Computer Systems

Question 1

What is application software?

Answer 1

Helps a user perform a task

Question 2

What is system software?

Answer 2

Maintains the computer

Question 3

What is generic software?

Answer 3

Software that isn’t made for a specific reason. Created for anyone and obtained for anyone

Question 4

What is integrated software?

Answer 4

A group of similar types of software with similar properties

Question 5

What is specific software?

Answer 5

Software that is made for a specific purpose and to help people.

Question 6

What is bespoke software?

Answer 6

Software made for one person only or company. Made to improve a company.

Question 7

What are logic gates?

Answer 7

Logic gates are the building blocks of digital circuits. Logic gates have one or two inputs that can be turned on or off, the output from the gate will vary depending on the type of logic gate

Question 8

Define the OS

Answer 8

An operating system (OS) is a suite of programs that controls computer hardware and software resources.

Question 9

Name some functions of the OS and explain what they do?

Answer 9

interface - provides a user interface so it is easy to interact with the computer
manages the CPU - runs applications and executes and cancels processes
multi-tasks - allows multiple applications to run at the same time
manages memory - transfers programs into and out of memory, allocates free space between programs, and keeps track of memory usage
manages peripherals - opens, closes and writes to peripheral devices such as storage attached to the computer
organises - creates a file system to organise files and directories
security - provides security through user accounts and passwords
utilities - provides tools for managing and organising hardware

Question 10

What is the NOT gate rule?

Answer 10

The output is the opposite to the input. 1 becomes 0, 0 becomes 1.

Question 11

What is the AND gate rule?

Answer 11

Both of the inputs have to be 1 in order for the output to be 1.

Question 12

What is the OR gate rule?

Answer 12

At least one of the inputs has to be 1 for an output to be 1.

Question 13

What factors effect the performance of the CPU?

Answer 13

Clock speed, cache size, number of processor cores.

Question 14

What is cloud storage?

Answer 14

Cloud storage is stashing data on hardware in a remote physical location, which can be accessed from any device through the internet.

Question 15

What are peripherals? Give an example.

Answer 15

Peripherals are external devices that provides inputs and outputs for the computer. Eg, Webcam.

Question 16

Give some pros and cons to solid state storage and briefly explain how it works.

Answer 16

A solid-state storage device that uses integrated circuits as memory to store data. SSD uses microscopic electronic switches to store data. They have millions of transistors.

Cons

• More vulnerable to abrupt power loss and electromagnetic fields.
• Expensive

Pros

• They are fast as they have no moving parts. It transfers data very quickly.
• Very compact in comparison to other devices so its portable.
• Can store 100mb to 20GB of data.

Question 17

Name some pros and cons to magnetic storage and briefly explain how it works.

Answer 17

A type of storage that is magnetised and uses platters. While the platters are spinning they will be read by a read/write head.

Pros

• Can store up to 1TB of data.
• It has a fast access and retrieval time compared to other devices.

Cons

• It’s usually inside the computer system and isn’t portable.
• Around £2 per GB / expensive

Question 18

Name some pros and cons of optical storage and briefly explain how it works.

Answer 18

There are pits and lands which represent binary code. They are read from the disk using a laser.

Advantages

• Relatively cheap.
• It is fairly portable due to its size.
• Can store between 800MB and 50GB

Disadvantages

• This is slower than most other storage devices.
• Optical media is more durable than tape, HDDs and flash drives and less vulnerable to environmental conditions.

Question 19

Explain the fetch-decode-execute cycle

Answer 19

• The processor checks the program counter to see which instruction will run next.
• Then the program counter gives an address value in the memory of where the next instruction is.
• The processor then fetches the instruction value from this memory location.
• Once fetched the instruction needs to be decoded and executed.
• Once complete the processor goes back to the program counter to find the next instruction.
• The cycle is repeated until the program ends.

Question 20

Name the registers and their purpose

Answer 20

MAR (Memory Address Register) - holds memory location of data that is accessed

MDR (Memory Data Register) - holds data transferred

CIR (Current Instruction Register) - contains current instruction

Question 21

What is the ALU?

Answer 21

Arithmetic Logic Unit - allows operations to be carried out

Question 22

Name the buses and their uses

Answer 22

Address Bus - carries addresses of data

Data Bus - carries data everywhere

Control Bus - carries control signals and commands to CPU

Question 23

Explain the fetch-decode-execute cycle

Answer 23

• The processor checks the program counter to see which instruction to run next.
• The program counter gives an address value in the memory of where the next instruction is.
• The processor fetches the instruction value from this memory location.
• Once the instruction has been fetched, it needs to be decoded and executed.
• Once this is complete, the processor goes back to the program counter to find the next instruction.
• This cycle is repeated until the program ends.

Question 24

What is an embedded system?

Answer 24

A computer system that is designed for a specific function.

eg. cars, mobile phones

Question 25

Pros and cons to cloud storage

Answer 25

Pros

• only pay for storage you use
• automatically backed up
• data available anywhere

Cons

• reliable network connection
• software will need to be its latest version
• dependant on speed of internet