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3.1: Network Characteristics Exam Board: Eduqas / WJEC Specification: 2020 + What is a network? A network is more than one computer system connected together allowing for communication and sharing of resources . There are many benefits but also some drawbacks to using a network compared to having an unconnected ('standalone' ) computer: Advantages of Networks Easily share files , software and hardware between computers. Disadvantages of Networks There is an initial cost because network devices like routers are required . Larger companies will need to buy and maintain a server . Log in from any connected computer and access your data and files. A network manager / administrator might need to be employed to maintain the network . An administrator can monitor network activity and control security settings. Data from computers on the network can be automatically backed up on central storage. Security breaches are more likely and malware , such as worms, can spread quickly across the network. If the web server fails , all connected computers won't be able to access files or log on . Network Types Networks can be split into different types , usually categorised by their geographical distance apart and the area that they serve. Local Area Network A local area network (LAN ) has computer systems situated geographically close together , usually within the same building or small site , like a school or office . Wide Area Network A wide area network (WAN ) has computer systems situated geographically distant to each other, possibly across a country or even across the world . The internet is an example of a WAN that spans the globe. Personal Area Network A PAN is a personal network for an individual , such as a photographer connecting a smartphone, desktop computer and printer together. Metropolitan Area Network A MAN is larger than a LAN but smaller than a WAN and typically covers a relatively large area like a university campus, town or city . Virtual Private Network A VPN allows for a secure and encrypted connection to a public network like the internet. It is often used to protect an individual's privacy by concealing their real location. Wired & Wireless Networks Wired Connections Wireless Connections Wireless connections, such as WiFi or Bluetooth , use no cables but require a wireless network interface card (WNIC ). Wireless connections generally have a slower speed and can be affected by the computer's distance from the wireless router as well as obstacles like walls or bad weather. Wired connections use physical cables , such as copper or fibre optic wires , and require a network interface card (NIC ) to connect to a network. These wired connections use a wired connection protocol - most commonly Ethernet . Restricted Movement Faster More Secure NIC Required Freedom of Movement Slower Less Secure WNIC Required Q uesto's Q uestions 3.1 - Network Characteristics: ​ 1. A retirement home for the elderly is considering installing a LAN , give 3 benefits and 3 drawbacks they might find of using a network . [6 ] ​ 2a. Describe the difference between a LAN and WAN . [2 ] 2b. Give an example of how a LAN and a WAN could each be used . [ 2 ] ​ 3 . Explain the differences between a PAN , MAN and VPN . [ 3 ] ​ 4. For each of the scenarios below, state which network type would be most suitable : a. The IT rooms of a secondary school . [ 1 ] b. A study in a house with a desktop and printer. [ 1 ] c. Using online banking when abroad on a holiday to stay secure . [ 1 ] d. A large technology company with offices across Europe . [ 1 ] e. Council offices with several locations across Manchester . [ 1 ] ​ 5. Briefly compare wired and wireless networks . [ 8 ] 2.2 - Boolean Algebra 3.2 - Data Packets & Switching Theory Topics

2.1: Logical Operators & Truth Tables Exam Board: Eduqas / WJEC Specification: 2020 + What is a logical operator? Inside of each computer system are millions of transistors . These are tiny switches that can either be turned on (represented in binary by the number 1 ) or turned off (represented by 0 ). ​ Logical operators are symbols used to represent circuits of transistors within a computer. The four most common operators are: ​ NOT AND OR XOR What is a truth table? A truth table is a visual way of displaying all possible outcomes of a logical operator. The input and output values in a truth table must be a Boolean value - usually 0 or 1 but occasionally True or False. NOT A NOT logical operator will produce an output which is the opposite of the input . ​ NOT is represented by a horizontal line . Boolean Algebra Notation written as NOT A A Truth Table AND An AND logical operator will output 1 only if both inputs are also 1 . ​ AND is represented by a full stop. Boolean Algebra Notation written