal and gestalt User Interfaces (GUI) allow humans to engage with embodied character agents in a way that cannot be achieved with other interface paradigms. The growth in human-computer interaction field has been in quality of interaction, and in different branching in its history. Instead of designing regular interfaces, the different research branches have had different focus on the concepts of multimodality rather than unimodality, intelligent adaptive interfaces rather than command/action based ones, and finally active rather than passive interfaces

The Association for Computing Machinery (ACM) defines human-computer interaction as "a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them". An important facet of HCI is the securing of user satisfaction (or simply End User Computing Satisfaction). "Because human–computer interaction studies a human and a machine in communication, it draws from supporting knowledge on both the machine and the human side. On the machine side, techniques in computer graphics, operating systems, programming languages, and development environments are relevant. On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology, social psychology, and human factors such as computer user satisfaction are relevant. And, of course, engineering and design methods are relevant."Due to the multidisciplinary nature of HCI, people with different backgrounds contribute to its success. HCI is also sometimes termed human–machine interaction (HMI), man–machine interaction (MMI) or computer–human interaction (CHI).

Poorly designed human-machine interfaces can lead to many unexpected problems. A classic example of this is the Three Mile Island accident, a nuclear meltdown accident, where investigations concluded that the design of the human–machine interface was at least partly responsible for the disaster. Similarly, accidents in aviation have resulted from manufacturers' decisions to use non-standard flight instrument or throttle quadrant layouts: even though the new designs were proposed to be superior in basic human–machine interaction, pilots had already ingrained the "standard" layout and thus the conceptually good idea actually had undesirable results.

Human–computer interaction studies the ways in which humans make, or don't make, use of computational artifacts, systems and infrastructures. In doing so, much of the research in the field seeks to improve human-computer interaction by improving the usability of computer interfaces. How usability is to be precisely understood, how it relates to other social and cultural values and when it is, and when it may not be a desirable property of computer interfaces is increasingly debated.

The human–computer interface can be described as the point of communication between the human user and the computer. The flow of information between the human and computer is defined as the loop of interaction. The loop of interaction has several aspects to it, including:

· Visual Based :The visual based human computer inter-action is probably the most widespread area in HCI research.

· Audio Based : The audio based interaction between a computer and a human is another important area of in HCI systems. This area deals with information acquired by different audio signals.

· Task environment: The conditions and goals set upon the user.

· Machine environment: The environment that the computer is connected to, e.g. a laptop in a college student's dorm room.

· Areas of the interface: Non-overlapping areas involve processes of the human and computer not pertaining to their interaction. Meanwhile, the overlapping areas only concern themselves with the processes pertaining to their interaction.

· Input flow: The flow of information that begins in the task environment, when the user has some task that requires using their computer.

· Output: The flow of information that originates in the machine environment.

· Feedback: Loops through the interface that evaluate, moderate, and confirm processes as they pass from the human through the interface to the computer and back.

· Fit: This is the match between the computer design, the user and the task to optimize the human resources needed to accomplish the task.

Topics in HCI include:

Definition of User Interface.

In computer science and human-computer interaction, the user interface (of a computer program) refers to the graphical, textual and auditory information the program presents to the user. The user employs several control sequences (such as keystrokes with the computer keyboard, movements of the computer mouse, or selections with the touchscreen) to control the program.

2. Types of interfaces: command line interface, text interface, graphic interface.

There exist several types of user interfaces.

· Command-Line Interface (CLI): The user provides the input by typing a command string with the computer keyboard and the system provides output by printing text on the computer monitor .

A Command Line Interface allows the user to interact directly with the computer system by typing in commands (instructions) into a screen

You cannot just type in any kind of instruction of course, because the computer will only react to a definite set of words.

These commands are very specific, for example in DOS you could type in:

copy c:\item.txt d:\

That tells the machine to copy the file 'item.txt' that resides in the root directory of drive C: into the root directory of drive D:\

Many commands have what are called 'switches'. These are extra parameters or flags which add extra functionality to the command. For example:

»Dir gives a directory listing

»Dir /w gives the listing across the page

»Dir /s includes the sub directories

»Dir /p pauses at the bottom of every page

Before Windows was developed, this type of user interface was what most people used to get the computer to follow instructions. Nowadays, very few people have the knowledge to be able to use a command line interface.

An example of this type of interface is DOS (Disk Operating System).

Sometimes referred to as the command screen or a text interface, the command line or Windows command line is a user interface that is navigated by typing commands at prompts, instead of using the mouse. For example, the Windows folder in a Windows command line (MS-DOS) is C:\Windows> (as shown in the picture) and in Unix or Linux, it may be % or >. Unlike a GUI operating system, a command line only uses a keyboard to navigate by entering commands and does not utilize a mouse for navigating.

Because a command line interface requires unique commands, this interface is often more difficult to learn because of the need to memorize dozens of different commands. However, a command line operating system can be a very valuable resource and should not be ignored. For example, users who have Microsoft Windows may find trivial tasks, such as renaming 100+ files in a folder, a very difficult task. However, renaming 100+ files in a directory can be done in less than a minute with a command entered into the command line.

