1. Component 1 Revision
Chapter 1 - Hardware

2. Entry ticket: Binary addition & Arithmetic shifting
Add together the binary numbers [3]
Perform arithmetic shifts on the following binary numbers [4]

3. Exit Ticket: Chapter 4 SAT
Cache size, clock speed and number of cores are the three main factors that affect performance. Describe how performance is affected by these three factors [6]
Exit Ticket: Chapter 4 SAT

4. Assessment Outcomes covered
Describe the characteristics of CPU architecture, including Von Neumann architectures
Identify and explain the role of the components of the CPU in the fetch-decode- execute cycle
Explain how performance is affected by the cache size, clock speed and number of cores
Explain the functional characteristics of Random Access Memory (RAM), Read Only Memory (ROM), flash memory and cache memory
Explain the functional characteristics of contemporary secondary storage devices including magnetic, optical and solid state in terms of suitability, durability, portability and speed
Describe the characteristics and role of additional hardware, including GPU, sound cards and motherboards

5. Binary Bits Each 1 or 0 is called a bit - 1
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
Each 1 or 0 is called a bit - 1
8 bits is called a byte – e.g
4 bits is called a nibble – e.g. 1010
In the same way as a kilometre is meters, we can group together bytes and call it a kilobyte
8 bits = 1 byte
1024 bytes = 1 kilobyte
1024 kilobytes = 1 megabyte
1024 megabyte = 1 gigabyte
1024 gigabytes = 1 terabyte
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

6. Binary and Denary (Base 2 and Base 10)
Notice how we organise the number 2564
Converting to Binary
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
There are:
2 x = 2000
5 x 100 = 500
6 x 10 =
4 x 1 =
2564
In binary we don’t use 1, 10, 100, because that’s base 10.
Each column is multiplied by 10!
Instead we use 1, 2, 4, 8, 16, 32..
This is called Base 2 – because each column is multiplied by 2!
1000
100 10 1  2  5  6  4 8 4 2 1
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

7. Base 10 and Base 2
Base 10
Base 2
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

8. Writing down numbers Decimal (Denary) Binary
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
The number 4567 is made up of:
7 x 1
6 x 10
5 x 100
4 x 1000
When you add these you get 4,567
The number 1011 is made up of:
1 x 1
1 x 2
0 x 4
1 x 8
When you add these you get 11
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from
X 2
X 2
X 2
1000
100 10 1 4 6 5 7 8 4 2 1

9. Converting Base 2 to Base 10
To convert from Binary to Denary (Base 2 to Base 10):
Draw the table over the top (1, 2, 4, 8, 16, etc..) from right to left
Add up all of the 1s!
Example:
1011 would become 
Add = 11!
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from 8 4 2 1

10. Converting Base 10 to Base 2
Write down the 8 bit Binary table
Take away the biggest number you can
e.g Converting 84. The biggest number you can take away is 64
Take away the next biggest number
You are left with 20. The next biggest number is 16
Repeat until you get 0!
Fill in the gaps with 0s!
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

11. Converting Binary into Decimal
Method 1
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
Divide the decimal number by 2. If it divides equally write a 0. If it doesn’t divide equally and there is a remainder write 1.
Divide the result by 2. If it divides equally write a 0. If it doesn’t divide equally and there is a remainder write 1.
Continue until the result is 0.
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

12. Converting Binary into Decimal
Method 2
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
Find the largest possible binary bit value that can be subtracted from the decimal value without creating a negative value.
Write a 1 in that column.
Subtract the next largest binary bit value from the decimal without creating a negative value. Write a 1 in that column. If you do create a negative value put a 0.
Keep going until the decimal value is 0.
For example the number 13:
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

13. Hexadecimal Hexadecimal is a base 16 numbering system.
Why do you think 16 is a significant number in Computing?
Convert the binary nibble below.
1111
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

14. Denary and Hexadecimal (Base 10 and Base 16)
Each hex digit reflects a 4-bit binary sequence.
This means an 8-bit binary number can be written using only two different hex digits - one hex digit for each nibble (or group of 4-bits). It is much easier to write numbers as hex than to write them as binary numbers.
For example:
 in binary would be D4 in hex
FFFF3 in hex would be   in binary
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

