Hardware :MAB 2005 - 2006 Hardware Hardware is the term used for the physical components that make up a computer system If you can touch it – it’s hardware Hardware includes Input devices The processor Output devices We will concentrate on input and output devices


Input Devices :MAB 2005 - 2006 Input Devices The purpose of these devices is to get data into the computer The ideal input device would input the data automatically without any human intervention, accurately and quickly and have a low cost Unfortunately, such a device does not exist Therefore a compromise has to be made depending on the type of application the device is to be used for Make a list of as many input devices you can think of


Input Devices :MAB 2005 - 2006 Input Devices 2 Scanner 4 Bar Code Reader 1 Optical Character Recognition 1 Optical Mark Reader 1 Magnetic Ink Character Reader 3 Touch Screen 3 Graphics Tablet 3 Keyboard 4 Tracker Ball 4 Light Pen 2 Magnetic Stripe Reader 2 Punched Card Reader For each device- Provide a description of how it works using suitable images Explain an area of application it may be used in You have 45 mins for this task


Optical Character Recognition :MAB 2005 - 2006 Optical Character Recognition Uses a scanner in combination with a special piece of software that is able to recognise individual characters that have been scanned Light is shone onto the page to be read, and the level of light that is reflected is measured by the software More reflection will come from white than black, therefore the ‘shape’ of the scanned character can be seen The software uses ‘matrix matching’ to compare this shape with those stored in the program The character that has the closest match to the shape is then chosen


Optical Character Recognition :MAB 2005 - 2006 Optical Character Recognition Public and Private Parking Management   Automatic Toll Collection Border Control General Traffic Enforcement Stolen Car Search


Optical Character Recognition :MAB 2005 - 2006 Optical Character Recognition


Optical Character Recognition :MAB 2005 - 2006 Optical Character Recognition Other areas of use are Scanning in applications for driving licenses/passports Scanning in customer readings for gas/electricity


Optical Character Recognition :MAB 2005 - 2006 Optical Character Recognition A main advantage of OCR is that it is significantly faster than typing, however it is not completely accurate, and text would need proof-reading afterwards You would also incur the cost of a scanner and the software, which is more expensive than simply entering the data at a keyboard


Optical Mark Reader :MAB 2005 - 2006 Optical Mark Reader These devices are designed to read marks made on specially designed documents Again they use the principle of reflected light to determine if a mark has been made in a specific area or not OMR is an extremely quick and efficient way of entering data into a system


Optical Mark Reader :MAB 2005 - 2006 Optical Mark Reader Optical Mark Recognition may be used for many different applications such as Multiple choice exams National Lottery The main problem is that the sheets may be ripped or folded, and the marks are not always made within the area indicated Sometimes the sheet may be rejected if it cannot be read successfully Also a lot of marks are required to capture a small amount of data


Mouse - Example :MAB 2005 - 2006 Mouse - Example Mouse http://sloan.stanford.edu/mousesite/1968Demo.html


Magnetic Ink Character Reader (MICR) :MAB 2005 - 2006 Magnetic Ink Character Reader (MICR) These are expensive input devices that are used to read characters written in special magnetic ink (which contains iron oxide) usually on bank cheques As the document passes into the MICR device, the ink is magnetised, so that the shapes of the characters can be recognised electronically


Magnetic Ink Character Reader (MICR) :MAB 2005 - 2006 Magnetic Ink Character Reader (MICR) The characters used are highly stylised and in the UK, there are only 14 in the entire character set The main advantage is that it is very difficult to forge because of the unique shape and construction of the numbers Also should the MICR device fail then the data can still be entered as the characters can be read by a human Even if the document is ripped, folded or even has a drink spilt on it, the device will still be able to read it correctly It is a much quicker of entering details than via a keyboard The main disadvantage is the cost of the MICR equipment and the magnetic ink used


Bar Code Reader :MAB 2005 - 2006 Bar Code Reader Once again a device that uses the reflection of light to identify the absence or presence of a mark The thickness of the black lines in a bar code determines the value of the number the line represents Bar code readers are generally used in shops to identify a product, but they may be used any any system where an identifying number needs to be read The Learning Curve uses such a system to identify students when they loan books – indeed the books themselves use bar codes too


