computer systems

Question 1

what is an embedded system? give examples

Answer 1

A system designed to perform a single specific function,e.g Washing machine, microwave, printer.

Question 2

what are the parts of the CPU?

Answer 2

1. the CU - manages FDE cycle
2. the ALU - does all calculations and stores it
3. the cache - stores regularly used data

Question 3

what happens in Fetch?

Answer 3

memory address is copied from the PC to the MAR
MAR copies instructions to MDR
the PC increments by one

Question 4

what happens in execute?

Answer 4

Instructions are performed in the ALU and stored in the ACC

Question 5

what happens in decode ?

Answer 5

instructions in the MDR is decoded by CU which then loads values into MAR

Question 6

what does the cpu performance depend on ?

Answer 6

Clock speed - num of instructions carried out per sec, increasing clock speed means more instructions carried out per sec
Cashe size - cashe is faster than ram, more cashe means faster access to more data
Num of cores - cores process instructions independently, more cores means more instructions can be carried out at once

Question 7

What is the difference between RAM and ROM ?

Answer 7

RAM - volatile, can be read and written to, slower than cashe
ROM - non-volatile, is read only, stores boot up instructions(BIOS)

Question 8

name the data measuring units in order

Answer 8

BIT (1 or 0)
NIBBLE (4 bits)
BYTE (8 bits)
KB (1000 byte)
MB (1000 KB)
GB (1000 MB)
TB (1000 GB)
PB (1000 TB)

Question 9

What unit stores files like; songs, pictures and documents

Answer 9

KILOBYTE

Question 10

What unit stores videos and complex applications?

Answer 10

GIGABYTES

Question 11

what base is denary

Answer 11

base 10

Question 12

what base is binary

Answer 12

base 2

Question 13

what error occurs when there is too much bits

Answer 13

overflow error

Question 14

what does a left shift do to the number

Answer 14

multiplys by 2

Question 15

what is LAN

Answer 15

covers a small geographical area located on a single site

Question 16

ADV of LAN

Answer 16

1. easier to share files
2. user account is stored centrally so user can use any device on the network

Question 17

what is a DNS

Answer 17

1. when a client requests a url via web browser
2. browser sends domain name to domain name server
3. The DNS maps the domain name to the ip address and returns it to the browser.

Question 18

what isa protocool

Answer 18

a set of rule that allow 2 devices to communicate

Question 19

what is a network

Answer 19

a set of agreed requirements for hardware and software

Question 20

what is HTTP used for

Answer 20

used by web browsers to communincate with web servers

Question 21

what is HTTPS used for

Answer 21

a secure version of http that encrypts all information sent and recieved

Question 22

what is FTP used for

Answer 22

used to access, edit and move files between devices on a network

Question 23

what is POP uses for

Answer 23

used to retrieve emails from a server

Question 24

what is logical error

Answer 24

when programm runs but does not give expected out put because the input it wrong

Question 25

what does the cu do in the f-d-e cycle

Answer 25

decodes instructions and coordinates the cycle

Question 26

what is the role of a program counter PC

Answer 26

it hold memory address of next instruction to be fetched

Question 27

what does cashe store

Answer 27

frequently used instructions and data

Question 28

Name the functions of the 3 OS

Answer 28

1. provides user interface to allow user to interact with computer 2. Deals with file management and disk management 3. communicated with internal and external hardware via device drivers

Question 29

what are the 4 user interface?

Answer 29

Graphical user interface Command line interface Natural language interface Menu driven interface

Question 30

What are the qualities of Graphical user interface GUI?

Answer 30

It uses WIMP it is easy to use

Question 31

What are the qualities of Command line interface CLI

Answer 31

it is difficult to use it requires less processing power

Question 32

What are the qualities of Natural language interface?

Answer 32

it requires users voice to interact it is instritive but limited

Question 33

What are the qualities of Menu driven interface?

Answer 33

a series of limited menus are shown to the user

Question 34

What is multitasking? (Memory management)

Answer 34

when the OS allows multiple programs to be open and running at once

Question 35

what is the causes fragmentation?

Answer 35

1. files are stored on available spaces on a hard disk 2. when files are moved, deleted, created or renamed gaps starts to appear on the disk 3. the OS splits the files up into smaller blocks to fill the gaps 4. causing it to become more and more fragmented over time

Question 36

what does defragmentation do?

Answer 36

defragmentation contigiously reorganises files on hard disk and puts fragments of files back together to collect space together and store all file consecutively

Question 37

what does utility software do?

Answer 37

1. helps maintain and configure the computer 2. extra utility can be installed to perform more tasks.

Question 38

how does the OS allow for user management?

Answer 38

- OS allows for multiple accounts on one device - Each user has their own settings, programs and files which is unaccessible to other users.

Question 39

what is a peripheral?

Answer 39

hardware that connects to the computer and allows special functions e.g printer, keyboard

Question 40

What is a device driver

Answer 40

software used to communicate with peripherals connected to the computer

Question 41

what does encryption do?

Answer 41

scrambles data to prevent third parties / hacker from being able to read it. A private key is needed to decrypt it

Question 42

what is the definition and types of data compression

Answer 42

compression is reducing file size to allow for more file to be stored and downloaded faster. LOSSY - permanently deleting data that won't be noticed, but the file can't restore its original quality LOSSELESS - using an algorithim to compress a file and file can be restored to its original quality.

Question 43

How does the OS allows for File management?

Answer 43

The OS organises files into a manageable hierarchy structure that allows users to create, delete, rename and move.

Question 44

what is defragmentation faster?

Answer 44

when fragmented files are put together it reduces the read/write head going back and forth looking for files because it is organised so its quicker to find