IGCSE CIE ICT: 1 Types and components of computer systems
central processing unit
The part of the computer that interprets and executes commands from computer hardware and software.
software
The term to describe programs that control computer systems or the processing of electronic data. Such as systems software and applications programs.
hardware
The term to describe the physical components that make up the computer (e.g. keyboard, mouse).
applications software
Software that enables a user to carry out a specific function on a computer e.g. spreadsheet, word processor, database, etc.
Command Line Interface (CLI)
An operating system is a software program that manages computer resources. Operating systems allow components to communicate with each other and enables the computer to run software applications. A command line interface is an older style operating system where users type in commands using keyboard. 1.Accepts inputs from keyboard. 2.Sends outputs to the monitor or printer. 3.Recognises peripheral devices such as external hard disks, pen drive, web cam etc and makes sure that software needed for the hardware to run is installed. 4.Manages files and folders in the system (Naming, Creating, Moving, Finding and Deleting folders etc). 5.Allows applications software (word-processing, spreadsheets etc) to communicate with the system's hardware. 6.Shares out system memory efficiently. The operating system will decide how much memory to assign to particular tasks. It also moves data in and out of memory. 7.Loads and runs software applications. #Command Line Interface's do not make use of images, icons or graphics. All the user is sees is a plain black screen like the one to the right. #Because they use no graphics they require very little computer power. #There are over 270 different commands that can be entered at the command prompt. Commands have to be entered precisely without spelling mistakes or else the operating system will return an error. #Remembering commands and the exact way to enter them can be difficult and so Command Line Interface Operating Systems are considered hard to use. Key features of a Command Line Interface: #The main features of a CLI are that keyboards are used to type in a variety of different commands into a command prompt.
Graphical User Interface (GUI)
An operating system is a software program that manages computer resources. Operating systems allow components to communicate with each other and enables the computer to run software applications. GUI's are visual (graphical) interfaces and they are more popular than CLI's because they are very easy to use. The graphics do need more computer power however.Instead of typing in commands, the user can use a mouse to point and click objects on the screen. 1.Accepts inputs from the mouse 2.Sends outputs to the monitor or printer. 3.Recognises peripheral devices such as external hard disks, pen drive, web cam etc and makes sure that software needed for the hardware to run is installed. 4.Manages files and folders in the system (Naming, Creating, Moving, Finding and Deleting folders etc). 5.Allows applications software (word-processing, spreadsheets etc) to communicate with the system's hardware. Windows The user can divide the screen into separate areas known as 'windows'. These windows can be anything from folders to software applications. Windows allow you to work on several tasks at the same time. Icons Icons are 'symbols' or small images / graphics that are used to represent files and commands. Icons can be clicked to carry out a function or open a file etc. The user operates a mouse to move a pointer over the icon and then clicks it to activate the function.Icons are also used to represent folders. Menus allow users to select functions from a list. Each item in the list will perform a different function.Menus usually either 'pop-up' or 'drop-down'. The navigation used at the top of this web site are examples of drop-down menus. Pointers are little arrows that you move across the screen by directing your mouse. Pointers can be used to select and use icons
impact of emerging technologies on everyday life (e.g. artificial intelligence, vision enhancement, robotics, quantum cryptography, computer-assisted translation, 3D and holographic imaging, virtual reality)
Artificial intelligence This is a computer science that is focused on creating computer systems that simulate human intelligence. Impacts Accurate prediction of weather:AI software will soon be used to sift through weather data more accurately that humans can and will be used to predict approaching storms and automatically issue warnings. Increased leisure time:Robotic vacuum cleaners are becoming more and more popular. These can detect walls and other objects in order to vacuum around them. People can leave them running whilst they enjoy extra spare time. Safer transport: Cars that can self-park already exist and it is predicted that cars that drive themselves will be available soon. These could drastically reduce road accidents.Driverless trains already exist in some countries! Increased Personal safety:Modern home alarm systems use artificial intelligence software that can tell the difference between the home owners and intruders. The software automatically alerts the police when intruders are detected. Improved medical care:Robotic surgery assistants are being used to quickly and accurately pass the correct surgical tools to doctors.The few seconds saved in getting the correct tool to the doctor can save patient's lives.
secondary/backing storage
Backing storage (sometimes known as secondary storage) is the name for all other data storage devices in a computer: hard-drive, etc. Backing storage is usually non-volatile, so it is generally used to store data for a long time.Backing storage devices are slower to access, but can hold data permanently.
