Writing an exam answer about software and interrupts

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which answer to 'State one difference between system and application software' earns the mark?

A System software manages the computer (e.g. an operating system), but application software lets the user do a task (e.g. a word processor).

B System software is the important software, but application software is the less important software.

2. Which is the better way to describe an OS function in an exam?

A The OS does memory.

B The OS manages memory by deciding where each program is stored in RAM, so programs do not overwrite each other.

3. The question asks you to describe the layers of a computer from the user's side. Which answer gives them in the correct order?

A Hardware, then applications, then firmware, then operating system.

B Applications, then operating system, then firmware, then hardware.

4. Which statement uses the correct term for what an interrupt is?

A An interrupt is a signal sent to the CPU asking it to stop its current task and deal with an event.

B An interrupt is a crash that happens when the computer breaks.

5. Which answer correctly describes the first steps of interrupt handling?

A The interrupt is generated, the CPU finishes the cycle and checks for it, then saves its state and runs the ISR.

B The CPU runs the ISR, then the interrupt is generated, then the CPU saves its state.

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1State the point, then add 'because...'		AApplications > Operating system > Firmware > Hardware
21. Save state 2. Run ISR 3. Restore state		BAn interrupt is not a crash. It is a signal to the CPU that something needs attention, and the CPU runs an ISR and then carries on.
3Use the correct term for software that manages the computer, with an example and a reason		CThe OS is system software because it manages hardware and files.
4Describe the layers in the correct order from the user down to the hardware		DFirmware is not an application. It is permanent software stored in ROM that starts up and controls the hardware, such as the bootloader.
5An interrupt is when the computer crashes.		EA full-mark structure: give one correct point and follow it with a reason that explains why it is true
6Firmware is an application the user installs.		FDescribing interrupt handling in the correct order, using the correct term ISR

Definitions

point and reason

Fill in the Blanks

Complete each line of code by filling in the missing parts.

The OS is _______________ because it manages the hardware.

1. The CPU checks for an interrupt 2. The ___ is run to handle it

Applications > OS > ________ > hardware

The bootloader loads the OS into RAM _______ the OS must be running to use apps.

An interrupt is a signal, not a _____.

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A 1 A signal is sent to the CPU

B 2 CPU saves its registers

C 3 CPU runs the application

D 4 CPU restores its registers

E 5 CPU resumes the old task

Question 2

A Application software: the OS

B It manages the hardware

C Reason: apps need it to run

Question 3

A Layer 1: applications

B Layer 2: operating system

C Layer 3: firmware

D Layer 4: utility software

E Reason: each uses the one below

Question 4

A Firmware is stored in ROM

B It contains the bootloader

C The bootloader loads the OS

D Reason: ROM is volatile

Question 5

A An interrupt is a signal

B It means the computer crashed

C Reason: the CPU must respond

Answer Key

Writing an exam answer about software and interrupts

Section A: Quick Questions

A — System software manages the computer (e.g. an operating system), but application software lets the user do a task (e.g. a word processor).

B — The OS manages memory by deciding where each program is stored in RAM, so programs do not overwrite each other.

B — Applications, then operating system, then firmware, then hardware.

A — An interrupt is a signal sent to the CPU asking it to stop its current task and deal with an event.

A — The interrupt is generated, the CPU finishes the cycle and checks for it, then saves its state and runs the ISR.

Section B: Match the Pairs

State the point, then add 'because...' → A full-mark structure: give one correct point and follow it with a reason that explains why it is true

1. Save state 2. Run ISR 3. Restore state → Describing interrupt handling in the correct order, using the correct term ISR

Use the correct term for software that manages the computer, with an example and a reason → The OS is system software because it manages hardware and files.

Describe the layers in the correct order from the user down to the hardware → Applications > Operating system > Firmware > Hardware

An interrupt is when the computer crashes. → An interrupt is not a crash. It is a signal to the CPU that something needs attention, and the CPU runs an ISR and then carries on.

Firmware is an application the user installs. → Firmware is not an application. It is permanent software stored in ROM that starts up and controls the hardware, such as the bootloader.

Section C: Definitions

point and reason — A full-mark answer uses the correct terms (system software, firmware, bootloader, ISR), gives points in the right order, and adds a reason for each point.

Section D: Fill in the Blanks

The OS is system software
because it manages the hardware.

1. The CPU checks for an interrupt
2. The ISR is run to handle it

Applications > OS > firmware > hardware

The bootloader loads the OS into RAM
because the OS must be running to use apps.

An interrupt is a signal, not a crash.

Section E: Spot the Error

C — After saving its state, the CPU runs the interrupt service routine (ISR), not the application. Line 3 should be '3 CPU runs the ISR'.

A — An operating system is system software, not application software. Line 1 should be 'System software: the OS'.

D — The bottom layer is the hardware. Utility software is system software and sits in the operating system layer. Line 4 should be 'Layer 4: hardware'.

D — ROM is non-volatile, so firmware is kept when the power is off and is available at start-up. Line 4 should say 'non-volatile'.

B — An interrupt is not a crash. It is a signal asking the CPU to deal with an event. Line 2 should be 'It asks the CPU for attention'.