as A AND B A.B Truth Table OR An OR logical operator will output 1 if either input is 1 . ​ OR is represented by a plus. Boolean Algebra Notation written as A OR B A+B Truth Table XOR An XOR (exclusive OR) logical operator will output 1 if the inputs are different and output 0 if the inputs are the same . ​ XOR is represented by a circled plus. Boolean Algebra Notation written as A XOR B A B Truth Table Multiple Operations Exam questions will ask you complete truth tables that use more than one logical operator . Work out each column in turn from left to right and look carefully at which column you need to use. Simplification You may be asked to use a truth table to simplify an expression . ​ This is actually really easy. Once you've completed the truth table see if any columns match the final expression . A+B and A+(A+B) both result in the same values , therefore: A+(A+B) can be simplified as just A+B. Q uesto's Q uestions 2.1 - Logical Operators: ​ 1. Copy and complete the following truth tables: ​ ​ ​ 1b. Simplify the expression in the second truth table. ​ 2a. A cinema uses a computer system to monitor how many seats have been allocated for upcoming movies. If both the premium seats and the standard seats are sold out then the system will display a message. State the type of logical operator in this example. 2b. For the more popular movies, the cinema's computer system will also display a message if either the premium seats or the standard seats have exclusively been sold out. However, it will not output a message when both have been sold out. State the type of logical operator in this example. 1.6 - Additional Hardware 2.2 - Boolean Algebra Theory Topics

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top Python 5e - More Libraries Clear Screen Importing the os library and using the .system() command with the "clear" parameter will clear the screen . ​ ​ The console won't clear on offline editors like IDLE but will work with many online editors like Replit. import os ​ print ( "Hello" ) os. system ( "clear" ) print ( "Bye" ) Bye Clear Screen Task ( Trivia Questions ) Ask three trivia questions of your choice to the user and clear the screen between each one. You should display the total they got correct after the third question - to do this you need to set a variable called correct to equal 0 at the start and then add 1 to correct each time a correct answer is given . Example solution: The Math Library The math libraries contains several commands used for numbers: ​ ​ sqrt to find the square root of a number. ceil to round a decimal up to the nearest whole number and floor to round down to the nearest whole number. pi to generate the value of pi (π ). The sqrt command will find the square root of a number or variable placed in the brackets and return it as a decimal number . from math import sqrt ​ answer = sqrt(64) print (answer) 8.0 The ceil command rounds a decimal up to the nearest integer and the floor command rounds a decimal down to the nearest integer . from math import ceil, floor ​ answer = 65 / 8 print ( "True answer:" , answer) print ( "Rounded up:" , ceil(answer)) print ( "Rounded down:" , floor(answer)) True answer: 8.125 Rounded up: 9 Rounded down: 8 The pi command generates a pi value accurate to 15 decimal places . Pi is used for many mathematical calculations involving circles . ​ The area of a circle is pi x radius² . The first example below uses 5.6 as the radius . from math import pi ​ radius = 5.6 area = pi * (radius * radius) print ( "The area of the circle is" , area) The area of the circle is 98.5203456165759 The example below uses an input to allow the user to enter a decimal (float ) number for the radius. It also uses the ceil command to round the area up . from math import pi, ceil ​ radius = float(input( " Enter the radius: " )) area = pi * (radius * radius) print ( "The area of the circle is" , ceil(area)) Enter the radius: 2.3 The area is 17 Clear Screen Task ( Area of a Sph ere ) The formula of a sphere is 4 x π x r² where π represents pi and r is the radius . Use an input line to enter the radius and then calculate the area of the sphere . Round the answer down to the nearest integer using floor and print it. Example solution: Enter the radius: 7.1 The area of the sphere is 633 ⬅ 5d - Coloram a Section 5 Practice Tasks ➡

