Computer Hardware docx

Computer Hardware Hardware and Software • Hardware refers to all the parts of the Computer System that we can touch Examples of hardware are monitors, joysticks, printers, processors etc • Software refers to all the programs and data that we use with the computer What is a Computer? • A computer is an information processing machine • A computer only follows the instructions it is given • Data is Input, Processed and then Output I’m ONLY a machine! Sizes of Computers • Microprocessor Smallest » A small chip programmed with instructions • Microcomputer » The most common type of computer The IBM PC is a microcomputer • Mini Computer » Medium to Large computers - mainly used to process business information • Mainframe Computer » Very powerful computers able to process 1000’s of times more information a second than PCs Biggest IPO - Input, Process, Output INPUT PROCESS OUTPUT Data is INPUT into the computer system It is then PROCESSED to produce useful Information as OUTPUT Data and Information Data has no meaning • Data is made up of symbols e.g 871652; H789 IOS; £76.91 Information has a meaning • We understand what a piece of information is about e.g Telephone Number: 871652 Car License Plate: H789 IOS More Input, Process, Output • Data is the RAW MATERIAL • This raw material is processed • When the processing is completed a useful thing is produced…INFORMATION • Voice Recognition With voice recognition systems the computer can understand the words spoken to it and can carry out commands associated with the words Using voice recognition a letter can be dictated instead of being typed at the keyboard • Handwriting Recognition Handwriting can be recognised and the computer can convert the written text into typed text for storing Optical Character Recognition • OCR Is used to convert paper typed documents into text files that can be edited and stored on a computer system OCR software can search a scanned image for the shapes of letters, numbers etc When it finds shapes that match it converts them to the correct text and stores them in a file Types of Output • Plotter A plotter is a device used for creating a hard copy of the output from a computer system Plotters use special pens to draw the output as a series of lines Plotters are often used to output building drawings and designs • VDU or Monitor Visual Display Unit (VDU) is the proper name for the computer monitor The VDU allows us to see the output from the computer Monitor - Visual Display Unit • A monitor or VDU is an output device that can display graphics and text and video • The picture on a monitor is made up of thousands of tiny coloured dots called pixels • The quality of the output on a monitor depends on its resolution • The resolution of a monitor depends on the number of pixels that it can display More on Output Devices • There are three types of printers – laser – inkjet – dot-matrix • Printers are used to create a hard copy of output from the computer system (normally on paper) Laser printers are expensive, produce high quality printouts, can produce to 12 pages in a minute and are almost silent when they are working More on Output Devices • Inkjet printers are cheaper than laser printers, they produce reasonable quality printouts (not quite as good as laser), can also printout in colour, can print to pages in minute but there are a little noisy • Dot-matrix printers are the cheapest, they produce poor quality printouts, some can print in colour, they struggle to print page in a minute and they are VERY noisy More on Output Devices • Voice Output Voice output from a computer system is also known as speech synthesis Some voice output programs are know as text readers They take a text file and recite it to the user Hello, I am Hal! Other speech synthesis programs can tell the user what they are doing (for example floor announcements in a speaking elevator) Types of Media • Media is the material used in devices • Examples of media are Floppy disc and CD-ROM • If CD-ROM is the MEDIA then the CDROM drive is the DEVICE Multimedia • Multimedia systems combine graphics, text, sound, video and animation to provide a rich experience for the user • Many interactive multimedia software titles are available now • Often these are stored on CD-ROM e.g Microsoft Encarta Virtual Reality • Virtual Reality involves the user entering a 3D world generated by the computer • To be immersed in a 3D VR world requires special hardware e.g • A headset (containing goggles, headphones and a position tracker) • A data glove or data suit so that the users body can interact with the VR world What is a Computer System ?  A computer system is a collection of parts that work together  A standalone computer system is a computer system that is NOT connected to other computers  It consists of at least one input device, a processor and one output device A Computer System ? MonitorOutput PrinterCentral Processing Unit Output Mouse- Keyboard- Input Input Computer Networks • A network is made up of two or more computers linked together Advantages are: * Share devices between computers * Share data between computers * Share programs between computers * Saves time A Typical Local Area Network • A local area network is a computer network across one building or site Printer Work Station Fileserver Network Cable ... machine! Sizes of Computers • Microprocessor Smallest » A small chip programmed with instructions • Microcomputer » The most common type of computer The IBM PC is a microcomputer • Mini Computer » Medium... refers to all the programs and data that we use with the computer What is a Computer? • A computer is an information processing machine • A computer only follows the instructions it is given • Data... Hardware and Software • Hardware refers to all the parts of the Computer System that we can touch Examples of hardware are monitors, joysticks, printers,