15. Converting Base 16 to Base 10
Method 1: Converting from hex to denary via binary
Separate the hex digits to find each equivalent in binary, and then piece them back together.
Worked example - What is the denary value of hex value 2D?
Separate the hex digits into 2 and D and find the equivalent binary numbers (2 = 0010; D = 1101).
Piece them together to get   (0x x64 + 1x32 + 0x16 + 1x8 + 1x4 + 0x2 + 1x1 = 45 in denary).
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

16. Converting Base 16 to Base 10
Method 2: Using base 16 place- value columns
Another method is to create base 16 place-value columns, and add the hex value to the appropriate columns. You would then need to work out what the hex digits represent in denary, and multiply this figure with the place-value. Finally, add all the values together.
The base 16 columns would be (161=16), (162=256), (163=4096), etc.
Worked example - What is the denary value of hex value 2D?
Add the hex value to the appropriate base 16 place-value column: 2 in the 16 column; D in the 1 column.
Work out what the hex digits represent in denary: 2 = 2 in denary; D = 13 in denary.
Multiply this figure with the place value: 2 x 16 = 32; 13 x 1 = 13.
Add the values together: = 45 in denary.
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

17. Graded Exercises – Grade 4
Complete the Q21 sheet
You can use the Q19 Sheet to help you – this can be found in the help folder for this lesson!
Remember to be smart when using the Internet:
Wikipedia is often complicated – sometimes even I don’t understand!
BBC Bitesize, Teach ICT, and Revision World are better places to find your information!
To be able to convert between Binary, Denary, and Hexadecimal
To be able to perform Binary Addition
To understand the advantages of Hexadecimal over Binary
To understand the relationships between Base 2, 10, and 16
How do you convert from Binary to Denary?
How do you convert from

18. Character sets
A character can be a letter, digit, space, punctuation mark or various other symbols. When characters are stored on a computer system, they are stored as a binary number.
It is important that computer systems recognise that characters can be represented differently by other computer systems; otherwise data could not be exchanged between computers.
A character set is a table that maps a character with a unique binary number. A character set is a method of storing the characters and their binary values. This helps different computers convert messages from one to another.

19. ASCII One of the most common character sets is called ASCII.
ASCII is the 7-bit American Standard Code for Information Interchange (ASCII).
Denary
Binary
Hex
Character 32
100000 20
space 33
100001 21 ! 34
100010 22
" 35
100011 23 # 36
100100 24 $ 37
100101 25 % 38
100110 26
& 39
100111 27 ' 40
101000 28 (

20. ASCII Table Denary Binary Hex Character 32 100000 20 space 64 100000040 @ 96 60 ` 33
100001 21 ! 65 41 A 97 61 a 34
100010 22
" 66 42 B 98 62 b 35
100011 23 # 67 43 C 99 63 c 36
100100 24 $ 68 44 D
100 d 37
100101 25 % 69 45 E
101 e 38
100110 26
& 70 46 F
102 f 39
100111 27 ' 71 47 G
103 g
101000 28 ( 72 48 H
104 h
101001 29 ) 73 49 I
105 i
101010 2A * 74 4A J
106 6A j
101011 2B + 75 4B K
107 6B k
101100 2C , 76 4C L
108 6C l
101101 2D - 77 4D M
109 6D m
101110 2E . 78 4E N
110 6E n
101111 2F / 79 4F O
111 6F o
110000 30 80 50 P
112 p
110001 31 1 81 51 Q
113 q
110010 2 82 52 R
114 r
110011 3 83 53 S
115 s
110100 4 84 54 T
116 t
110101 5 85 55 U
117 u
110110 6 86 56 V
118 v
110111 7 87 57 W
119 w
111000 8 88 58 X
120 x
111001 9 89 59 Y
121 y
111010 3A : 90 5A Z
122 7A z
111011 3B ; 91 5B [
123 7B {
111100 3C
<  92 5C \
124 7C |
111101 3D = 93 5D ]
125 7D }
111110 3E
>  94 5E ^
126 7E ~
111111 3F ? 95 5F _

21. ASCII – The problem
The problem with using this ASCII character set is that it is only able to represent 128 different characters and computer systems need to be able to store more characters than this.
For example, you may have noticed that the £ character is missing from the table above. As a result, other character sets were developed and used to allow computer systems to store more characters.

