About Hardware and software in O Level Computer Science
Hardware and software is one of the 4 main topics in our O Level Computer Science (Cambridge (CAIE) 2210) question bank, and about 20% of its real questions come from it. Tayyari Karo has 39 real questions on this topic from 2021 to 2026, from Paper 1, Paper 2. By difficulty: 25 medium, 14 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
Try 8 real questions
These are real past-paper questions. Think of your answer first, then open the explanation.
May/June 2024 · Paper 1 · Hardware and software
A computer needs firmware and system software to operate. (a) State the purpose of firmware. (b) Give one example of firmware. (c) Give two examples of system software.
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(a) Firmware is permanent software stored in ROM/EEPROM that controls the hardware at a low level and starts the computer (e.g. it contains the instructions needed to boot the system).
(b) Any one: BIOS, UEFI, bootloader.
(c) Any two: operating system, device drivers, utility software.
Firmware = low-level permanent software (BIOS); system software = OS, drivers, utilities.
Oct/Nov 2024 · Paper 1 · Hardware and software
7 A computer has an operating system.
(a)(i) Tick one box to show which is not a function of the operating system: managing files, providing an interface, handling interrupts, loading the bootstrap. (ii) Identify one other function of an operating system and describe its purpose.
(b) Give the name of the set of instructions provided to the operating system to allow it to run.
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7 (a)(i) loading the bootstrap (this is done by firmware/ROM).
(a)(ii) e.g. memory management - allocates RAM to programs and frees it when finished; or processor scheduling - decides which program uses the CPU and when; or security - controls access to resources.
(b) Device drivers (or drivers).
May/June 2023 · Paper 1 · Hardware and software
A farm has an automated drinking system for its animals. The drinking system has a water bowl that contains the water. When the water bowl is empty, it is automatically refilled. The system uses a sensor and a microprocessor. (a) Identify the most appropriate sensor for this system. (b) Describe how the sensor and the microprocessor are used to automatically refill the water bowl.
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(a) A water-level sensor / float switch (or pressure sensor).
(b) The sensor measures the water level in the bowl and sends this data to the microprocessor. When the level falls to empty (below a threshold), the microprocessor sends a signal to open a valve/pump to refill the bowl. When the sensor detects the bowl is full, the microprocessor closes the valve/pump. This repeats as a control loop.
Float/water-level sensor triggers microprocessor to open valve when empty.
May/June 2023 · Paper 1 · Hardware and software
A company uses robots in its factory to manufacture large pieces of furniture. (a) One characteristic of a robot is that it is programmable. State two other characteristics of a robot. (b) Give two advantages to company employees of using robots to manufacture large pieces of furniture. (c) Give one disadvantage to the company's owners of using robots to manufacture large pieces of furniture.
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(a) Any two: a robot can sense its environment (has sensors); a robot can act on/move its environment (has actuators/motors); a robot can operate automatically/autonomously; a robot can make decisions.
(b) Any two: safer (robots do dangerous/heavy work); less physically tiring; higher productivity; more consistent quality.
(c) Any one: high initial purchase cost; job losses for employees; maintenance/repair costs.
Robots: programmable, sense, actuate, autonomous. Pros: safety/productivity. Cons: cost/jobs.
Oct/Nov 2023 · Paper 1 · Hardware and software
8 Storage can be magnetic, solid-state or optical.
(a) Give two features of magnetic storage.
(b) Give three features of solid-state storage.
(c) Give one example of each type of storage.
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8 (a) Two features of magnetic: uses spinning magnetic platters and read/write heads; high capacity; low cost per GB; slower than SSD; non-volatile; susceptible to mechanical failure. (Any two.)
(b) Three features of solid-state: no moving parts; faster access; more reliable/durable; uses flash memory; lower power use; smaller/lighter; more expensive per GB. (Any three.)
(c) Magnetic: hard disk drive (HDD). Solid-state: SSD / memory stick / flash drive. Optical: CD / DVD / Blu-ray disc.
Oct/Nov 2023 · Paper 1 · Hardware and software
9 An interrupt is a type of signal used in a computer.
(a) State the name of the type of software that manages interrupts.
(b) Describe how interrupts are used when a key is pressed on a keyboard.
(c)(i) Give two other examples of a hardware interrupt. (ii) Give two examples of a software interrupt.
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9 (a) Operating system.
(b) Pressing a key sends an interrupt signal to the CPU; the CPU finishes its current instruction, saves its state, and runs an interrupt service routine (ISR) that reads the key's code from the buffer and processes it, then returns to the previous task.
(c)(i) Hardware interrupts: printer out of paper; mouse movement; disk drive ready; timer; power button. (ii) Software interrupts: division by zero; invalid instruction; operating system service call (system call); program error/exception.
May/June 2022 · Paper 1 · Hardware and software
A compiler and an interpreter are two different types of translator. (a) One similarity between a compiler and an interpreter is that they both translate high-level language into machine code. (i) Give one other similarity between a compiler and an interpreter. (ii) Explain two differences between a compiler and an interpreter.
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(a)(i) Other similarity: both produce error messages for syntax errors; both are needed to run a high-level program; both produce low-level code.
(a)(ii) Difference 1: a compiler translates the whole program at once and produces a separate executable file (the program can then run without the compiler), whereas an interpreter translates and executes one line/statement at a time (the interpreter is needed each time the program runs). Difference 2: with a compiler, errors are listed after the whole program is checked (so execution only happens once all errors are fixed); with an interpreter, errors are found and reported as each line is executed (easier to debug but slower to run).
Compiler: whole program -> executable, faster run. Interpreter: line-by-line, easier debugging, slower.
Oct/Nov 2021 · Paper 1 · Hardware and software
7 (a) Tick one box to identify if an internal Solid State Drive (SSD) is an example of primary, secondary or off-line storage. Justify your choice.
(b) Describe the operation of an SSD and how it stores data.
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7 (a) Secondary storage. Justification: an SSD is non-volatile, used for long-term storage of programs and data; it is not directly accessed by the CPU (primary storage is RAM), and it remains part of the computer system (not off-line, which is removable media such as a memory stick or optical disc).
(b) An SSD uses flash memory (NAND) with no moving parts. Data is stored as electrical charges in memory cells; a controller manages reading and writing. Data persists when power is removed. It is faster and more durable than a magnetic hard disk.
