Computer Systems

Question 1

What is hardware?
What is software?

Answer 1

Hardware is the physical components that make up a computer system.
Software are the programs that run on a computer including the operating system.

Question 2

What is system software?

Answer 2

System software programs that are needed for effective communication with the hardware and for launching application software

Question 3

What is application software?

Answer 3

Application software programs launched from the operating system to perform a specific task.

Question 4

What is operating system?

Answer 4

Operating system is a piece of system software that acts as an interface between the user and the hardware managing all hardware and all other software

Question 5

What does the operating system control?

Answer 5

The operating system controls processors, memory, I/O devices, Applications, Security

Question 6

What is utility software?
What does it do?

Answer 6

Utility software are programs that keep the computer functioning efficiently by freeing up storage space, removing viruses, or ensuring files are backed up.

Question 7

What is the CPU?

Answer 7

The central processing unit executes program instructions, performs calculations, and coordinates the behaviour of hardware

Question 8

What are the components of CPU and their functions?

Answer 8

ALU performs various operations

CU manages the execution of instructions by coordinating the hardware

Buses are collections of wires that transmit data between
the computer and computers

Registers a short-term storage for specific pieces of data

Clock regulates the the number of activities that happen within the CPU each second

Question 9

What is main memory?

Answer 9

The main working area of data currently being used and programs currently running.

Question 10

What is RAM?

Answer 10

Random Access Memory is where data and instructions are loaded on to the computer’s hard disk.
It is generally faster, volatile and can run applications concurrently

Question 11

What is ROM?

Answer 11

Read Only Memory. Content cannot be edited or deleted and so is non-volatile and so do not need to be updated. ROM stores bootstrapping instructions which tell the computer the first steps to initialise the computer

Question 12

What is cache memory?

Answer 12

Cache memory stores copies of data or instructions from RAM that are accessed very regularly meaning they can be accessed very quickly.

Question 13

What defines the CPU’s performance?

Answer 13

Number of cores
Clock Speed
Size of Cache
Type of Cache

Question 14

What are cores?

Answer 14

Single units comprising of the ALU and CU which can execute instructions. More cores means more instructions can be performed per second.

Question 15

Describe the Fetch-Execute Cycle?

Answer 15

One of the registers contains the locations where the next instruction is found called the ‘PC’
PC copied to MAR
When an instruction is being transmitted, it is stored in a register called the ‘MDR’ then transferred to ‘CIR’
The instruction is read by the CU which prepares the registers for data to be stored
Then instruction is carried out by retrieving data, performing an operation in the ALU and storing in the memory

Question 16

What is the secondary storage?

Answer 16

Secondary storage is long-term storage from optical, magnetic and solid state storage. They run out of storage space and are non-volatile.

Question 17

What is optical storage?

Answer 17

Optical storage media includes CDs, DVDs, and Blu-Ray disks are written to and read from using lasers.
The surface of these disks have billions of holes can be physically burned by a laser representing either 0 or a 1 with a land or pit.

Question 18

Evaluation of Optical Storage

Answer 18

Advantages:
One optical disk is very cheap, often read-only, so difficult to accidentally overwrite data

Disadvantages:
An unprotected disk is vulnerable to being scratched, low data capacity

Question 19

What is magnetic storage?

Answer 19

Magnetic disks are round and the surface of the disk is divided into tracks and sectors. The 3 tracks are circular and divided into 8 segments and are modified by a read-write head. Magnetic particles exists that are magnetised (1) or unmagnetised (0)

Question 20

Evaluation of Magnetic Storage

Answer 20

Advantages:
Cheapest storage medium per MB, Less effort than multiple optical disks

Disadvantages:
Slower access speeds, Data is all on one device which can be lost

Question 21

What is solid state?

Answer 21

Solid state storage devices use electronic circuits and no moving parts to store data electronically. Using electrical circuits mean they retain data without a power supply

Question 22

Evaluation of Solid State

Answer 22

Advantages:
Faster access speeds than both optical and magnetic, Robust

Disadvantages:
Most expensive form of storage per MB, Limited number of times each bit can be written to

Question 23

What is cloud storage?

Answer 23

This involves storage on remote computers usually managed by other organisations. When a file is modified, it is transmitted across the internet and multiple backups of files often exist around the world.
Uses magnetic and solid state storage.

Question 24

Evaluation of Cloud Storage

Answer 24

Advantages:
With data stored remotely, it is less likely to be misplaced, Capacity on local machine is freed up giving more storage

Disadvantage:
Cloud storage comes with subscription fee, Speed of access is limited by internet connection

Question 25

What are embedded systems?

Answer 25

A computer that exists within a larger mechanical or electrical device

Question 26

What is a computer system?

Answer 26

A set of integrated devices that input, output, process, and store data and information