Software part two

1.       Describe the following types of common utility programs.

(a)    Antivirus (2)

An antivirus is used to prevent or remove Viruses on your computer.

(b)   Disk derangement (2)

Disk derangement is a tool that rearranges the data on your volume and reunites fragmented data so your computer can run more efficiently.

2. (a) Explain what is meant by ‘off-the-shelf’ software.

Software you can buy online and download to your computer.

(b)List some of the advantages and disadvantages of using off-the-shelf-software.

Advantage:  They are reasonably priced, they are easy to access and you are able to get support if needed.

Disadvantages:  You may have to pay for certain features.

3. (a) Explain what is meant by ‘custom-written’ or ‘bespoke’ software.
Software which can be customized for you.

 (b) List some of the advantages and disadvantages of using custom-written software.

Advantages: That it has the features that you want and no-one else has it

Disadvantages: It cost a lot of money and there may not be any support. 

4. (a)Explain what is meant by ‘open-source’ software.

Users can see how the program works and they are able to change it if they want.

(b)   List some of the advantages and disadvantages of using open-source software.

Advantages: It is usually free and people can modify it to make it their own and also to fix bugs. 
Disadvantages: It is very unlikely to get any support.

3. (a) Explain what is meant by ‘proprietary’ software.
Where computer software is licensed under exclusive legal right of the copyright holder with the intent that the licensee is given the right to use the software only under certain conditions. 

(b) List some of the advantages and disadvantages of using proprietary software.

Advantage : If there is a problem you can quickly fix it.
Disadvantage:

5. A person running a small business has decided to use off-the-shelf software to help with providing invoices and letters.

 Describe two advantages to the owner of using off-the-shelf software rather than having it custom made for their business. (4)

Advantage 1: They don't need all of the features if they only need it for letters and invoice.

Advantage 2: Its cheaper. 

6. A school has decided to install an open-source software suite on all of the computers rather than commercial, proprietary software.

 Describe two advantages for the school in using open-source software. (4)

Advantage 1: Its free

Advantage 2: They can get all the features needed. 

Utility Software

1.      What is Utility Software?

- Utility software is system software designed to help analyse, configure, optimize or maintain a computer. Utility software usually focuses on how the computer infrastructure operates.

2.      What is Anti-virus Software and how does it work?

- Antivirus software is used to safeguard a computer from malware, including viruses, computer worms, and Trojan horses. Antivirus software may also remove or prevent spyware and adware, along with other forms of malicious programs.

3.      Viruses, Trojan horses, and worms

-  Viruses, worms and Trojan Horses are all malicious programs that can cause damage to your computer, but there are differences among the three, and knowing those differences can help you better protect your computer from their often damaging effects.

4.      What is a firewall and why would we use one?

 - If your PC is connected to the Internet, you are a potential target to an array of cyber threats, such as hackers, key loggers, and Trojans that attack through unpatched security holes, a firewall can prevent this from happening.

5.      What is encryption and why would we use it?

- Encryption is the most effective way to achieve data security. To read an encrypted file, you must have access to a secret key or password that enables you to decrypt it.

6.      What is disc management software and why do we need it?

- Disk Management is an extension of the Microsoft Management Console that allows full management of the disk-based hardware recognized by Windows. Disk Management is used to manage the drives installed in a computer - like hard disk drives (internal and external),optical disk drives, and flash drives.

7.      What is disc defragmentation and how does it work?

- Disk Defragmenter is a tool that rearranges the data on your volume and reunites fragmented data so your computer can run more efficiently. In this version of Windows, Disk Defragmenter runs on a schedule so you don't have to remember to run it, although you can still run it manually or change the schedule it uses.

8.      What is system maintenance software and why do we need it?

9.      What are development or dev tools and why do we use them?

 - The Dev Tools application, you can enable a number of settings on your device that will make it easier to test and debug your applications. The Dev Tools application relies on a number of permissions that are not available for third party applications. If you'd like to install the Dev Tools application on a real development device, you'd have to build a system image for that device and sign the Dev Tools application with the same key as used for the system image

10.  Explain what an assembly language is and what we use an assembler for.

 - A low-level symbolic code converted by an assembler.

Functions of an operating system

1) Explain what is meant by an ‘operating system’.

 - It is necessary to run all computing devices.

2) When is the operating system loaded?

- When one of the computers is loaded up 

3) List some commonly used operating systems.

- Commonly used operating systems are, Mac, Windows and Linux

4) Explain how the operating system controls the software and hardware on the computer.

-  It uses device driver to translate the specific instruction to save that hardware.

5) Describe two types of user interfaces provided by the operating system.

- Command Line Interface - It used to be the only way to operate the computer. Also it is fast to get things done and does not need a powerful computer. 

- Menu Driven Interface - It is often seen on computers which have limited input device. simple to navigate and you cannot edit the menu. 

