computing | gcse | ocr - langdon park school - home · ocr gcse computing learning grids – h/w...

This learning grid H/W belongs to: Name: ______________________________ Form: _______________________________

OCR GCSE Computing Learning Grids – H/W Unit A451: Computer Systems and Programming

COMPUTING | GCSE | OCR | J275

Mr. Ahmed

A451 - ATTENTION! Please read!

1. These learning grids cover the key theory content of the

OCR GCSE Computing specification. Learn them and you

will pass the exam!

2. The grids closely follow the content and order of unit A451: Computer Systems and Programming.

• Complete each section for homework once they are

covered in your lessons!

• All sections must be fully completed!

• Once you have completed a section hand it in to your

teacher.

To help you find the information you need, the grids contain

page references to the corresponding sections of GCSE

computing book:

OCR Computing for GCSE published by Hodder Education

(ISBN: 978-14441-7779-4).

HODDER

OCR GCSE Computing Learning Grids Page 1 of 28

Contents

Blank Grids ............................................................................................. Error! Bookmark not defined.

2.1.1 Fundamentals of Computer Systems ............................................................... 2

2.1.2 Computing Hardware ................................................................................. 4

2.1.3 Software ................................................................................................ 9

2.1.4 Representation of Data in Computer Systems ................................................... 11

2.1.5 Databases ............................................................................................ 17

2.1.6 Computer Communications and Networking .................................................... 20

2.1.7 Programming ........................................................................................ 26

Talk to Us!

Love it as it is?

Let the author and other teachers know what you think

Got a suggestion? If your improvement leads to an update we will

send you a new copy for free

Found a problem? We will fix it and send you a

free updated copy

L


HODDER: 7-16 2.1.1 FUNDAMENTALS OF COMPUTER SYSTEMS

2.1.1 Fund ament als of Comput er Syst ems

COMPUTER

SYSTEMS

What is a computer system?

What is the name for the

interconnections between systems?

What are the three main stages in any

system? 1. 2. 3.

What is a system boundary? Why can

they be difficult to define?

What is the difference between general-

purpose and dedicated systems?

Give an example of each.

Difference:

Examples:

What is an embedded system?

Explain what is meant by the kernel in

operating systems.

Why is reliability important in computer

systems? Give an example of a situation

in which reliability is essential.

2.1.1 Fundamentals of Computer Systems


COMPUTER

SYSTEMS

(CONTINUED)

How can the reliability of a system be

assessed?

Why is it useful to develop systems to

standards?

Explain the difference between

proprietary and open standards.

What name is given to a standard which

develops simply through common usage?

Give an example of a computing industry

standard.

What is meant by ethics in regard to

computer use?

How has the Internet affected people's

right to privacy?

Describe two ways in which the use and

disposal of computer systems can have a

negative effect on the environment.

1.

2.

State two UK legal acts relating to

computer use, and explain the purpose

of each.

1.

2.

L


HODDER: 18-45 2.1.2 COMPUTING HARDWARE

2.1.2 Co mputing H ardware

CENTRAL

PROCESSING

UNIT (CPU)

HODDER: 19-23

What is the purpose of the CPU?

What are the two main components of

the CPU? 1. 2.

What cycle does the CPU carry out

continuously to process instructions?

What is meant by clock speed?

What component controls the clock

speed?

Who is credited with the idea of storing

data and programs in the same place in

the computer architecture?

What is a dual-core CPU?

In computing, what is a bus?

MEMORY

HODDER: 25-30

What does the ROM usually store?

What is virtual memory, and why is it

used?

What is a disadvantage of having to use

virtual memory?

2.1.2 Computing Hardware


MEMORY

(CONTINUED)

What is flash memory?

Using an example for each, explain the

difference between primary and

secondary storage.

What is the purpose of cache memory?

What it the purpose of RAM?

How could the addition of extra RAM

speed up a computer? Why might this

not always be effective?

BINARY LOGIC

HODDER: 31-35

ZIGZAG: 13-15

Why do computers operate in binary?

What is a logic gate?

Name three types of logic gate.

What are truth tables used for?

What logic gate does this symbol

represent?



BINARY LOGIC

(CONTINUED)


represent?


represent?

Draw a truth table for the following

circuit.

A B R=A OR B P

What name is given to the branch of

algebra used in logic circuits?

INPUT AND

OUTPUT

DEVICES

HODDER: 36-41

Name three input devices. 1. 2. 3.

Name three output devices. 1. 2. 3.

Give an example of a device which has

both input and output functionality.

State a common application of the

device given in the previous question.



INPUT AND

OUTPUT

DEVICES

(CONTINUED)

State and describe a suitable input device

for a user with a visual impairment. Device:

Description:

State and describe a suitable input device

for a user with severely limited physical

mobility.