Bar Code Reader – EPOS (how bar codes work in the supermarket) :MAB 2005 - 2006 Bar Code Reader – EPOS (how bar codes work in the supermarket) The bar code is scanned and the relevant code is sent to the product database which is generally stored on a computer within the supermarket This code is then looked up in the database and a product description and price is returned to the checkout These details are then displayed on the checkout and printed on a receipt for the customer


Bar Code Reader :MAB 2005 - 2006 Bar Code Reader We have already looked at supermarkets and libraries, but barcodes can be used in many more ways: Tracking parcels Luggage handling in an airport Patient/Medicine identification in a hospital Stock control in a warehouse Barcodes do not contain the price or the sell by date of the product They do contain however, details of the country of origin, manufacturer, name of product etc Barcodes make use of a check digit to ensure their accuracy The check digit is always the final number on the barcode and can be used to see if the barcode was scanned correctly If the barcode is not scanned correctly, the dreaded BEEP occurs!


Check Digits :MAB 2005 - 2006 Check Digits Using the standard 13 digit bar code found on most items- Starting from the left place a weighting of 1 then 3 then 1 etc, over the top of each number, excluding the last one (as that is already the check digit) Original barcode without check digit Then multiply each digit with the weighting above it to get 9+21+8+0+7+12+8+21+3+18+0+27=134 The answer must be evenly divisible by 10, if it is, divide by 10 and that is the check digit. If it isn’t the number you have to add to make it evenly divisible by 10 is the check digit 134 + 6 = 140, which is divisible by 10, therefore 6 is the check digit


Check Digits :MAB 2005 - 2006 Check Digits Lets try it with another book


Bar Code Fun :MAB 2005 - 2006 Bar Code Fun http://www.barcodeart.com/art/yourself/yourself.html


Punched Card Reader :MAB 2005 - 2006 Punched Card Reader Made of thin cardboard, the punch card represents information by the presence or absence of holes in predefined positions on the card In the first generation of computing, from the 1920s into the 1950s, punch cards were the primary medium for data storage and processing Eventually, during the late 1970s to early 1980s, the punch card was phased out as a medium for storage of computer data and replaced by huge floppy disks


Magnetic Stripe Reader :MAB 2005 - 2006 Magnetic Stripe Reader A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card The magnetic stripe, sometimes called a magstripe, is read by physical contact and swiping past a reading head Magnetic stripe cards are commonly used in credit / debit cards, identity cards even security systems


Magnetic Stripe Reader :MAB 2005 - 2006 Magnetic Stripe Reader Many hotels are now using these types of locks on room doors as opposed to the traditional key lock Entry is gained by swiping the card through the card reader Why do you think that the systems are becoming more popular?


Smart Cards :MAB 2005 - 2006 Smart Cards As technology develops, new methods of storing data are becoming popular Smart cards are now replacing magnetic stripe cards (which have become easy to copy by criminals) A smart card resembles a credit card in size and shape, but inside it is completely different First of all, it has an inside, a normal credit card is a simple piece of plastic The inside of a smart card usually contains an embedded microprocessor The microprocessor is under a gold contact pad on one side of the card Think of the microprocessor as replacing the usual magnetic stripe on a credit card or debit card


Smart Cards :MAB 2005 - 2006 Smart Cards Smart cards are much more popular in the rest of Europe than in the UK In Europe, the health insurance and banking industries use smart cards extensively Every German citizen has a smart card for health insurance Even though smart cards have been around in their modern form for at least a decade, they are just starting to take off in the UK Magnetic stripe technology remains in wide use in the UK, however, the data on the stripe can easily be read, written, deleted or changed with off-the-shelf equipment – therefore not very safe


Scanner :MAB 2005 - 2006 Scanner In computing, a scanner is a device that analyses a physical image (such as a photograph, printed text, or handwriting) or an object (such as an ornament) and converts it to a digital image Most scanners today are variations of the desktop (or flatbed) scanner Hand-held scanners, where the device is moved by hand, were briefly popular but are now not used due to the difficulty of obtaining a high-quality image Scanners are generally used in conjunction with OCR software