1.2 Computer Components Exam Board: OCR Specification: 2016 - Unit 1 This page describe the various components inside of computer systems . The first three are necessary in every type of computer: Processor Motherboard Power Supply Unit A processor's main role is to manage the functions of a computer system by processing data and instructions . The primary processor of each computer system is the Central Processing Unit ( CPU ). The motherboard is the main circuit board of a computer on which components such as the CPU and ROM are connected . ​ The motherboard contains PCI slots for expansion cards and ports for external devices. The power supply unit (PSU) converts electricity from AC (Alternating Current) from the mains power supply to DC (Direct Current) which the computer system can use . ​ The PSU of desktop computers is internal whereas portable devices require an external 'charger'. Memory Memory is split into two types - volatile and non-volatile . Volatile storage is temporary (data is lost whenever the power is turned off). ​ ​ Non-volatile storage saves the data even when not being powered, so it can be accessed when the computer is next on and can be stored long-term . Random Access Memory (RAM) Read-Only Memory (ROM) Cache Memory RAM is volatile (temporary) storage that stores all programs that are currently running . RAM also stores parts of the operating system to be accessed by the CPU. ​ RAM is made up of a large number of storage locations, each can be identified by a unique address . ROM is non-volatile storage that cannot be changed . ​ ROM stores the boot program / BIOS for when the computer is switched on. The BIOS then loads up the operating system to take over managing the computer. Cache memory is volatile (temporary) storage that stores data that is frequently accessed . It is very quick to access because it is closer to the CPU than other types of memory like RAM. RAM ( R andom A ccess M emory) ROM ( R ead O nly M emory) Cache Memory Secondary Storage Magnetic Storage Optical Storage Optical Storage Characteristics: ​ X - Low CAPACITY : 700 MB (CD ), 4.7 GB (DVD ), 25 GB (Blu-ray ). X - Not DURABLE because discs are very fragile and can break or scratch easily. ✓ - Discs are thin and very PORTABLE . ​ X - Optical discs have the Slowest ACCESS SPEED . ​ ​ Magnetic Disks are spelled with a k and Optical Discs have a c. Magnetic Storage Characteristics: ​ ✓ - Large CAPACITY and cheaper per gigabyte than solid state . ​ X - Not DURABLE and not very PORTABLE when powered on because moving it can damage the device. ​ ✓ - Relatively quick ACCESS SPEED but slower than Solid State . ​ Optical storage uses a laser to project beams of light onto a spinning disc, allowing it to read data from a CD , DVD or Blu-Ray . ​ This makes optical storage the slowest of the four types of secondary storage. ​ Disc drives are traditionally internal but external disc drives can be bought for devices like laptops. A magnetic hard disk drive (HDD ) is the most common form of secondary storage within desktop computers. A read/write head moves nanometres above the disk platter and uses the magnetic field of the platter to read or edit data. Hard disk drives can also be external and connected through a USB port . An obsolete (no longer used) type of magnetic storage is a floppy disk but these have been replaced by solid state devices such as USB sticks which are much faster and have a much higher capacity. Another type of magnetic storage that is still used is magnetic tape . Magnetic tape has a high storage capacity but data has to be accessed in order (serial access ) so it is generally only used by companies to back up or archive large amounts of data . Solid State Storage Cloud Storage When you store data in 'the cloud', using services such as Google Drive or Dropbox, your data is stored on large servers owned by the hosting company . The hosting company (such as Google) is responsible for keeping the servers running and making your data accessible on the internet . ​ Cloud storage is typically free for a certain amount of storage. For example, as of 2019, Dropbox allow 2 GB for free or 2 TB for £9.99 a month. ​ Cloud storage is very convenient as it allows people to work on a file at the same time and it can be accessed from different devices. However, if the internet connection fails , or the servers are attacked then the data could become inaccessible . There are no moving parts in solid state storage. SSD s (Solid State Drives ) are replacing magnetic HDDs (Hard DIsk Drives) in modern computers and video game consoles because they are generally quieter , faster and use less power . ​ A USB flash drive ( USB stick ) is another type of solid state storage that is used to transport files easily because of its small size. ​ Memory cards , like the SD card in a digital camera or a Micro SD card in a smartphone , are another example of solid state storage. Solid State Characteristics: ​ X - High CAPACITY but more expensive per gigabyte than magnetic . ​ ✓ - Usually DURABLE but cheap USB sticks can snap or break . ​ ✓ - The small size of USB sticks and memory cards mean they are very PORTABLE and can fit easily in a bag or pocket. ​ ✓ - Solid State storage has the fastest ACCESS SPEED because they contain no moving parts . Cloud Storage