Transcript Chapter 3
Chapter 3 Introduction to Personal Computers in the Classroom Presented by Ricky Broussard ETEC 562 – Spring 2004 What we should learn from this Chapter • Identify the key components of a computer system • Explain the role of input devices and describe the features of the most common types • Explain the role of and describe the features of the most common types of output devices • Describe the relationship and function of the central processing unit, memory, and storage • Describe the functions and purpose of and the most common types of storage devices How Does a Computer Work? “Computing Cycle” Storage Input Devices Central Processing Unit Memory Output Devices What Happens When I Turn it On? Power ON Read Data from ROM Run Post Power On Self Test A self diagnostic that ensures Is everything OS Loads all basic components YES NO Process Stops OK? on the computer are functioning correctly – A good POST results in a Single Beep Components of a Computer System • Hardware – includes all the physical, touchable pieces or equipment – modem, monitor, hard drive, etc. • Software – programs, or sets of computer instructions, that tell the Hardware how to perform a specific task – Operating System, Word, Excel, Quicken, etc. Hardware • Can be broken down into 5 categories System Components Memory Storage Input Devices Output Devices System Components • Motherboard – Houses most major internal components – Provides arteries or “buses” for transmission of information from component to component • CPU- Central Processing Unit – The “BRAINS” of you computer – Performs mathematical calculations – Coordinates communications between computer’s components • Power Supply and Case Memory • ROM – Read Only Memory – BIOS (Basic Input/Output System)Provides basic boot-up instructions that allow components to talk to CPU prior to OS (Operating System) loading – Requires special equipment and processes to alter – Located on motherboard http://www.hardware-one.com/reviews/abitgf256/images/bios.jpg Memory • RAM – Random Access Memory – Temporary memory storage that can be accessed by software and hardware – Common Types • SRAM – static – Faster and does not need to be constantly refreshed – Expensive – Generally used as system cache in CPU • DRAM – dynamic – Must constantly be refreshed – Cheaper – Most commonly used form of system memory Storage • Hard Drive - Primary storage device – Data is stored on a series of metal platters mounted inside housing – Data is stored electro-magnetically – Currently capacity is measured in Gigabytes, or billions of bytes – 1 byte = one alphabetic or numeric character – Primary Drive or Bootable Drive generally holds your Operating System • Floppy Drive – Data is stored on flexible film with a magnetically sensitive coating – Cheap – Most common source of virus transmission Storage • CD Drives – Optical technology that “burns” pits and valleys onto tracks on the surface of the disk – CD-ROM: read only disk – most common usage is application delivery and music storage – CD-R: allows User a one-time option to create their own CD-ROMs – CR-RW: a re-usable CD that can be rewritten, functioning much like a Hard Drive – Stores up to 700 MB or 80 minutes How Optical Drives work Storage • DVD Drives (Digital Versatile Disk) – An emerging optical technology that stores up to 17.5 gigabytes of data – Disc is recordable on both sides and stores data in 2 layers on each side – DVD drives can read CD, CD-R,and CD-RW – Writeable versions with a capacity of 4.75 GBs are now commercially available Input Devices • Most common – Keyboard – Mouse • Other – – – – Trackball Joystick Touchpad Scanner Monitor – Output Device • CRT – Cathode Ray Tube Most common form of monitor cheap • LCD – Liquid Crystal Display “flat screen” technology Expensive but better quality picture • Quality Pixel – a single colored dot Resolution – refers to clarity and crispness of image Standard resolution is 640 x 480 Screen Size – number of inches measured diagonally across the screen Printers –Output Device • Provide hard copy • What to look for is a printer – Color output - black-and-white printing, or color printing. – Speed - pages per minute (ppm) – Image resolution - dpi (dots per inch) - resolution determines the amount of detail the printer can reproduce – Output size – what is largest output area? – Printer size - the size of the printer unit Inkjet Printers • Use a thermal process to eject ink via print mechanism onto paper – ink is actually heated until it boils • Electrically charged plates deflect ink onto paper • 300 to 600 nozzles • Paper moves via friction feed mechanism Laser Printers/ Copiers • Traditionally use a photoconductive process • Image is written on drum in printer and then transferred to paper by using opposing electrical charges • Toner is composed of plastic particles and iron-oxide • Image is fused on paper • New versions use wax instead of toner Lets not forget Software • Operating System – interface between User and Hardware • GUI – Graphic User Interface – uses icon and window based interface to allow user to more easily navigate and control OS • 2 most popular Windows Apple • Applications/Programs Allows user to perform task specific activities on the computer Conclusion • A computer is merely one of many tools available to enhance the education process • Familiarity will breed confidence – Get to know your equipment • Don’t be afraid to ask for help (even from the kids!) 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