4.1 Types of software and interrupts

Question 1

Define and tell me what system software does?

Answer 1

• The system software provides the services that the computer requires, including the operating system and utility software.
• It controls and manages computer hardware and runs the application software.
• It provides the interface between the computer hardware and the user applications.

Question 2

What are some examples of System software?

Answer 2

• Operating system
• Utility programs
• Compilers
• Device drivers
• File management system
• Linkers

Question 3

What is application software, and what is its function?

Answer 3

• The application software provides the services that the user requires.
• It allows the user to carry out specific tasks such as creating a document or an image.

Question 4

What are some examples of application software?

Answer 4

• Database
• Spreadsheet
• Word processor
• Apps
• Internet browser
• Game software
• Photo editing software

Question 5

What is a ‘Word processor’ and what is its function?

Answer 5

• It is used to manipulate a text document.
• FUNCTION: Creating, editing, saving & manipulating text + copy and paste functions

Question 6

What is a ‘Spreadsheet’ and what is its function?

Answer 6

• It is used to organize and manipulate numerical data.
• FUNCTION: Use of formulas to carry out calculations + Ability to produce graphs

Question 7

What is a ‘Database’ and its function?

Answer 7

• It is used to organize, manipulate, and analyze data.
• FUNCTION: Ability to carry out queries on database data and produce a report + Add, delete, and modify data in a table

Question 8

What is an ‘Operating system’ and its functions?

Answer 8

• It provides an interface between the user and the hardware.
• FUNCTION: managing files, managing memory, providing an interface, handling interrupts

Question 9

What is a ‘Utility software’? (UTILITIES)

Answer 9

• They are a part of the operating system of a computer.
• These are additional programs that help to maintain or configure the system.

Question 10

What are the functions of a utility software?

Answer 10

• Back-up Software
• Security Software
• Disk Cleanup
• Virus checker (Anti-virus software)

Question 11

What is the function of the virus checker(utility software)?

Answer 11

• It scans files stored on a computer system for malicious code.
• It scans files when they enter the system
• It sets up a schedule for virus-checking.

Question 12

When does the virus checker perform a check?

Answer 12

• It checks for viruses when an external storage device is connected, e.g., a memory stick.
• It checks for viruses when a file or web page is accessed or downloaded.

Question 13

What is ‘Disk Cleanup’ and its function?

Answer 13

• It releases storage by removing unwanted or temporary files.
• This improves system performance as memory is saved from unwanted data.

Question 14

What is the function of backup software?

Answer 14

• It makes a copy of data at regular intervals (e.g., daily, weekly, etc.)
• The copy of data is stored in a different location or elsewhere
• It may encrypt the backup files.

Question 15

What is the function of security software?

Answer 15

• It manages access control and user accounts (using user IDs and passwords).
• It protects network interfaces, e.g., through the use of firewalls.

Question 16

How do disk formatter, disk contents analysis, and disk repair utilities work together?

Answer 16

• The disk contents analysis checks for errors/problems with the disk.
• The disk repair attempts to fix the errors.
• The disk formatter prepares the disk for initial use again.

Question 17

What are examples of an Operating System(OS)?

Answer 17

• Microsoft Windows
• Apple Mac OS
• Google Android
• Apple’s iOS

Question 18

Why does a personal computer(PC) need an operating system(OS)?

Answer 18

• It performs a number of basic tasks, including controlling hardware.
• It allows the user to communicate with the computer using hardware.
• It provides the user with a user interface.

Question 19

What is an interrupt?

Answer 19

• It is a signal sent from a device or from software to the microprocessor that attention is required.

Question 20

What is the software in the computer that will receive and manage all interrupt signals?

Answer 20

OPERATING SYSTEM (OS)

Question 21

Why are interrupts needed?

Answer 21

• They are needed to stop the current process
• They are needed to allow multitasking.
• They are needed for efficient processing

Question 22

What would happen if Interrupt signals were not used in the computer?

Answer 22

• The computer will not be able to multitask.
• The errors may not be dealt with.

Question 23

Examples of software interrupts?

Answer 23

• Runtime error, e.g., division by zero
• A running program needs input
• A buffer is full
• Stack overflow

Question 24

Examples of hardware interrupts?

Answer 24

• Mouse button is clicked
• Moving the mouse
• Pressing a key on keyboard
• Printer runs out of paper
• Printer runs out of ink

Question 25

When are Interrupts detected in the Fetch-Execute cycle?

Answer 25

- The interrupts are detected at the start or end of a Fetch-Execute cycle.

Question 26

How does the processor handle an Interrupt using an Interrupt Service Routine?

Answer 26

- When an interrupt signal is received, the processor checks the priority of the interrupt. - If interrupt priority is lower than the current process, then it carries on with the current task. - If the interrupt priority is higher than the current process, then it stops to service the interrupt. - The processor saves the current contents of the Program Counter (PC) and other registers. - It identifies the location/source and type of interrupt.

Question 27

What is the role of an interrupt in generating a message on the computer that the paper has jammed when a printer begins to print a document?

Answer 27

- The printer generates an interrupt. The interrupt is given a priority and queued. - The interrupt stops the CPU from processing the current task. - The Interrupt Service Routine (ISR) services an interrupt, generating an output message to state that there is a paper jam.