Touch Screen :MAB 2005 - 2006 Touch Screen A touch screen is a screen through which data can be input just by touching it with a finger Items are selected just as they would be with a mouse pointer or a light pen The system consists of a normal glass panel that is covered with a conductive and a resistive metallic layer. These two layers are held apart by spacers, and a scratch-resistant layer is placed on top of the whole setup. An electrical current runs through the two layers while the monitor is operational. When a user touches the screen, the two layers make contact in that exact spot. The change in the electrical field is noted and the coordinates of the point of contact are calculated by the computer. Once the coordinates are known, a special driver translates the touch into something that the operating system can understand, much as a computer mouse driver translates a mouse's movements into a click or a drag


Touch Screen :MAB 2005 - 2006 Touch Screen Popular areas of application are Information kiosks (tourist board) Satellite navigation systems Checkouts (McDonalds) Ticket machines


Light Pen :MAB 2005 - 2006 Light Pen A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with the computer's CRT monitor It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy A light pen can work with any CRT-based monitor, but not with LCD screens, projectors or other display devices.


Graphics Tablet :MAB 2005 - 2006 Graphics Tablet A graphics tablet is a computer peripheral device that allows one to hand-draw images directly into a computer, generally through an imaging program Graphics tablets consist of a flat surface upon which the user may "draw" an image using an attached stylus, a pen-like drawing apparatus The image generally does not appear on the tablet itself but, rather, is displayed on the computer monitor. Allows the user to draw or trace complicated images with greater accuracy than a mouse Often used by graphical artists


Trackball :MAB 2005 - 2006 Trackball A trackball is a pointing device consisting of a ball housed in a socket containing sensors to detect rotation of the ball about two axes—like an upside-down mouse, but with the ball sticking out more The user rolls the ball with their thumb, fingers, or the palm of their hand to move a cursor


Trackball :MAB 2005 - 2006 Trackball Tracker balls are common on CAD workstations for ease of use and, before the advent of the touchpad, on portable computers, where there may be no desk space on which to use a mouse Trackballs are sometimes seen on computerised special-purpose workstations, such as the radar consoles in an air-traffic control room or sonar equipment on a ship or submarine Trackballs were often used in early arcade games as a method of controlling the player/spaceship etc


Keyboard :MAB 2005 - 2006 Keyboard A computer keyboard is a peripheral modelled after the typewriter keyboard Keyboards are designed for the input of text and characters, and also to control the operation of the computer Physically, computer keyboards are an arrangement of rectangular or near- rectangular buttons, or "keys“ Keyboards typically have characters engraved or printed on the keys; in most cases, each press of a key corresponds to a single written symbol However, to produce some symbols requires pressing and holding several keys simultaneously, or in sequence; other keys do not produce any symbol, but instead affect the operation of the computer, or the keyboard itself


Keyboard :MAB 2005 - 2006 Keyboard


Keyboard :MAB 2005 - 2006 Keyboard The keyboard is still the most popular input device and is available in a variety of different styles to suit various users


Processing Devices :MAB 2005 - 2006 Processing Devices The processor is the name given to the chip that performs all arithmetic and logic operations It may be thought of as the engine of the computer, as without it, the system would not work It used to be the case that the computers we had at home had a single processor in them – only expensive mainframe computers would have two processors However, recently Intel have introduced Dual-Core technology that is effectively two processors on the motherboard Demo


Storage Devices :MAB 2005 - 2006 Storage Devices There are many different storage devices on the market and we will look at nine of them Fill in the table you have been given with the necessary information This will act as a good revision sheet for the exams You have 40 mins for this task


Storage Devices :MAB 2005 - 2006 Storage Devices Provide details for the following storage devices Hard drives DAT drive (digital audio tape) Zip drives CD-ROM CD – R CD - RW DVD drive RAID (redundant array of inexpensive disks)


Floppy Disks :MAB 2005 - 2006 Floppy Disks Floppy disks, also known as floppies or diskettes (a name chosen in order to be similar to the word "cassette"), were popular in the 1980s and 1990s, being used on home and personal computer ("PC") platforms such as the Apple Macintosh, Commodore 64, Amiga, and IBM PC to distribute software, transfer data between computers, and create small backups Before the popularisation of the hard drive for PCs, floppy disks were often used to store a computer's operating system (OS), application software, and other data.