Characteristics: ​ ✓ - Huge CAPACITY and you can upgrade your subscription if you need more storage. ​ ✓ / X - Cloud storage is difficult to rank in terms of PORTABILITY , DURABILITY and ACCESS SPEED because it depends on your internet connection. A fast connection would mean that cloud storage is very portable (can be accessed on a smartphone or tablet) but a poor connection would make access difficult . Storage Protocols SCSI (Small Computer System Interface) is a protocol (set of rules) for attaching external devices to a computer system, such as a printer, storage drive or scanner. SAS (Serial Attached SCSI) is an improved version of SCSI that enables many more external devices (up to 128) to be connected at the same time to a computer system. Expansion Cards Expansion cards (dedicated circuit boards) have a specific purpose and are attached to the motherboard . ​ Most of the following expansion cards can also exist as integrated components on the motherboard, rather than a separate card. Graphics Card Sound Card Processes graphical data (e.g. videos or animations) and converts it into a displayable output on a monitor . Network Interface Card (NIC) 0010 1011 0101 0101 0110 0111 0101 0001 0101 Sound cards convert analogue sound waves into digital data (binary) when inputting audio through a microphone.​ Sound cards also convert digital data (binary) into analogue sound waves to output audio through speakers or headphones. 0010 1011 0101 0101 0110 0111 0101 0001 0101 Allows computers to connect to networks (such as the Internet ) and enables them to transfer data to other computers. Transfers data between servers across a network. Fibre channel allows for quick transfer speeds and is primarily used to connect data storage to servers in large data centres. Fibre Channel Card Storage Controller Card Required for the computer to manage and use any attached storage devices . Ports A port is the interface between external devices and the computer . Ports allow data to be transferred from and to these devices. USB Port Connects storage devices such as USB sticks or external hard drives . Connects input devices such as a keyboard or mouse, as well as other devices for data transfer such as a camera or smartphone. Ethernet Port Connects computers to network devices such as a modem or router, allowing access to the internet . Firewire Port Similar to USB but developed for Apple products, Firewire transfers data at a high speed from devices such as camcorders and external hard drives . SATA Port Allows data transfer to external HDD , SSD or optical drives . SD Port Enables data from an SD card to be transferred from a device like a camera to the computer. Micro SD Port Allows data from a micro SD card to be transferred from devices such as smartphones , tablets and handheld games consoles to a computer. Q uesto's Q uestions 1.2 - Computer Components: ​ Vital Components: 1. Describe the purpose of the following components : a. The CPU (Central Processing Unit ) [2 ] b. The motherboard [2 ] c. The PSU (Power Supply Unit ) [2 ] ​ Primary Memory: 2a. What is the difference between primary and secondary memory ? [2 ] 2b. What is the difference between volatile and non-volatile storage ? [2 ] 2c. For each of the three types of primary memory , describe its role and give an example of what it can store. [6 ] ​ Secondary Storage: 3a. For magnetic , optical and solid-state storage rank these three secondary storage mediums in terms of capacity , durability , portability and speed . [9 ] 3b. For the following scenarios justify which secondary storage medium should be used and why it is the most appropriate : ​ Sending videos and pictures to family in Australia through the post. [3 ] Storing a presentation to take into work. [3 ] Storing project files with other members of a group to work on together. [3 ] Backing up an old computer with thousands of file to a storage device. [3 ] Additional Components: 4a. State the purpose of five different expansion cards . [5 ] 4b. What is the purpose of the motherboard ? [2 ] ​ Ports: 5a. Describe the six different ports . [6 ] 5b. What is the difference between SCSI and SAS ? [2 ] 1.1 - Computer Hardware Topic List 1.3 - Computer System Types