impact of biometrics on everyday life
Biometrics is where parts of a person's body are used for identification purposes. Biometrics are beginning to be used in place of passwords and physical locks as a means of security. Biometrics have advantages over these older methods as body parts cannot be lost, forgotten or stolen as can be the case with passwords and keys. Impacts: Better airport security Iris recognition is already in use in some airports. Travelers have their eyes and iris scanned into a system and this data is later matched up when the person is performing airport checks. Increased building security Fingerprint access to buildings have been replacing the older methods of locks and keys. This methods ensures that only authorised people can enter restricted buildings or rooms. Reduced car theft Cars already exist that use fingerprints to only unlock their doors or start the engine for the fingerprint that is registered. This means that the doors will not unlock for a print that is not recognised and makes the car harder to steal. More secure mobile phones Mobile phones contain our lives. We used our phones for everything from social media to shopping online. They need to be as secure as possible in order to protect the valuable data that they contain.
impact of computer-assisted translation in everyday life
CAT is where a human translator uses computer software to help in the translation process..Current CAT tools are not always 100% accurate. They need a human to check for errors. Impacts More accurate documents Spell checkers can quickly scan your word processed documents and automatically find spelling errors.Miss-spelt words can be quickly corrected to produce an error-free document A more multilingual society Anyone with an Internet connection can access tools such as Google Translate and the vast collection of language databases that the tools can search through.This makes accessing other languages much easier than in the past and makes it easier for people to learn these new languages. Quicker and more efficient translations Foreign visitors to countries can be communicated with much easier through these CAT tools.They are especially useful in places like embassies where a wide-range of foreign visitors may need to communicate with local officials about problems or ask for advice etc.
differences between CLI and a GUI
Graphical User Interface (GUI) Advantages: The user does not need to learn any commands. The interface is easier to use. Can use a pointing device to clicks and select icons or menu options. Disadvantages: Takes up more memory than a CLI interface. Requires an operating system to operate. Command Line Interface (CLI) The user has more freedom to use specific command in interacting with the computer. It is possible to alter computer settings. User needs to learn commands Commands must be typed in without errors. No visual aid
input and output devices descriptions
Input devices are pieces of hardware that get raw data into the computer ready for processing.Processing involves taking raw data and turning it into more useful information.Input devices fall into two categories: Manual Input Devices - Need to be operated by a human to input data Automatic Input Devices - Can input data on their own. Output devices When inputted raw data has been processed it becomes usable information. Output devices are pieces of hardware that send this usable information out of the computer.Some output devices send information out temporarily and some send information out permanently: Temporary Output Devices - E.g. Monitors which constantly refresh the outputted image on the screen Permanent Output Devices - E.g. Printers which output information onto paper as a hard copy. An input device sends information to a computer system for processing, and an output device reproduces or displays the results of that processing. Input devices only allow for input of data to a computer and output devices only receive the output of data from another device.Most devices are only input devices or output devices, as they can only accept data input from a user or output data generated by a computer.
describe internal memory, i.e. ROM and RAM and the differences between them
Main memory /internal memory/primary storage is another name for RAM (and ROM). Main memory is used to temporarily store data whilst it is being processed by the CPU. Data can be put into memory, and read back from it, very quickly. Memory is fast to access, but only holds data temporarily... RAM - Random Access memory 1.Contents are lost when the computer is turned off. 2.Stores data and programs currently in use. 3.Your computer will perform faster with more of this. 3.This can be written to (altered) and read from. ROM - Read only memory 1.Contents are not lost when the computer is turned off. 2.Stores instructions that tell the computer how to start up. 3.This cannot be written to (altered).. only read.
define software
Programs that allow the hardware to run properly and allow the user to communicate with the computer
impact of quantum cryptography everyday life
Quantum cryptography (encryption) is an emerging technology that allows messages and data to be sent with complete privacy. Impacts: Completely secure voting Completely secure communication Messages sent by the military often include the locations of squadrons or special op's teams - Using quantum cryptography to secure the messages would eliminate the risk of them being read or heard by unauthorised ears. Completely secure bank transfers Any electronic transfer of money, such as at ATM's or buying goods online, will be completely secure.Some banks are already using quantum cryptography for the purposes of securing money transfers. Completely secure personal information Health records, bank details and other types of personal information will be absolutely secure from hackers and other people wishing to commit identity theft crimes.