Device:

Description:

What is a sensor?

What is an actuator?

Name two input devices typically found

on a smartphone. 1. 2.

Name two output devices typically found

on a smartphone. 1. 2.

State and describe a suitable output

device for a user with a visual

impairment.

Device:

Description:

State and describe a suitable output

device for a user who is unable to

communicate verbally.

Device:

Description:

State three applications of RFID tags. 1.

2.

3.

Describe two types of printer and

suggest what applications they might

have.

1.

2.



SECONDARY

STORAGE

HODDER: 42-45

Why is secondary storage necessary?

Name the three main categories of

secondary storage device. 1. 2. 3.

State three common secondary storage

devices and describe a purpose for

which each might be used.

1.

2.

3.

Briefly describe how data is physically

written to a hard-disk.

Briefly describe how data is physically

written to a CD or DVD.

Name the five factors that are necessary

to consider when choosing an

appropriate secondary storage device.

1. 2. 3. 4. 5.

What is the most common secondary

storage device used as the main storage

for desktops and laptops?

L


HODDER: 47-67 2.1.3 SOFTWARE

2.1.3 Software

SOFTWARE

HODDER: 47-67

Define the term ‘software’.

What is a user interface?

Describe two different types of user

interface that could be used to operate

a computer.

1.

2.

Explain the difference between system

software and application software.

How can an operating system

multitask?

What is meant by memory and

peripheral management?

Give three examples of common

security features in operating systems. 1. 2. 3.

What is meant by utility software?

2.1.3 Software


SOFTWARE

(CONTINUED)

Name and describe two types of disk

organisation utility. 1.

2.

Name and describe two types of

system maintenance utility. 1.

2.

Name and describe two types of

security utility. 1.

2.

Explain the difference between custom-

written and off-the-shelf software.

Describe one advantage to a business of

using custom-written software.

Describe one disadvantage to a

business of using custom-written

software.


proprietary and open-source software.

Describe one advantage of using

open-source software.

Describe one disadvantage of using

open-source software.

L


HODDER: 69-88 2.1.4 REPRESENTATION OF DATA IN COMPUTER SYSTEMS 2.1.4 Represent ation of Dat a in Computer Syst ems

UNITS

HODDER: 70

What name is given for the number

system in base 10 that humans use?

What name is given to the number

system in base 2 that computers must use to store and process data?

Why must all data be converted into

this form before it can be processed by the computer?

Fill in the gaps in the sequence to

order the binary units from smallest

(top) to largest (bottom).

bit

byte

kilobyte

gigabyte

How many bits are there in a byte?

How many bytes are there in a kilobyte?

How many bits are there in a kilobyte?

What name is given to the unit made

up of approximately a billion bytes?

What name is given to the unit made

up of 1,024 gigabytes?

Consider a five-digit binary number.

What is the highest number that can be stored?

2.1.4 Representation of Data in Computer Systems


NUMBERS

HODDER: 70-76

Convert these binary numbers into denary.

010 10101

1110 0011

Convert these denary numbers into

binary. 34

53

Convert these hexadecimal numbers

into denary. 37

C4

Convert these hexadecimal numbers

into binary.

Hint: convert each hex digit into four binary digits and concatenate.

41

5D

Why is hexadecimal number

representation often used in computing?

Add these two binary numbers

together. 101 1101 + 001 1010

Explain a problem that can arise when

adding two 8-bit binary integers to get an 8-bit answer.



CHARACTERS

HODDER: 78-79

How are individual characters

represented by a computer?

What is meant by the term ‘character

set’?

What does ASCII stand for?

How many different characters can the

ASCII set represent?

How many bits does this use per

character?

Explain the limitations of using ASCII

for global communication.

Suggest a different character set that

would be more useful for global

communication.

How many bits does this character set

use per character?

Explain one possible disadvantage to

using this character set instead of

ASCII.

Do you think that this is a significant

problem or not?



IMAGES

HODDER: 80-83

What is a pixel?

Describe how a simple black and white

bitmap image can be stored by the

computer.

The binary numbers below represent a

simple black and white bitmap image.

On the 8 × 8 grid, fill in the

appropriate spaces to create the image.

A 1 represents black and a 0

represents white. Fill in each 8-bit

string of digits in regular reading order.

1111 1111 1000 0001

1000 0001 1000 0001

1000 0001 1111 1111

0001 1000 0111 1110

How is the storage of a colour images

different from that of black and white

images?

What is colour depth?

What is metadata?

What information might typically be

stored in image metadata?



IMAGES

(CONTINUED)

What is resolution?

What are the effects of colour depth

and resolution on the file size of the

image?

How do vector graphics differ from

bitmap images?