App Inventor Tasks 4, 5 & 6 - Using Variables This page will teach you how to make three simple apps that use variables . ​ These apps will prepare you for the final program - the Pop-up Blob game. App #4 - Button Masher The first app to make is a simple program that counts how many times a button is pressed (but don't press it too much! ) This app will introduce you to using variables in App Inventor. ​ ​ ​ Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. ​ App Inventor 2 Firstly, grab a button and two labels and place them in the Viewer . ​ Using the Properties tab, you need to make the following changes: Button Text to 'Press Me!' Button Height to 60 pixels and Width to 'Fill parent...' Label 1 Text to 'Number of Presses' Label 2 Text to '0' Both Label 1 and Label 2 Width to 'Fill parent...' Both Label 1 and Label 2 TextAlignment to 'centre : 1' In the Components tab change the component names to be easier to code later. Switch to Blocks layout and drag an initialize global to block into the centre. In the blank space type 'Presses' - this is the name of the variable that will store how many times the button has been pressed. ​ Drag a 0 block from Math. This will set the number of presses to 0 when the app starts. Drag a when ButtonPresses Clicked from the ButtonPresses section and add the necessary code inside. ​ This code increases the variable value of Presses by 1 every time the button is clicked. It also changes the LabelPresses text to display the number of presses. Improve Your App ​ As you will have seen in the video at the top, I programmed the app to go a bit crazy when 35 presses were recorded. In the code below I have shown how to use an if then block to check if the number of presses is 35. If it is then I have made the button invisible - this is an important feature we will use in later programs. Copy this code and add the following features to the then part of the if statement: ​ ​ Set the background colour to black. Change the Label1 Text Colour to white. Change the Label1 Text Size to 40. Change the Label1 Text to 'You broke it...' Program 4 Complete! App #5 - Timer The second app to make is a timer that counts up one second at a time. It also needs a reset button that sets the timer back to 0 again. It will introduce you to the clock component and enabling / disabling components. ​ ​ Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. ​ App Inventor 2 The code for this program is straightforward; it will take more effort getting the layout right. ​ In the Palette tab, drag a HorizontalArrangement from the Layout section. It will look like an empty grey box at first. Grab a Button as well and place it underneath. ​ Now drag two labels into the grey box and place the second one directly after the first, it may take a few attempts to get them to appear side by side like below: The last component to drag over is Clock (it is in the Sensors section in the Palette tab). It will go into its own section underneath: Change the name of some of the components so that they make more sense. ​ Now to make some changes in the Properties tab. You should know enough by now to work out how to change your components so that it looks like this in your Viewer : Change your layout to Blocks and add the code blocks to the right. ​ This code makes the Label named Seconds update by 1 every second, just like a timer. The code to the left will make the Label named Seconds reset to 0 when the button is pressed. Improve Your App ​ As you will have seen in the video at the top of this task, I added a pause/unpause button that will set the enabled feature of the timer to true or false. You will need to complete the following steps (I've been deliberately vague to make it a challenge - break it down into small steps and use the colours to help you): ​ Add a new button. Add code that, when the new button is clicked , checks if the TimerEnabled is true . If it is, then change TimerEnabled to false . Else change it to true . Now you also need to change the Text of the Button to read either "Pause" or "Unpause" . Program 5 Complete! App #6 - Windy Day The third app to make is an app that blows leaves around your screen. It will introduce you to random numbers, the canvas and coordinates . ​ Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. ​ App Inventor 2 In the Palette tab, drag a Canvas from the Drawing and Animation section. A Canvas allows sprites (objects) to move around inside of it. ​ In Properties , change the Height and Width of Canvas to 'Fill parent...' for both, so it fills the whole screen. ​ In the Palette tab, drag over five ImageSprites from the Drawing and Animation section and drop them anywhere inside the canvas. ​ Download the leaf picture with all App Inventor images on the basics page here . Upload the leaf image it in the Media tab. ​ In the Components tab change the names of your ImageSprites to be leaf1, leaf 2 etc. ​ For each leaf sprite, in the Properties tab, change the Picture to the leaf you just uploaded and change Height and Width to 30 pixels each. ​ Finally, in the Palette tab, in the Sensors section, drag over a Clock . ​ Your Viewer should look like the image to the left. X axis Y axis 0 300 500 Now for an explanation of coordinates. Each sprite (leaf) has an x coordinate (horizontal) and a y coordinate (vertical). For example, the leaf in the top right would have coordinates of x = 270 and y = 100. Can you work out approximately what the other leaves coordinates would be? ​ What the code blocks below do is randomise the x and y coordinates for leaf1 every second. The word integer means a whole number . ​ Use this code and add to it to make all 5 leaves randomly change coordinates. Improve Your App ​ Add a pause / unpause button, just like in the Timer app that pauses the timer so that the leaves stop blowing (and starts them blowing around again too). ​ Find a nice picture (maybe of a park?) online and upload it in the Media tab. Set this as the Canvas BackgroundImage . ​ Add an audio file of some whooshing (why not record it yourself?). Program 6 Complete! Task 7 KS3 Home