22. Unicode
Unicode is a standard character set that has combined and replaced many others. It was originally an extension to the ASCII character set and it contains many of the characters used around the world.
To see the different characters that are available with Unicode go to – there are too many for this presentation!

23. Benefits of Networks: Communication
Using to communicate with colleagues
Using messaging systems to chat while you are working on other things
Transferring files between computers

24. Benefits of Networks: Sharing Resources
Sharing folders so that you can access files anywhere on the network from any computer and different people can access these files as needed
Sharing peripheral devices such as printers and scanners
Sharing an internet connection

25. Benefits of Networks: Centralised Management
User profiles and security can all be managed centrally
Software can be distributed across the network rather than having to install it on each individual computer
Users can use any PC on the network but still see their own files.

26. Disadvantages A network manager may need to be employed – expensive
Security problems – files sent between computers could spread a virus
Hackers can gain access to data more easily
If the server is down, all workstations on the network are affected
Initial cost of servers, communication devices, etc. can be expensive

27. Binary Logic
As computers use transistors and capacitors to store binary data we can wire them together to make simple logical calculations
These simple circuits are known as logic gates
There are four fundamental gates you know need to know about:
NOT gate
AND gate
OR gate
XOR gate (Exclusive OR gate)

28. Binary Logic – Not Gate Logic Diagram If 0 is input it outputs 1
Boolean Algebra: P = A’
P = A
Logic Diagram

29. Binary Logic – AND Gate Logic Diagram
If both inputs are 1 then the output is 1
Otherwise the output is 0
INPUT A B
OUTPUT P
Boolean Algebra: P = A.B
P = AB
P = AxB
Logic Diagram

30. Boolean Algebra: P = A + B
Binary Logic – OR Gate
If either input is 1 then the output is 1
Otherwise the output is 0
INPUT A B
OUTPUT P
Boolean Algebra: P = A + B
Logic Diagram

31. Boolean Algebra: P = A ⊕ B
Binary Logic – XOR Gate
If either input is 1 then the output is 1
UNLESS! Both are 1!
Otherwise the output is 0
INPUT A B
OUTPUT P
Boolean Algebra: P = A ⊕ B
Logic Diagram

32. Image Representation: Bitmap Graphics
Bitmap Images on a computer system are made up of thousands of small coloured dots, known as pixels (short for picture elements).
Bitmap images are stored as an array of pixels.
A black and white bitmap image will store a 1 for a black pixel and 0 for a white pixel.

33. Resolution A Bitmap image is made up of a grid of pixels.
An image could be 600 pixels wide by 400 pixels high.
The resolution of this image would be 600X400.
If the resolution is increased the quality, not the physical size, is increased and it takes up more of memory to store it.

34. Making an image file
For a picture of a flower four colours are used. These numbers are represented as binary.
The number of bits we use dictates how many colours we could use. If we wanted to store more than 4 colours we would have to use more than 2 bits.

35. Making an image file
We take the information from the image file and build a image data file
We read left to right. Top to bottom.

36. Meta Data
For the computer to interpret an image file and rebuild the picture it must know some other things about this data file. For example…
The width is 8
The colour depth is 2 bits per pixel
What colour is each pixel
Without metadata, a computer system may render an image incorrectly on screen, such as displaying all pixels in one row.
Other data may also be stored in the metadata of an image file, such as the date the image was made, the geographical location of a photograph.

37. Making an image file with metadata
We put the information about the image file (width, bit depth) before the information to make it
We take the information from the image file and build a image data file
We read left to right. Top to bottom.

38. Compression
Compression is the process of reducing the size of a file. It is particularly beneficial to compress multimedia files such as images, videos and audio as these typically use a lot of storage space. Multimedia files are often compressed so they take less time to transfer over the Internet. Other file types, such as text, can also be compressed. An uncompressed image might be 20 MB A Compressed image might be 1MB They are both the same image!