impact of robotics on everyday life
Robots are used to perform a wide range of physical tasks.They are either automated (controlled by a computer chip) or manually controlled by a human.There are 4 different types of robots: Manufacturing robots (used to perform rpetitive tasks such as welding) Carrier robots (used by the military to carry heavy loads over dangerous terrain) Domestic robots (used in homes to perform cleaning tasks such as vacuuming) Exploration robots (used to visit and send images from places such as Mars) Impacts: Increased personal time If robots can carry out domestic chores, this frees up more time for us to spend as we wish. This could mean more time spent at work or for more enjoyable activities such as socialising. More efficient manufacturing Robots can manufacturer products such as cars much faster and cheaper than humans can. This means that companies can make more products at less cost and this means greater business profits. Loss of jobs Due to higher and cheaper productivity, robots are taking over the manufacturing jobs that used to be carried out by humans. This means that humans are missing out on employment on assembly lines and factory work. Safer working environments Robots can safely carry out tasks that are too dangerous for humans.For example: spraying cars with toxic paint, defusing bombs on battlefields and search and rescue operations in buildings destroyed by earthquakes.
impact of 3D and holographic imaging
This is a technique where images are made to appear three-dimensional and to actually have depth.Holograms work by taking two regular two-dimensional images of the same object and laying one on top of the other.Two different types of laser beams are used to record the two-dimensional images onto a single photographic plate.When viewing the image, human eyes see it from slightly different angles. The brain combines them into a three-dimensional image. Impacts: Improved security Credit cards, ID cards, software and some bank notes include holograms as a way of trying to prevent forged duplicates being created. Better movie experiences Hollywood have been using 3D imaging within the production of movies for many years. These provide the viewer with a much more immersive experience. Greater data storage It is thought that the technology behind holograms will eventually be used to provide the means to store large amounts of data. Companies have already produced discs that use holographic layers that each have the potential to hold a massive 3.9 terabytes.
impact of virtual reality on everyday life
Virtual reality is where computers are used to create an artificial environment that users can interact with as if it were real.Virtual reality is not really meant for gaming purposes. It is used for more serious purposes such as: Allowing architects to walk around a virtual version of their design (this gives a better idea of what the finished building will look like) Training soldiers in combat (flight simulation, battlefield simulation) Training surgeons (virtual patients can be operated on to provide experience to trainee surgeons). Virtual reality is still a developing technology and graphics produced are not very realistic yet. However, experiences in the virtual environment can seem very real. Equipment: Eye Goggles -These produce the 3D images that make up the artificial world.The goggles project slightly different views into each eye and this fools your brain into thinking that the scene is 3D. Virtual chairs look solid and so on. Special Gloves -The gloves detect your hand and finger movements which are input into a computer and processed. As users touch or use items in the virtual world, the computer can carry out these commands and make them happen. This allows the user to interact with the virtual world and perform tasks such as moving objects or switching on lights etc. Headphones -These control what users hear in the virtual world. Computer -A very powerful computer is needed to create the virtual environment and to process/output data sent into the system by the user's actions. Impacts: Improved medical surgeons Surgeons can be trained using virtual patients. This allows them to practice over and over until they have perfected a particular surgery without risk to a real patient. Larger and stronger buildings Virtual buildings allow architects to walk around to experience what the building would look like when completed and check for potential errors before the actual building is constructed.Virtual buildings will also be able to be tested against factors such as earthquakes to see what effects they would have on the current design. This allows architects to modify designs quickly and cheaply and will, potentially, allow for the development of much larger and safer buildings than we currently have. More effective treatment of phobias VR is being used to help patients overcome phobias and anxieties. People can experience a tame, controlled version of what they are afraid of. Slowly the person becomes used to the situation and can relax. Training in dangerous situations VR can be used for training in dangerous situations where it is impossible to practice the real thing. More realistic education VR can give students the opportunity to learn in a much more interactive way.This approach is likely to allow students to retain knowledge much better than reading text out of a book.
two types of software
• applications software • system software
examples of system software
• compilers • linkers • device drivers • operating systems • utilities
external hardware devices and peripherals
• monitors • keyboards • mice • keyboards • printers as input and output devices • external storage devices in general Almost all input and output devices are known as 'Peripheral devices'.
internal hardware devices
• processor • motherboards • random access memory (RAM) • read-only memory (ROM) • video cards • sound cards • internal hard disk drives
applications software
• word processing • spreadsheet • database management systems • control software • measuring software • applets and apps • photo-editing software • video-editing software • graphics manipulation software