6) Explain what is meant by a ‘multitasking operating system’.

-The OS controls multi-tasking making it look like the computer is running two programs at once. It does this by switching the programs very quickly. The CPU is so fast there are times when the ram can’t keep up (video buffering) so the CPU is instructed by the OS to do something this time.

Software

Software is the programs that run on a computer
This includes: application software and system software.
System software - controls and makes use of hardware.
Application software - programmes which do real world tasks the user wants to do.
Software is written by programmes using various programming languages.

In 1937 Alan Turning thought of a device which would do any task when it was given the instructions to do it.

The instructions are loaded into the RAM from the hard drive and fetched - decoded and executed by the CPU. These instructions are program i.e software.

The CPU only understands binary - machine code (low-level language) long winded and difficult. So programmers use high-level languages to set out algorithms.

Functions of the operating system
The Operating System is necessary as it is to run all computing devices

The operating system sits between your applications and the hardware of your computer.

The operating system deals with controlling all aspects of the computer.

This makes it easier to write applications.

The kernel is the lowest level of an OS and controls the hardware.

Functions - Manages hardware

It manages the hardware and software resources of the system.

In a desktop computer, these resources include such things as the processor, memory, disk space and more.

For example, when you wish to save a document, the application passes the document to the Operating System (OS).

The OS needs to use different instructions to save to a hard disc compared with a solid state drive.

The OS uses special software called a device driver to translate the specific instructions to save to that hardware.

Each different piece of hardware will have a device driver to communicate between OS and the hardware.

Peripheral management 

The computer has peripherals in order to input output and store data. The signal which controls them is a device driver which is controlled by the software. Each peripheral has its own driver depending on the manufacturer. These are some generic device drivers in windows 7/8.

The application software doesn’t need to know about the devices it just passes on requests from the user to the driver.

Interrupt signal is generated by a program which tells the OS to stop a program using a device and make the CPU do a task for another program with the device.

User settings

Applets - A small application that does a single task. The OS has applets built in to allow the user to e.g. change the screen resolution

Firmware

Firmware is the initial start up before device drivers are loaded on. This is stored permanently on ROM chips e.g. BIOS - basic input output system, which does the initial start-up of a computer.

Firmware also runs on simple devices such as a TV remote or a camera.

Server

The word server applies to the hardware (the computer and software.

Server software responds to the requests of other programed (clients). It’s used on the internet and on smaller networks like we have in school, e.g. when we ask to print - the server software processes the request and delivers the data to the client.

Functions - multitasking

The OS controls multi- tasking, making it look like the computer is running more than one program at once.

It does this by switching between programs very quickly

The CPU is so fast there are times when the RAM can’t keep up (video buffering) so the CPU is instructed by the OS to do something in this time.

Functions - Memory Management

The OS controls the memory management, allocating RAM space to programmes.

It determines how much memory each app has and what to do if memory becomes full.

It manages virtual RAM

It tracks where data and programmes are at any one time ti make efficient use of the memory and ensure nothing is the lost.

Security

OS must protect processes from each other and users from each other because PCs are used by multiple users at home or on a network and on the Internet.

It tracks who owns each file and what privileges the user has on each file/folder.

Passwords to login allow you to protect your phone from other users but also allow you to use networked computers on your own profile.

Functions - User Interface

The OS provides a user interface.

This is what the user sees when they wish to use the computer system.

There are different types of user interface, each with their own advantages and dis advantages.

User Interface – Command Line Interface

This is used to be the only way to operate a computer

Commands are typed in at a prompt to run programes or perform actions.

Does not need a powerful computer.

Fast to get things done.

Not suitable for beginners as you need to know the commands before you can operate the computer. Used by technicians because it is quicker.

User Interface – Menu Driven Interface

Often seen on devices where the input device is limited (e.g. a TV remote)

As all the options are there to be seen, it is much easier for novices.

Simple to navigate and easy to determine what to do.

Some options take you further menus while final options perform the actions.

Cannot edit the menu so you can make customisations

Voice Recognition

This is still evolving but is becoming more widely used e.g. call centres ask the user to say numbers and or yes/no. Apple iPhone has voice recognition as part of the OS - SIRI

Windows

Windows OS currently 8.1 keeps the entire GUI and all applications looking similar so that user can easily use them. They all use code that is part of Windows itself.

It has a huge range of capabilities far greater than the OS itself.

MAC  OS

On PC this is Yosemite. This is based on a UNIX system and has led to the iOS for mobile devices. It is a propriety system which has enabled new ways of thinking about how a user interacts with OS.

Linux

This is an open source range of OS’ based on the UNIX works on command line but new versions of LINUX fun on a GUI. It is a small OS and is therefore fast and uses led memory. It is very versatile and is used on servers, and mobile devices – ANDROID.