Computer systems

Question 1

Define hardware

Answer 1

Physical component that makes up the computer.

Question 2

Define software

Answer 2

Any program that runs on the computer.

Question 3

What is system software?

Answer 3

Programs that are needed to enable the computer to function, including the operating system, utilities, library routines and programming language translators.

Question 4

What is application software?

Answer 4

Programs that enable a user to perform a task.

Question 5

What is managed in an operating system software?

Answer 5

• processors
• memory
• input/output devices
• applications
• security

Question 6

What does processor management do?

Answer 6

Manages the use of the processor resources.

Question 7

What does memory management do?

Answer 7

When a program is running it mut be in the computer’s main memory, and the OS must manage where in memory each program and data needs to go.

Question 8

Give examples of input devices?

Answer 8

• a mouse
• a keyboard
• microphone
• sensor

Question 9

Examples of output devices?

Answer 9

• speaker
• conventional computer screen
• an actuator

Question 10

What does application management do?

Answer 10

When applications are installed an operating system will run a program to install it.

The OS will interact with applications through an Applications Program Interface (API).

Question 11

What are methods in security management?

Answer 11

• passwords and different users
• Setting different access rights and privileges for different users
• Automatically downloading updates for the OS to ensure security loopholes are patched
• Encrypting files

Question 12

What is in the Von Neumann architecture?

Answer 12

• the program is stored in main memory and instructions are fetched and executed sequentially
• there is a single memory (and bus system) for accessing both data and programmes

Question 13

Function of ALU?

Answer 13

Arithmetic Logic Unit
- Logical Operations : boolean (AND, OR…)
- Shift operations: binary shift
- Arithmetic operations: addition, subtraction, multiplication, division

Question 14

Function of Control Unit?

Answer 14

• controls execution of instructions in the same sequence
• decodes instructions
• regulates and controls processor timing using system clock
• sends and receives control signals to and from other devices within the computer

Question 15

Function of clock?

Answer 15

Controls processor timing

Question 16

Function of Bus?

Answer 16

Pass data between the components of the CPU.

Question 17

Function of system bus?

Answer 17

Program instructions and data move between main memory and processor using internal connections called buses.

Question 18

Describe the fetch-execute cycle

Answer 18

Fetch :
- address A of the next instruction is fetched from the register (a special fast memory location in the processor) where it is held

• This register is incremented so it points to the next instruction to be fetched
• Instruction at Address A is fetched from memory and put into a special register ready to be decodes

Decode:
- CU decodes the instruction to see what has to be done next

Execute:
- Instruction is execute