Advantages and Disadvantages
Advantages	Disadvantages
If the user knows the correct commands then this type of interface can be much faster than any other type of interface	For someone who has never used a CLI, it can be very confusing
This type of interface needs much less memory (RAM) in order to use compared to other types of user interfaces	Commands have to be typed precisely. If there is a spelling error the command will fail
This type of interface does not use as much CPU processing time as others	If you mis-type an instruction, it is often necessary to start from scratch again
A low resolution, cheaper monitor can be used with this type of interface	There are a large number of commands which need to be learned - in the case of Unix it can be hundreds
A CLI does not require Windows to run	You can't just guess what the instruction might be and you can't just 'have a go'.

Table 4- Advantages and Disadvantages

Text interface with menus

A text interface can be made easier to navigate using menus created with text and ASCII extended characters. For example, many command line text editors have some type of interface with menus and shortcut keys that make navigating the file being edited easier. The picture below is an example of the MS-DOS editor used to edit files while at the MS-DOS or Windows command line.

WIMP or GUI Interface

A graphical user interface (GUI) is the most common type of user interface in use today. It is a very 'friendly' way for people to interact with the computer because it makes use of pictures, graphics and icons - hence why it is called 'graphical'.

A GUI (pronounced gooey) is also known as a WIMP interface because it makes use of:

Windows - a rectangular area on the screen where the commonly used applications run

Icons - a picture or symbol which is used to represent a software application or hardware device

Menus - a list of options from which the user can choose what they require

Pointers - a symbol such as an arrow which moves around the screen as you move your mouse. Helps you to select objects.

Advantages and Disadvantages
Advantages	Disadvantages
This type of user interface is easy to use, especially for a beginner	GUIs take up a much larger amount of hard disk space than other interfaces
It is easy to explore and find your way around the system using a WIMP/ GUI interface	They need significantly more memory (RAM) to run than other interface types
You do not have to learn complicated commands	They use more processing power than other types of interface
There are usually a reasonable 'help' system included with WIMP interfaces	They can be slow for experienced programmers to use. These people often find CLI interfaces much faster to use
You get the benefits of WYSIWYG
They let you exchange data between different software applications

Table 5- Advantages and Disadvantages

A GUI is an interface built around visual (graphical) things:

· Windows are regions of the screen used to display information

· Icons are small pictures that are used to represent folders, software, etc.

· Menus are lists of options the user can select from

· A pointer is an arrow that can be moved around the screen and is used to select things

Windows XP is an example of an operating system with a GUI.

GUIs are quite easy to use due to the visual nature of the interface – the user has lots of visual clues as to what things do.

However, to display all of the nice graphics required by a GUI takes a lot of computing power so quite a powerful computer is needed.

· Graphical User Interface (GUI): The use of pictures rather than just words to represent the input and output of a program. Input is accepted via devices such as keyboard and mouse.

Many years ago when computers were not very powerful they could not display the colourful graphics required for a GUI. The only interface available to most computer uses was the ‘command line’.

The user would see nothing but a black screen. They would have to type a command to make anything happen.

To copy a text file called NOTES from a floppy disc to the hard drive the user would have to type:
> COPY A:\NOTES.TXT C:\

The user would have to learn a whole set of strange commands so that they could make use of the computer system. Plus it was not very interesting look at – no visual clues to tell you what to do next.

3. Physical and mental characteristics of the user. Development stages of the user interface. Types of testing of interfaces (testing of users). Perspectives of development of interfaces.
This meant computers used to be quite difficult to use, so this type of interface is only really suitable for expert users.

The system that people use to interact with a computer (to give it commands, to see the results of those commands, etc.) is known as the user interface.

Graphical user interface

In computer science, a graphical user interface (GUI /ɡuːiː/), is a type of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, instead of text-based user interfaces, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of command-line interfaces (CLIs), which require commands to be typed on a computer keyboard.

The actions in a GUI are usually performed through direct manipulation of the graphical elements.^[4] Beyond computers, GUIs are used in many handheld mobile devices such as MP3 players, portable media players, gaming devices, smartphones and smaller household, office and industrial equipment. The term GUI tends not to be applied to other lower-display resolution types of interfaces, such as video games (where head-up display (HUD) is preferred), or not restricted to flat screens, like volumetric displays^[6] because the term is restricted to the scope of two-dimensional display screens able to describe generic information, in the tradition of the computer science research at the Xerox Palo Alto Research Center (PARC).

Post-WIMP interfaces

Smaller mobile devices such as personal digital assistants (PDAs) and smartphones typically use the WIMP elements with different unifying metaphors, due to constraints in space and available input devices. Applications for which WIMP is not well suited may use newer interaction techniques, collectively termed post-WIMP user interfaces. As of 2011, some touchscreen-based operating systems such as Apple's iOS (iPhone) and Android use the class of GUIs named post-WIMP. These support styles of interaction using more than one finger in contact with a display, which allows actions such as pinching and rotating, which are unsupported by one pointer and mouse.

Human interface devices, for the efficient interaction with a GUI include a computer keyboard, especially used together with keyboard shortcuts, pointing devices for the cursor (or rather pointer) control: mouse, pointing stick, touchpad, trackball, joystick, virtual keyboards, and head-up displays (translucent information devices at the eye level).

There are also actions performed by programs that affect the GUI. For example, there are components like inotify or D-Bus to facilitate communication between computer programs.

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