39. Types of Compression There are two types of compression: Lossy:
The data is compressed by permanently removing parts of the data that aren’t needed.
When the file is compressed something is lost. This can be colour/quality/size.
Takes no time to uncompressed.
Lossless :
The data is compressed without permanently removing any data.
When the file is compressed nothing is lost.
It takes time to uncompressed the file

40. Lossy compression - Images
Lossy image compression uses a mathematical algorithm to figure out what colour each pixel is and to merge some of these colours together.
For example, # and # are very similar colours and the user probably wouldn’t notice if they were combined into the same colour!
JPG is an example of a lossy picture codec. Each time you save a picture as a JPG, a little bit of information is lost, although it would be hard for most people to tell the difference.
Summary
JPEG is an example of lossy compression in images.
It combines similar colours that are next to each other to reduce the total numbers of colours used, this means there is less data to store in the file.
Because the colours were similar in the first place this should mean that it isn’t obvious to see.. However if too many colours are combines it can distort the image.

41. Lossless Compression: Run-Length Encoding
64 Bytes  34 Bytes is a compression ratio of:
34/64 = 0.53
This means we have saved 47% of the file size because the compressed version is 53% of the original size!
Notice that we don’t compress sequences of letters shorter than four; this is because our notation for highlighting repeated characters is itself three characters long, so the pay-off between the time taken to compress and the compression ratio achieved makes it pointless.
This will take 8 Bytes per row if each Pixel is 1 Byte
This will take less than 8 Bytes per row if each Pixel is 1 Byte B G 8 R
$B5 G 6
$B6 5
$B7 R 4
$G8 3
Total File Size = 64 Bytes
Total File Size = 34 Bytes

42. Lossless compression
In 'lossless compression', the algorithms keep all of the information about a file.
The compressed file, once decompressed, can be reconstructed so it is exactly like the file before it was compressed, with no loss of any information at all.
This would be very important if you needed to get access to the highest quality file possible, the original file, without any loss of data – for example if you are decompressing text or source code! 

43. Lossless Compression: Run-Length Encoding
This will take 8 Bytes per row if each Pixel is 1 Byte
This will take less than 8 Bytes per row if each Pixel is 1 Byte
64 Bytes  34 Bytes is a compression ratio of:
34/64 = 0.53
This means we have saved 47% of the file size because the compressed version is 53% of the original size! B G 8 R
$B5 G 6
$B6 5
$B7 R 4
$G8 3
Total File Size = 64 Bytes
Total File Size = 34 Bytes

44. Data Types Data type Description Examples
Integer
Whole numbers, positive or negative
42, -11, 0
Real
Numbers, including fractions or decimal points
12.9, , 28.0
Boolean
True or false
1 or 0
Character
Letter, digit, space, punctuation mark or various other symbols
'A', 'b', '7','?'
String
A sequence of characters
‘Computer science’
‘The cat sat on the mat’

45. Strings and Characters
The String or Character data type can hold any letter, number, symbol or punctuation mark. It is sometimes referred to as 'alphanumeric' or 'string'.
The data can be pure text or a combination of text, numbers and symbols.
In python we make a variable a string by putting str() around it:
Name = str(“Alex”)
Examples of text data types in use:

46. Integers
Integers are whole numbers represented as binary values. Most programming languages provide a data type called 'integer', often called 'int' for short.
In python we make a variable an integer by putting int() around it:
Age = int(15)

47. Real (Floats)
Floating point numbers are numbers that have a fractional part, usually represented using two components: the main number and the fractional part, each of which is a binary number. This is known as a floating-point representation. Most programming languages provide one or more data types based on floating-point representations. They are usually given names like 'float', 'single', 'double', 'real' or 'longreal'.
In python we make a variable a float by putting float() around it:
Pi = float(3.14)

48. Booleans Boolean data holds one of two allowable values, for example:
Yes or No
True or False
A Boolean data type is used to answer questions that have exactly two responses. If a third response were present it is not Boolean data
Examples of Boolean data questions:
Are you over 15?
Do you have a job?
Do you have blue eyes?