What is a possible advantage of using

vector graphics instead of bitmaps?

SOUND

HODDER: 84-86


analogue and digital signals.

Describe the process of converting an

analogue sound signal to digital.

What is meant by the ‘sample rate’ of

an audio recording?

What effect does the bit rate have on

the audio quality?

What effect do the bit rate and sample

rate have on the file size of the

recording?



INSTRUCTIONS

HODDER: 87-88

Explain how the CPU distinguishes

between instructions and data.

What are the two parts of each

program instruction called? 1. 2.

What are registers?

What is the name of the register which

keeps the address of the next

instruction to be processed?

What is the name of the register that

stores data currently in use?

What is an address?

L


HODDER: 90-110 2.1.5 DATABASES

2.1.5 D atabases

THE DATABASE

CONCEPT

HODDER: 90-96

Define ‘database’.

Explain the difference between a serial

file and a sequential file.

What is an indexed sequential file?

What is a flat file database made up of?

How many tables does a flat file

database have?

What is meant by data redundancy?

Why is this undesirable?

Explain the difference between data

validation and data verification.

State three types of data validation

check. 1. 2. 3.

DATA MODELS

HODDER: 96-98

What is a relational database?

State two other database models. 1. 2.

What name is given to a subject about

which data is stored?

What is a meant by a ‘one-to-many’

relationship?

2.1.5 Databases


DATA MODELS

(CONTINUED)

Draw a diagram which represents a

one-to-many relationship, using an

example of your choice.

What are attributes?

How are attributes stored in a data

table?

What are records?

How are records stored in a data

table?

DATABASE

DESIGN

HODDER: 98-100

What a schema?

What data structure stores schemata?

What are primary keys used for?

What quality must primary keys have

to make them useful?

What is meant by ‘mission critical’

databases?

State four decisions which must be

made about each field in the database. 1. 2. 3. 4.

What is a foreign key?

2.1.5 Databases


DATABASE

MANAGEMENT

SYSTEMS (DBMS)

HODDER: 100-109

What is a DBMS?

What is the purpose of using a DBMS?

Give three examples of ways in which

the DBMS enables protection and

security.

1. 2. 3.

Name and describe three different ways

in which a database can be viewed. 1.

2.

3.

How does the DBMS deal with

concurrency problems?

What does the acronym ACID stand for? A: C: I: D:

What is the purpose of ACID?

What is a query and what are they used

for?

What does SQL stand for?

Explain what is meant by the term ‘data

mining’.

Suggest one reason why many high-

street chains of shops issue electronic

loyalty/reward cards to customers.

L


HODDER: 112-147 2.1.6 COMPUTER COMMUNICATIONS AND NETWORKING

2.1.6 Co mputer Communic ations and Networking

NETWORKS

HODDER: 112-136

What is a network?

Describe three ways in which

computer networks have improved

productivity in the workplace.

1.

2.

3.

Describe two potential issues that can

arise from the use of networks. 1.

2.

What is the function of the network

interface card?

Where can network interface cards

usually be found in the computer?

What device can be used to prevent

signal bouncing in bus networks?

What name is given to the process of

signals losing integrity as they travel

through a network medium?

What device can be used to counter

the above issue? How does it work?

Explain the purpose of a hub.

Why may using several hubs potentially

slow down a network?

What device can be used to connect

different network media and segments?

2.1.6 Computer Communications and Networking


NETWORKS

(CONTINUED)

What is a switch?

Why are switches able to operate at

such high speeds?

Explain the difference between a level

2 and a level 3 switch?

What is the purpose of a router?

Describe the features of a peer-to-

peer network.

Explain the workings of the client–

server network model.

Give two advantages of using client–

server networks over peer-to-peer. 1.

2.

Give two disadvantages of using client–

server networks over peer-to-peer. 1.

2.

Outline the main features of the bus,

ring and star network topologies. Bus:

Ring:

Star:



NETWORKS

(CONTINUED)

Draw a simple diagram to represent

each network topology. Bus:

Ring:

Star:

What do the acronyms LAN and

WAN stand for? LAN: WAN:

Explain the primary difference between

a LAN and a WAN.

What is the function of a metropolitan

area network (MAN)?

What is a VPN?

Describe one reason why an

organisation might use a VPN.

State three mediums for transmitting

data over a network.

For each medium above, state one

potential advantage and disadvantage of

using that medium.

Medium

Advantage

Disadvantage



NETWORKS

(CONTINUED)

What is a protocol?

Name and describe three common

network protocols. 1.

2.

3.

What is a MAC address?

What is an IP address?

Explain how IP addresses can be static

or dynamic.

Describe how the process of packet

switching is used to carry data across a

network.

What is meant by bandwidth?

