Chapter 4 - Operating systems and computer architecture Flashcards Preview

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Flashcards in Chapter 4 - Operating systems and computer architecture Deck (24)
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1

Define Operating System

the software running in the background of a computer system - it manages many of the basic functions

2

What is an interrupt?

a signal sent from a device (or other software) to the processor requesting its attention

3

What is a buffer?

a temporary memory area in a device

4

Define computer architecture

how a computer system is designed

5

What do buses do?

buses move data around the computer and also send out control signals to synchronise the internal operations

6

What are registers?

high-speed storage areas within the computer

7

What is a memory unit made up of?

it is made up of addresses and contents

8

What is a control unit?

it controls the operation of the memory, processor and input/output devices

9

Give 5 examples of operations/tasks Operating Systems do

human-computer interface (HCI)
multitasking
multiprogramming
batch processing
error handling
load/run applications
management of user accounts
file utilities
processor management
memory management
real-time processing
interrupt handling
security
input/output control

10

What are examples of devices that do not require an operating system?

ovens
washing machines

11

Why do some devices not need an operating system?

they carry out simple, unchanging tasks which are initiated by a user pressing a button

12

What do interrupts cause the processor to do?

temporarily stop what it is doing and service the interrupt

13

Why are buffers used?

to compensate for the slower operating speed of peripherals when compared to a processor

14

What do buffers allow processors to do?

to carry on with other tasks

15

What is an example where buffers are used?

printers
music/video streaming

16

What is the von neumann architecture?

a concept that holds programs and data in memory
data moves between the memory unit and processor
between processor, memory unit and input/output devices

17

What does an address bus do?

carries signals relating to addresses between the processor and memory
uni-directional

18

What does a data bus do?

sends data between the processor, memory unit and the input/output devices
bi-directional

19

What does a control bus do?

carries signals relating to control and coordination of all activities within the computer, it can be uni-directional or bi-directional due to internal connections

20

Where must data be represented before it is processed?

in registers

21

What are 5 different types of registers in the von neumann architecture?

Memory address register (MAR)
Memory data register (MDR)
Arithmetic and Logic Unit (ALU)
Program counter (PC)
Current Instruction Register (CIR)

22

What does a control unit do?

read instructions
interprets instructions
sends out signals along control bus to synchronise all computer components

23

What does the fetch part of the fetch execute cycle entail?

the next instructions are fetched from the memory address stored in the PC
this is then stored in the CIR
the PC is incremented by so the next instruction can be processed

24

What does the execute part of the fetch execute cycle entail?

the decoded instruction is then passed as a set of control signals to the appropriate components of the computer system