49. Validation
For example you might ask someone to input their date of birth.
My date of birth is 25/03/1991..
But I could enter 07/05/1989 if I wanted to.
Both sets of data are valid because they are both sensible – however
Validation is a process to check that input data is reasonable or sensible. Frequently used validation algorithms include;
Presence checks
Used to prevent further progress if a required field is left blank.
Format checks
Used to ensure data matches a specific pattern, such as dd/mm/yyyy for a date. Input masks are often used to create format checks on database forms.
Length checks
Used to ensure an input data string is a sensible length e.g. number of characters in ‘firstName’ to be between 3 and 16
Type checks
Used to ensure input data is a particular data type e.g. quantity ordered to be integer or cost to be real.
Range checks
Used to ensure input data lies within a specified range e.g. over time hours to be > 0 and < 15.

50. Verification
Verification is a process for checking data is correct. It can be carried out as a user enters data, such as via a keyboard and also when data is copied from one part of a system to another. Copying should not change the data.
Examples of verification of user input include double entry and screen based verification.
Double entry involves comparing two versions of data input. e.g.” re- enter your address”. A verification algorithm will compare the two versions and inform the user if they are not identical.
Surname
String
National Insurance (NI) number
Standard format LL123456L
Job title
Apprentice, semi-skilled, skilled, supervisor
Week no.
Integer
Full time
Y or N, Full time = 38 hours per week
Hours worked
Integer, hours worked in current week, maximum 10 hours overtime in one week.
Overtime rate = 1.5 x pay rate
Pay rate
Real, hourly pay rate, max £ / hour

51. Crib Sheet Exercises
Explain the functional characteristics of Random Access Memory (RAM), Read Only Memory (ROM), flash memory and cache memory
What is the purpose of Random Access Memory?
What is the purpose of Read only Memory?
What is stored in RAM?
What is stored in ROM?
What is Flash Memory?
What is Cache Memory? What is it used for?
Explain the functional characteristics of contemporary secondary storage devices including magnetic, optical and solid state in terms of suitability, durability, portability and speed
What is the purpose of secondary storage?
Give an example of magnetic storage
Give an example of optical storage
Give an example of Solid State storage
Explain which storage media is most suitable for:
Backing up files onto a server
Taking documents home from school
Storing media
Exam Questions:
Get an exam question from the front – once you’ve completed it you need to red pen it using the mark schemes.
Once you’ve red penned it, get me to check it.

52. Describe the characteristics and role of additional hardware, including GPU, sound cards and motherboards
Motherboard
The motherboard is the main circuit board of a computer. The CPU and ROM will be mounted on the motherboard, which also provides RAM expansion slots, USB ports, PCI slots for expansion cards and controllers for devices such as the hard drive, DVD drive, keyboard, and mouse.
Graphics Processor Unit GPU
A GPU is a microprocessor that performs the calculations needed to produce graphic images on screen. Initially the CPU performed these calculations, but as more complex applications were developed, such as 3D graphics and video quality animations, the GPU was introduced to offload those tasks from the CPU.
GPUs can be integrated within the circuitry of the motherboard, or provided on a dedicated graphics card.
Integrated GPU An integrated GPU uses the computer’s RAM. An integrated unit is cheaper than installing a dedicated GPU, it generates less heat and uses less power. They are perfect for general graphics processing such as watching or editing videos and word processing.
Dedicated GPU A dedicated GPU has its own video memory. Dedicated cards provide the best visual experience and are used by people such as professional graphic designers and serious gamers, but they use more power and require a good cooling system.
Sound cards
Sound cards may be on board (on the motherboard) or designed to fit a PCI slot. They enable the computer to output sound through speakers, to record sound from a microphone and to manipulate sound stored on a disk. Sound cards convert analogue input signals into digital data and reverse this process for audio output.

53. Crib Sheet Exercises Describe the purpose of each piece of hardware:
Motherboard
Graphic Processing Unit
Sound Card
Explain how a Computer can be improved for playing games by adding additional hardware components
Exam Questions:
Get an exam question from the front – once you’ve completed it you need to red pen it using the mark schemes.
Once you’ve red penned it, get me to check it.