Floppy Disks :MAB 2005 - 2006 Floppy Disks Before the standard 3.5 inch floppy disks that are most common, we had 8 inch then 5.25 inch versions


Floppy Disks :MAB 2005 - 2006 Floppy Disks Write-protect tab Hub Shutter Plastic housing Paper ring Magnetic disk Disk sector


Hard Drives :MAB 2005 - 2006 Hard Drives Hard disks were invented in the 1950s They started as large disks up to 20 inches in diameter holding just a few megabytes They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks" Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies Hard disks have the major benefit of magnetic storage -- the magnetic medium can be easily erased and rewritten, and it will "remember" the magnetic flux patterns stored onto the medium for many years


Hard Drives :MAB 2005 - 2006 Hard Drives The platters - These typically spin at 3,600 or 7,200 rpm when the drive is operating. These platters are manufactured to amazing tolerances and are mirror-smooth The arm - This holds the read/write heads and is controlled by the mechanism in the upper-left corner. The arm is able to move the heads from the hub to the edge of the drive. The arm and its movement mechanism are extremely light and fast. The arm on a typical hard-disk drive can move from hub to edge and back up to 50 times per second -- it is an amazing thing to watch!


Hard Drives :MAB 2005 - 2006 Hard Drives Advantages over floppy disks : Access to data is faster than from floppy disks. Hard discs store more data than floppy disks They are more reliable than floppy disks as they have more protection from dirt.   One disadvantage of a hard disc over floppy disk is that it is not portable – you cannot carry it round and use it on different computers However you can buy external hard disks


Zip Drives :MAB 2005 - 2006 Zip Drives These are cheap storage devices that plug into the parallel port of a computer They consist of a single removable disk of the same diameter as a 3.5 floppy that also looks like a floppy disk, but just a bit fatter


Zip Drives :MAB 2005 - 2006 Zip Drives Typical storage capacities are around 100 – 250 mb They are ideal for backup purposes as they hold a lot of data but are portable and removable They are also a lot more robust and durable than a floppy disk


CD – ROM (Read Only Memory) :MAB 2005 - 2006 CD – ROM (Read Only Memory) CD ROM disks are the best medium for distribution of software because of their high storage capacity Typically this is 640 Mb Rather than using numerous floppy disks, a CD ROM can hold all the data required for an application on one disk There are many different CD ROM drives available with a variety of speeds that they operate at 40-speed, 48-speed, 50-speed refers to the speed at which the CD is able to transfer its data CD ROM disks are written by the manufacturer of the software Users cannot alter the data that is contained upon them


CD- R and CD - RW :MAB 2005 - 2006 CD- R and CD - RW CD-R drives use disks that can be written to once, but never again They can however be read as many times as you like These are often called WORM disks – can you guess why? CD-RW disks are read/write which means the information written onto them but can also be overwritten with new information An obvious advantage is that they can be used time and time again, However as the information is burned onto the disk by a laser, the surface of the disk will gradually deteriorate and eventually the disk will not function properly


DAT drive :MAB 2005 - 2006 DAT drive These can be external or internal drives and are mainly used for backup purposes They store between 2 and 40 Gb of data, which is why they are popular as a backup medium They are reasonably cheap and are able to store large amounts of data on one tape However they do need to have the tape heads cleaned regularly and they tapes is easily damaged


DVD Drive :MAB 2005 - 2006 DVD Drive DVD (sometimes known as "Digital Versatile Disc" or "Digital Video Disc") is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality DVDs resemble compact discs as their physical dimensions are the same (12 cm or occasionally 8 cm in diameter) but they are encoded in a different format and at a much higher density Although we tend to assume that DVDs are used to store films on, they are simply a disk which can hold data, no matter what the data is Therefore this PowerPoint file could just as easily be stored on a DVD as a CD


DVD Drive - Films :MAB 2005 - 2006 DVD Drive - Films Each DVD-Video disc contains one or more region codes (denoting the area(s) of the world in which distribution and playback are intended The commercial DVD-Video player specification dictates that a player must only play discs that contain its region code In theory, this allows the motion picture studios to control the various aspects of a release (including content, date and price) on a region-by-region basis In practice, many DVD players allow playback of any disc, or can be modified to do so.