There are likely to be several network

policies in place on your school

network. Can you identify three of

these?

1.

2.

3.

What is meant by acceptable use?

Explain the difference between back-up

and archiving.

Explain what is meant by a network

disaster recovery policy.



THE INTERNET

HODDER: 138-146

Fundamentally, what is the Internet?

State two of items of hardware that

are required to connect to the

Internet.

1. 2.

Describe, in simple terms, the function

of each of these hardware items.

What is the difference between the

World Wide Web and the Internet?

What is a hyperlink?

Explain the role of DNS servers and

how this relates to IP addresses.

What standard language is used to

write web pages?

Describe two other standards which

can be applied to web pages. 1.

2.

State a common Internet file standard

for images.


for sound files.



THE INTERNET

(CONTINUED)


for storing documents.

What is compression?

Why is it important when sending files

over the Internet?

Explain the difference between lossy

and lossless compression.

Surely lossless compression always a

better choice than lossy compression?

Justify your answer.

Give an example of a type of file for

which lossy compression should not be

used.

L

OCR GCSE Computing Learning Grids Page 26 of 28 © ZigZag Education, 2014

HODDER: 149-183 2.1.7 PROGRAMMING

2.1.7 Programming

ALGORITHMS

HODDER: 150-156

What is an algorithm?

Who is regarded as the first ever

computer programmer?

What was the name of the first ever

general-purpose, high-level

programming language?

State and describe two different ways

in which an algorithm can be

represented.

1.

2.

What shape on a flow chart is used to

represent a selection (decision or

choice)?

What shape on a flow chart is used to

represent an input or output?

What does this flow chart symbol

represent?

What is meant by ‘tracing’ an

algorithm?

2.1.7 Programming


ALGORITHMS

(CONTINUED)

Draw a flow chart for an algorithm to

represent the following situation:

A boy leaves his house in the morning

to travel to school.

He checks the time on his watch

when he sets off. If the time is before

8am, he decides to walk to school.

However, if the time is 8am or later

he decides to take the bus.

He always follows this rule, and either

way he will reach school on time.

Ensure that you use the correct

symbols for each stage of the

algorithm.

Write an equivalent algorithm in

pseudocode for the same process.

2.1.7 Programming


PROGRAMMING

LANGUAGES

HODDER: 156-162

What is machine code?

What is assembly language? How did it

evolve from machine code?

What defines high-level languages?

Describe the function of translator

software.

Describe each of the following

translators: Assembler:

Interpreter:

Compiler:

What is an IDE?

Describe each of the following tools

that might be provided by an IDE. Code editor:

Error diagnostics:

Run-time environment:

Auto-documentation:

2.1.7 Programming


CONTROL FLOW

IN IMPERATIVE

LANGUAGES

HODDER: 163-167

What is meant by ‘sequence’ in

programming?

What is meant by ‘selection’?

Give two examples of programming

constructs which use selection. 1. 2.

What is meant by ‘iteration’?

Give two examples of programming

constructs which use iteration. 1. 2.

Read the following pseudocode

example.

Identify an instance of sequence,

selection and iteration.

1 START program

2 INPUT A

3 INPUT B

4 FOR j = 1 to 10

5 C = (A +B)/2

6 IF A=B-4

7 A = 6

8 B = 13

9 END IF

10 NEXT j

11 OUTPUT C

12 END program

Sequence:

Selection:

Iteration:

HANDLING

DATA IN

ALGORITHMS

HODDER: 168-175

Explain what is stored by each of the

following data types: Integer:

Real/float:

Boolean:

Character:

String:

2.1.7 Programming


HANDLING

DATA IN

ALGORITHMS

(CONTINUED)

Suggest an appropriate data type to

store each of the following data items.

The quick brown fox jumps over the lazy dog

A

872.15

54

TRUE


variables and constants.


declaration and assignment.

What is an array used for?

What is meant by the dimension of an

array?

TESTING

HODDER: 176-183

Why is it important that programs are

tested?

What is a syntax error?

Give an example of a common cause of

syntax error.

What is a logic error?

Give an example of a common logic

error.

2.1.7 Programming


Fundament als of Comput er System

TESTING

(CONTINUED)

Explain the difference between valid

extreme and invalid extreme test data.

If working correctly, how should a

program deal with erroneous test

data?

What name is given to test data which

is out of range and should be rejected

by the program, but is the correct type

of input?

What name is given to acceptable test

data which is in the correct range?

Consider a very simple program which

outputs whether an inputted integer

between -100 and 100 is positive,

negative or zero.

For each of the different types of test

data, name the type and give two

appropriate examples of data to test

this program with.

Type Example Test Data

computing | gcse | ocr - langdon park school - home · ocr gcse computing learning grids – h/w...

Documents