EDEXCEL GCSE ICT. Personal Digital Devices

Transcription

1 EDEXCEL GCSE ICT Personal Digital Devices

2 2 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 3 Comparing Devices Comparing Devices In this unit you need to be able to choose suitable digital devices for different types of people and for different purposes. In order to do this you need to develop an understanding of the different factors used to compare digital devices. The prefixes kilo, mega, giga and tera are used in both units of speed and storage, so it is important that you understand what they mean. Speed The speed of a device is usually determined by the speed of its processor. Processor speed is measured in hertz (Hz), this is the number of instructions the processor can carry out in 1 second. For example a processor with a speed of 1 Hz would process 1 instruction per second. Mobile Phone A Mobile Phone B 1.2 Name Abbreviation Size kilo K 1,000 mega M 1,000,000 giga G 1,000,000,000 tera T 1,000,000,000,000 As you can see by looking at the table they go up in multiples of 1,000. Storage This is the amount of space the device has available to store files such as images, music and videos. Therefore the larger the storage capacity of a device the more files you can store on it. Storage capacity is measured in bytes (B) and the prefixes from the table are used as an easy way of measuring multiples of 1,000 bytes. For example the storage capacity of this ipod is 8 GB, this is equivalent to 8,000 MB or 8,000,000 KB. The smallest unit of storage capacity is the bit, there are 8 bits in 1 byte. A lowercase b is used as an abbreviation for bit whereas an uppercase B is used for byte. 1 byte (B) 1 kilobyte (KB) 1 megabyte (MB) 1 gigabyte (GB) 1 terabyte (TB) Modern processors are usually measured in megahertz (MHz) which is 1,000 instructions per second and gigahertz (GHz) which is 1,000,000 instructions per second. Resolution The resolution of a device is the maximum number of pixels (dots that make up the image) it can fit on the screen. The higher the resolution, the more detail can be displayed. Resolution is given in width x height, for example 1024 x 768 is a common screen resolution. Storage 512 MB Storage 16 GB Processor Speed 300 MHz Processor Speed 1 GHz Resolution 320x240 Resolution 360x640 Which mobile phone has the largest storage capacity? (1) Mobile Phone A Mobile Phone B Which mobile phone has the fastest processor? (1) Mobile Phone A Mobile Phone B Question 3: Which mobile phone has the lowest resolution? (1) Mobile Phone A Mobile Phone B

3 4 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 5 Mobile Phones Mobile Phones Mobile phones are everywhere and they have changed the way we live our daily lives. Everyone uses their mobile phone in slightly different ways and as a result different people need different mobile phones. Multifunctional Phones Imagine the first mobile phone. It could only make calls, it couldn t even send text messages! Now with a multifunctional phone (aka smartphone) we can check our , browse the web, play games and so much more! A multifunctional phone is described as a phone that has taken on the features and functions of multiple devices. For example many people don t bother buying a separate digital camera as their mobile phone has one built in. Features This table outlines the main features of mobile phones: Feature Description Limitation Talk Time SMS MMS Camera 3G Bluetooth Music Playback WiFi Mobile Internet GPS The amount of time you can talk on your phone before the battery runs out. Short Messaging Service - allows users to send and receive text messages. Allows users to send pictures, video and sound along with text. A camera built into the phone, which allows you to take photos or record video. Third Generation phone offer highspeed internet access. Allows user to send and receive data from nearby devices (within 50 metres). You can store music and listen to it on the move. Similar to bluetooth, but the range and speed are greater. Browse the internet on your mobile phone. Global Positioning System - uses satellites to find your position and give you directions. The more you talk on your phone, the quicker the battery runs out. You can only send 160 characters per message. Normally pictures are compressed, so they will lose quality. The quality of the pictures depends on the camera resolution. In some areas there is limited or no 3G coverage. Will not work if the device is out of range. Music files can be large, so storage space can become used up quickly. You need to be in range of a wireless network. Limited by the small screen; only works within signal range. Can drain your battery quickly. Security Most multifunctional phones store a lot of personal information that you would not want to get into the wrong hands, so security is an important consideration. There are several steps that you can take to protect your phone: Keeping your phone out of sight so it is less tempting to thieves. Setting a PIN or password so only you can access it. Locking the SIM card. Writing down the IMEI number so your mobile phone can be blocked if it is lost or stolen. Turning off bluetooth to stop bluejacking. Bluejacking is the process of sending unwanted messages to other mobile phones using bluetooth. User Types Different features will be more important to different users, in the table are three different types of users each with a list of features that might be important to them. Business Users Teenagers Senior Citizens SMS Large Screen and Buttons Mobile Internet MMS Lightweight GPS Installable Apps Panic Button QWERTY Keyboard Mobile Internet Limited number of Features Installable Apps Music/Video Player Simple User Interface State two measures you could take to protect the personal information stored on your phone. (2) Give a feature that would make a phone easier to use for a partially sighted user and explain why. (2) Question 3: Explain how you could transfer a photo from one mobile phone to another. (2) 1.5