RAID (Redundant Array of Inexpensive Disks) :MAB 2005 - 2006 RAID (Redundant Array of Inexpensive Disks) Mostly used on a computer network The RAID server is made up of a series of high capacity hard disks that are written to and read from as a normal hard disk would be The difference here is that they all have the same data written to and read from them at the same time, so that if one disk fails, the data can still be retrieved from or stored on another of the disks


RAID (Redundant Array of Inexpensive Disks) :MAB 2005 - 2006 RAID (Redundant Array of Inexpensive Disks) Do not be fooled by the fact that they are called inexpensive disks, the entire server including all the disks is very costly However the cost is a small price to pay for the knowledge that your data is safe and secure There is very little chance that all the disks will fail at the same time and when one does it is replaced immediately This server has 35 250Gb disks contained within it, which offers a storage solution that is more than enough for most medium to large businesses


Output Devices :MAB 2005 - 2006 Output Devices The purpose of output devices is to produce the information that the computer has processed in a form that the user can make use of The form the information is in depends on the output device which is used Make a list of as many output devices as you can – you may find it harder than the input device list you did last lesson


Printers :MAB 2005 - 2006 Printers Factors affecting choice Volume of output High volume require fast, heavy-duty printer Quality of print required Location of printer Are multiple copies required? Is colour required?


Types of Printer :MAB 2005 - 2006 Types of Printer Dot Matrix Impact Printer - Print head has 9 or 24 pins Pins strike paper through a ribbon. 24 pins give better print quality – dots closer NLQ (Near Letter Quality) obtained by printing each line twice, which second pass slightly displaced so as to fill any spaces. Printers are often bi-directional Very versatile Colour possible via 4-colour ribbon – but quality not too good Can be very noisy


Types of Printer :MAB 2005 - 2006 Types of Printer Inkjet Printer Very popular – often bundled with PC Cheap with very good resolution, particularly on special papers Droplets of ink are fired at the paper Large areas of colour may get the page too wet unless special paper is used Colour printing can be quite expensive


Types of Printer :MAB 2005 - 2006 Types of Printer Laser Printer More accessible now as prices come down Similar process to photocopier with toner images being fused onto the paper by heat and pressure Very high quality Virtually silent Colour option can be very expensive


Printers Activity :MAB 2005 - 2006 Printers Activity A home user who prints one or two pages a month from the internet but otherwise will need a printer for producing letters A home user who prints photographs from their digital camera A small publishing company A mail order company For each of the different users listed above research the most suitable printers currently available stating which printer you think would be best for each user and why In your research consider and provide details for Purchase cost Speed of print Cost of consumables (print ribbon or cartridge) Resolution (quality) of print Each of these considerations will help you in choosing the most appropriate printer You have 30 mins for this task


Plotters :MAB 2005 - 2006 Plotters Used for high quality line drawings Building plans Circuit diagrams Pen (Vector plotters) Draw images using point-to-point data, moving pen over the paper. Low in price Penless (Raster plotters) Electrostatic, thermal or laser plotters Required for high-density images Maps Assemble drawings for machines


Plotters :MAB 2005 - 2006 Plotters


VDU :MAB 2005 - 2006 VDU Monitors are obviously the most popular output device and are used in nearly all applications Monitors come in many sizes, however the standard 14 inch screen has now been replaced by a 15 inch version and 17, 19 and 21 inch monitors are also available Early monitors for home computers were actually TVs! Just like you use the TV for playing Playstation and Xbox games now, you could connect your ZX Spectrum to the television and use your computer Commodore 64 computers actually had their very own monitor – a rare peripheral 25 years ago!


VDU :MAB 2005 - 2006 VDU


VDU :MAB 2005 - 2006 VDU As well as the size of the screen, another major consideration when choosing a monitor is its resolution This is basically a measure of the quality of the picture on the screen, the higher the resolution the better quality the picture Images on a screen are made up of pixels which are tiny dots of different colours similar to the dots that made up the characters printed by a dot matrix printer


VDU :MAB 2005 - 2006 VDU This image is displayed in two different resolutions The image on the left is 800 x 600 pixels in size which means the entire image is made up of 480000 pixels The image on the right is 1024 x 768 pixels in size, which means the image is made up of 786432 pixels As you can the image on the right is better quality because it contains more pixels


Speakers :MAB 2005 - 2006 Speakers Speakers require a sound card within the computer in order to operate Up until the mid 1980s users had to make to with the internal speaker of the computer, which was very poor quality When sound cards were first introduced around 1986 users where able to attach these cards to the motherboard of their computer and plug speakers into the sound card