Exam Board: OCR 3.3d - Network Security & Threats Specification: A-Level 2015 An instruction set is a list of all the instructions that a CPU can process as part of the FDE cycle . ​ CPUs can have different sets of instructions that they can perform based on their function. The two most common instruction sets are the simpler RISC (Reduced Instruction Set Computer ) and more complicated CISC (Complex Instruction Set Computer ). Instruction Sets This page is still being updated. Graphical Processing Unit What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? ​ Cache memory is temporary storage for frequently accessed data . ​ Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Q uesto's Q uestions 3.3d - Network Security & Threats: ​ 1. What is cache memory ? [ 2 ] ​ 3.3c - Network Hardware & DNS Theory Topics 3.4a - Web Technologies

4. Hyperlinks HTML Guide Watch on YouTube: A hyperlink is a link to another web page . ​ In this section, you will link your page to a real website, like Wikipedia. ​ Hyperlinks require the anchor tags and Copy a URL Firstly you need to copy the full web address of the web page that you would like to link your page to. Choose an appropriate web page that relates to your chosen topic. Create the Anchor Tag 4. Close the start of the tag . 1. Open the start of the tag . 2. Type href (stands for hypertext reference ). 3. Paste the URL inside speech marks . 5. Type the text you want the user to click on . 6. Time to close the tag . When you save your webpage and run it in a browser you will be able to click highlighted text to open the website you have chosen. Add at least three different hyperlinks to your webpage. Try to add the 2nd & 3rd links without looking at this page - practise makes perfect. Add a Hyperlink within a Sentence You can also create an anchor tag within a sentence. Hyperlinks are important to link webpages together. ​ Next is time for adding pictures! Either change one of your previous hyperlinks to be in the middle of a sentence or create a new one. 3. Text Tags HTML Guide 5. Images

top Python 2B - Inputting Numbers Inputting Whole Numbers in Python To enter whole numbers then you must use the int command. int stands for integer (a whole number ) and is typed before input – don’t forget the double brackets at the end . age = int ( input ( "How old are you? " )) print ( "Have you really lived for " , age , "years?" ) = How old are you? 99 Have you really lived for 99 years? Inputting Numbers Task 1 ( Zoo) Type an input line (with int ) to ask the user how many times they’ve been to the zoo . Print a reply that uses the zoo variable (their answer). Example solution: How many times have you been to the zoo? 3 You've been to the zoo 3 times? I love animals! Inputting Decimal Numbers in Python Using float instead of int allows a decimal number to be entered instead. Again, don’t forget the double brackets at the end . miles = float ( input ( "How far have you walked today? " )) print ( "You really walked for " , miles , "miles? Wow!" ) = How far have you walked today? 5.6 You really walked for 5.6 miles? Wow! Inputting Numbers Task 2 ( Height ) Type an input line (with float ) to ask the user their height in metres. ​ Print a reply that uses the height variable (their answer). Example solution: What is your height in metres? 1.82 You are 1.82 metres tall? Wow! ⬅ 2a - Inputting Text Sect ion 2 Practice Tasks ➡

top Python 5b - Sleep Using Sleep To pause a program, import sleep from the time library . Type the word sleep followed by the number of seconds that you wish the program to break for in brackets . It must be a whole number . ​ Below is an example of a program that imports the sleep command and waits for 2 seconds between printing: from time import sleep ​ print ( "Hello!" ) sleep(2) print ( "Goodbye!" ) You can implement the sleep command within a for loop to produce an effective timer that outputs each second waited to the screen: You could also use a variable instead of a fixed value with the sleep command such as below: from time import sleep ​ for second in range (1,11): print (second) sleep(1) from time import sleep ​ seconds = int ( input ( "How many seconds should I sleep? " )) ​ print ( "Going to sleep..." ) sleep(seconds) print ( "Waking up!" ) Sleep Task ( Slow Calculator) Create a slow calculator program that needs time to think in between calculations. ​ Print a message to greet the user , then wait 3 seconds and ask them to enter a number . ​ Wait another 3 seconds and ask them to enter a second number . Wait 2 more seconds , print “Thinking…” then 2 seconds later print the total of the two numbers added together . Example solution: ⬅ 5a - Rando m 5c - Date & Time ➡