4 6 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 7 Personal Computers Personal Computers The first computers were so big that they filled an entire room and needed several people to operate them. In the 1970s computers became small enough to fit onto a desk and be operated by one person, thus becoming personal. There are three main types of personal computer Desktop, Laptop /Notebook and Tablet. Each has its own benefits and drawbacks. Desktop Laptop / Notebook Tablet Recommendations You need to recommend a suitable type of computer for the users shown below. For each user you need to select two features that you think will be important to them and explain why. Susan is a business woman that travels all around the world to attend business meetings. She needs to send and receive s and prepare business presentations. Type of computer: Feature 1: 1.6 Feature 2: High Processor Speed Medium Processor Speed Low Processor Speed Not Portable Portable Very Portable Optical Drive May Have Optical Drive No Optical Drive Physical Keyboard Physical Keyboard On Screen Keyboard High Storage Capacity Medium Storage Capacity Low Storage Capacity HDD The Hard Disk Drive is used to permanently store files and applications. The larger the capacity of the HDD the more files can be stored and the more applications can be installed. Users that want to store lots of videos and music will need a large hard disk drive. Many Laptops and Tablets now come with a SSD (Solid State Drive) instead of a HDD. SSDs have no moving parts which makes them more reliable than HDDs, however they are also much more expensive. RAM Random Access Memory holds all the programs and files that are currently open, the more RAM the more you can have open at the same time without the computer slowing down. RAM is wiped when the computer is turned off. Optical Drive Allows you read CD-ROMs and DVD-ROMs in addition to playing CDs and DVDs. Most optical drives also allow you to write data onto disk. Peter is a musician that is setting up a home studio and needs a computer to record his tracks, edit them and burn them to CD. Type of computer: Feature 1: Feature 2: State which type of computer would be most suitable for a PE teacher to use out on the sports field. (1) Explain which type of computer would be most suitable for video editing. (2)

5 8 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 9 Cameras & Camcorders Cameras & Camcorders Digital Cameras The main function of digital cameras is to take photographs, however most modern cameras also allow you to record video. There three main types of digital camera, these are outlined in the table to the right: Zoom It is important to understand the difference between optical and digital zoom. Cameras with optical zoom use a lens to make an object or person appear closer without reducing image quality. Digital zoom uses image processing to enlarge part of the image reducing the quality of the image. This is the same as when you zoom in on an image on a computer. Resolution Digital images are made up of lots of little dots called picture elements (pixels). The number of pixels a camera can capture is measured in megapixels (MP), one megapixel is equal to 1 million pixels. Therefore the higher the number of megapixels the camera can capture the higher the quality of the images. Geotagging Many new cameras are fitted with GPS (Global Positioning System) chips, these allow images to be tagged with the details of the location in which they were taken. Digital Camcorders As previously mentioned most modern digital cameras can also record video. The term digital camcorder is reserved for devices whose main function is to record video. The majority of digital camcorders currently in the shops record high definition (HD) video, this means more detail is captured when compared to the traditional standard definition (SD). Compact Bridge DSLR Small and Light Medium Sized Large and Heavy Fixed Lens Fixed Lens Removable Lens Limited Functions Some Manual Controls Full Manual Controls Beginner Intermediate Advanced Storage Digital cameras use removable memory cards to store images, the most common type of memory card is the SD (secure digital). Many camcorders also use SD cards for storage, however some have an inbuilt HDD which provide a longer recording time. Recommendations You need to recommend a suitable type of camera for the users shown below. For each user you need to select two features that you think will be important to them and explain why. Samantha is going on holiday and wants to buy a new camera to take with her. Type of camera: Feature 1: Feature 2: Harry is a bird watcher and needs to take pictures of birds that are far away. Type of camera: Feature 1: Feature 2: Assessment Type: Date: 1.7

6 10 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 11 Games Consoles Home Entertainment Games consoles were first introduced in the 1970s and were designed to allow users to play simple video games on their TV screens. Modern games consoles are multi-functional devices, they enable people to do so much more than gaming, for example watching films and surfing the Internet. Controllers The current generation of games consoles enable users to control the device with movement, for example by moving their hands. Some consoles still require you to hold a physical controller for this to work, whereas others are totally hands free. It doesn t stop there, new technologies are developing all the time, for example the entire user interface of the Xbox One can be controlled using the voice and hand gestures. Digital advert Media Up until relatively recently most games were distributed to customers using physical media such as CDs, DVDs and Blu-rays. Now many games can be downloaded directly to your console almost instantly without any need for you to leave your house! Portable Gaming A range of handheld consoles are also available which allow to play games on the move, however these are slowly being taken over by smart phones. For many people it simply doesn t make sense to carry around a separate games console when they can play games on their phone. Health There are several health risks associated with the use of games consoles. A common problems include; RSI (Repetitive Strain Injury), eye strain and obesity. There is also the risk of becoming addicted to playing games which can have a negative impact on your social life. Don t worry it isn t all bad news, playing games can also have a positive impact on your health. A range of games and peripherals are now available that are specifically designed to improve fitness levels, for example Wii Fit. Pick one of the consoles from the drop down list and prepare a digital advert designed to persuade people to buy it. Console: The advert must meet the following requirements: Created using PowerPoint Plays without user interaction Includes key features of the console Includes a comparison with similar consoles Includes a special offer Assessment Type: Date: 1.8 Digital TV Digital television services provide us with hundreds of channels to choose from, these have replaced the traditional analogue service which only had five channels. There are three methods that can be used to bring digital tv signals into our homes: Aerial Satellite Cable Most of these methods require a set top box to convert the signal into a form the TV can display. However some TVs come with this ability built in. High Definition High definition TVs (HDTVs) are capable of displaying HD television signals. HD gives a more detailed picture than the traditional standard definition (SD) broadcasts. Each frame of an SD video is made up of 576 lines, whereas HD video has either 720 or 1080 lines. Formats The DVD is a common format used to distribute SD video, however it isn t suitable for HD video as the storage capacity is too small. A new type of disc with a much higher storage capacity called the Blu-ray was created for HD video. So you now have the option of buying films and TV shows on Blu-ray and playing them on a Blu-ray player. The storage capacity of a standard DVD is 4.7 GB compared to 25 GB for a standard Blu-ray disk. Personal Video Recorders Personal Video Recorders or PVRs allow you to record films and TV programmes onto an internal HDD. In addition to this they enable users to pause and rewind live TV, which is really useful if someone calls during your favourite TV show. Popular examples of PVRs are the Sky+ box and TiVO. Smart TVs This term is used to describe TVs that can connect to the Internet in order to access a range of additional features and services. For example on demand TV and games. The ability to install applications enables new features to be added at any time. On Demand A broadband Internet connection gives you access to a range of on demand entertainment services, this means you can watch TV programmes and films when you like. BBC iplayer is an example of an on demand entertainment service. You can access these services using a computer that is connected to the Internet. Many set top boxes and games consoles also provide access to on demand services.

7 12 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 13 Personal Media Players Navigation Aids Personal media players - the name given to portable devices that allow you to play media on the move. There are two main types: Audio Players These are designed just to play audio, for example music and talking books. Often known as MP3 players (named after the popular MP3 audio file format) most now support a range of formats. The cheapest audio players don t have a screen, just simple buttons for example the ipod Touch. If you pay slightly more you can get one with a small LCD screen which allows you to select a song by picking it from a list. Multimedia Players These usually feature a colour screen which makes them suitable for watching video in addition to the ability to listen to music and audio books. State the name of a common audio file format. (1) Convergence This is the name given to the process of devices adopting the features and functions of other devices. Smart phones taking on the features of media players is a good example of convergence. This means that a large number of people no longer carry around a separate media player as their smart phone has a built in media player. 1.9 Global Positioning SYSTEM GPS is used by a range of devices to calculate your current location. It does this using signals from a network of satellites orbiting the Earth. Sat Navs Sat navs are devices that are specifically designed to give you directions based on your current location which is calculated using GPS. These are most commonly found in cars, however some are designed for use on bicycles and motorbikes. There are a range of benefits and drawbacks associated with the use of sat navs in place of traditional paper maps. These are outlined in the table below: Benefits Maps more likely to be up to date Spoken directions Create routes to avoid traffic jams Drawbacks Signal can be lost in tunnels/under bridges May distract the driver Can be a target for thieves Geocaching This is an outdoor activity which makes use of GPS receivers or GPS enabled mobile devices to locate containers, called geocaches. Geocaches usually take the form of a small waterproof container. A log book is kept inside, which the geocacher signs and dates. Smart Phones Many smart phones contain GPS receivers and map apps which enables them to double up as sat navs. This is another example of convergence (see the previous page) Kirtan is organising a walking holiday and is providing each person taking part with a GPS tracker. State three things that could be calculated using the data from these trackers. (3) Smart phones taking on the features and functions of media players is an example of convergence. Describe another example. (2) Describe the function of GPS. (2)

8 14 EDEXCEL GCSE ICT Revision Guide Personal Digital Devices Personal Digital Devices EDEXCEL GCSE ICT Revision Guide 15 Peripherals Extended Questions Peripherals are external devices that you connect to a computer or other digital devices. They fall into three categories, these are shown in the table below: Input Devices Output Devices Storage Devices Input data into a digital device so it can be processed. Output data from a digital device in a form that humans can understand. Allow you to store data and transfer it to other digital devices. Extended Question Practice The question below is an example of an extended question which is worth six marks and takes your use of spelling, punctuation and grammar into account. It is important that you practice answering this type of question. To get you started use this form to help you structure your answer to the following question Discuss the benefits and drawbacks of allowing secondary school students to bring mobile phones into school. There are a range of potential benefits and drawbacks to allowing students to bring mobile phones into school, one benefit is... Keyboard Monitor Memory stick Mouse Speakers External HDD Touch screen Headphones Memory card Choosing Peripherals Think of three peripherals that would be commonly used with each of these devices: 1.11 Another potential benefit is... It is also worth considering that... Although it is clear that there are a range of benefits related to the use of mobile phones in school, the drawbacks also need to be considered. A potential drawback is... Another potential drawback is... After weighing up the potential benefits and drawbacks I have come to the conclusion that... Assessment Type: Date: Revise Personal Digital Devices by taking part in the digital treasure hunt. 1.13