Expansion Cards What is an expansion card? An expansion card is a circuit board that can be inserted into a computer and attached to the motherboard . Two important expansion cards are the graphics card and the sound card . ​ Expansion cards are attached to the PCI slots on the motherboard. PCI stands for Peripheral Component Interconnect. Graphics Card Fan Port (HDMI / VGA) Memory PCI Connector What is a Graphics Card? A graphics card processes video calculations so that it can display images and videos on a monitor . Graphics cards are used by professional video gamers and animators . Any job that focuses on graphics must have a powerful graphics card. A computer without a graphics card relies on the CPU to do the graphical processing instead . Sound Card PCI Connector Sound Chip Transistor Line In Microphone Line Out 1 Line Out 2 Line Out 3 Jacks: What is a Sound Card? Most computers don’t need a dedicated sound card, only musicians and producers who require high-quality sound . When you use a microphone , a sound card converts analogue waves (a voice) into digital data (binary). When you use headphones or speakers , a sound card converts digital data (binary) into analogue waves (sounds). What is the difference between an integrated and dedicated card? An integrated card is directly wired into the motherboard. They are cheaper and generate less power because they use the RAM of the computer. Integrated GPUs are used for laptops as they generate less heat and are used for general computing uses (e.g. web browsing or watching movies). A dedicated card is separate from the motherboard and has to be attached through a PCI slot. They are more expensive and generate more heat , often requiring a fan, because it contains its own processor and memory . ​ Dedicated cards are used by professionals who need higher quality features like better sound or graphics. KS3 Home

Exam Board: Eduqas / WJEC 1.1 The Central Processing Unit (CPU) Specification: 2020 + The Central Processing Unit ( CPU ) is the most important component in any computer system. ​ The purpose of the CPU is to process data and instructions by constantly repeating the fetch - decode - execute cycle . CPU Components The control unit directs the flow of data and information into the CPU. It also controls the other parts of the CPU . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . The registers are temporary storage spaces for data and instructions inside the CPU. ​ The registers are used during the FDE cycle . ​ Five essential registers are explained in 1.2 . Cache memory is used to temporarily store data that is frequently accessed . ​ Cache memory is split into different levels . Level 1 and level 2 (L1 & L2) are usually within the CPU and level 3 (L3) is just outside it. See 1.3 and 1.5 for more information about cache. You should know: The control unit is also known as the controller and cache memory is sometimes called internal memory . Computer Architecture The way a computer is designed and laid out is known as its architecture . ​ The most common type of computer architecture is Von Neumann . Von Neumann Architecture The CPU is the most important component in Von Neumann architecture as it is constantly fetching and decoding instructions from RAM and controlling the other parts of the system . ​ Von Neumann architecture also stores both instructions and data in memory . Being able to store programs in memory allows computers to be re-programmed for other tasks - this enables it to multitask and run several applications at the same time. ​ Data input and output is another key feature of this architecture. ​ An alternative architecture is Harvard , which features the control unit as the most essential component. Q uesto's Q uestions 1.1 - The Central Processing Unit (CPU): ​ 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] ​ 2a. Draw a diagram of the CPU , use the same symbols as shown on this page. [ 4 ] 2b. Label the four main components of the CPU. [ 4 ] ​ 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] ​ 4a. Describe the key features of Von Neumann architecture . [ 3 ] 4b. Explain why storing data in memory is important. [ 1 ] 4c . State an alternative architecture . [ 1 ] Theory Topics 1.2 - The FDE Cycle