COMPUTERS IN THE CLASSROOM CT 243

15. CHAPTER 4 Hardware Applicationsfor Educators

16. Objectives Describe the system unit Define a bit and describe how a series of bits are used to represent data Identify the major components of the system unit and explain their functions Explain how the CPU use the four steps of a machine cycle to process data Describe the four types of input and input devices List the characteristics of a keyboard and identify the various types of keyboards Identify various types of pointing devices

17. Objectives continued Differentiate between the four different types of output Identify the different types of output devices Explain the difference among various types of printers Differentiate between storage and memory Identify types of storage media and devices Explain how data is stored on floppy and hard disks Differentiate between CD-ROMS and DVD-ROMS

18. System unit and data representation System unit is a box-like case that houses the electronic components a computer uses to process data Analog - continuous electrical wave Digital - representation of data using two discrete states: on and off Byte - when eight bits of data are grouped together ASCII - American Standard Code for Information Interchange

19. Components of a system unit Motherboard - circuit board in the computer that contains many of the electronic components in the system unit Central processing unit CPU - electronic device on the motherboard that interprets and carries out the instructions that operate the computer Control unit - component of the CPU that directs and coordinates most of the operations of the computer Fetching - obtaining program data or instructions Decoding - process of translating instructions into commands Executing - process of carrying out commands Storing - process of writing results to memory Machine cycle - four instructions together

20. Components of a System Unit Continued Arithmetic/logic unit - CPU component that performs the execution part of the machine cycle Arithmetic operations - include addition, subtraction, multiplication, and division Comparison operations - involve comparing one data item to another to determine if the the first item is greater than, equal to, or less than the other Logical operations - work with conditions and logical operators such as AND, OR, and NOT

21. Components of a System Unit Continued System clock - small chip that synchronizes, or controls the timing of, all computer operations Clock speed - speed at which a processor executes instructions I.e. - 933 Mhz - nine hundred, thirty-three million clock cycles, or ticks, in one second Memory - location in the computer to store data and instruction I.e. - 1 GB is equal to one billion bytes of data Address - unique number identifying the location of a byte in memory

22. Components of a System Unit Continued Random access memory (RAM) - volatile memory in which its contents are lost (erased) when a computer�s power is turned off I.e. - 64, 128, 256 Mb RAM/SDRAM Read only memory (ROM) - devices are chips that store information or instructions that do not change. (I.e. - operating system) Expansion slot - is an opening, or socket, where a circuit board can be inserted into the motherboard Plug and play - computer�s capability to configure automatically expansion cards and other devices as they are installed PC card - special type of expansion card for notebook and other mobile computers

24. PICTURES ON PAGE 4.11

25. Components of a System Unit Continued Port - is the point attachment to the system unit and most computers contain ports on the back of the system unit Universal Serial Bus (USB) - can connect up to 127 different peripheral devices with a single connector type Firewire (1394) port - can connect multiple devices that require faster data transmission speeds, such as digital video cameras

26. Input Input - is any item you enter into the memory of a computer Data - is a collection of unorganized facts that can include words, numbers, pictures, sounds, and so on Program - is a series of instructions that tells a computer how to perform the tasks necessary to process data into information Command - is an instruction given to a computer program Keyword - is a special word, phrase, or code that a program understands as an instruction User response - answer to a question asked by a program

27. Input Devices Keyboard - is a group of switches resembling the keys on a typewriter that allows users to enter input Numeric keyboard - is a calculator-style arrangement of keys representing numbers, a decimal point, and some basic mathematical operators Wireless keyboard - is a battery operated device that transmits data using wireless technology, such as radio waves or infrared light waves

28. Input Devices Continued Pointing device - is an input device that allows you to control a pointer on the screen Mouse - is the most widely used pointing device, because it takes full advantage of a graphical user interface Optical mouse - has no moving parts, instead it uses devices that emit and sense light to detect the mouse�s movement Wireless mouse - is a battery powered device that transmits data using wireless technology, such as radio waves or infrared waves

29. Input Devices Continued Touchpad - is a small, flat, rectangular pointing device that is sensitive to pressure and motion. Pointing stick - is a pressure-sensitive pointing device shaped like a pencil eraser Trackball - is a stationary pointing device with a ball mechanism on its top Joystick - is a vertical lever mounted on a base. Touchscreen - a monitor that has a touch sensitive panel on the screen, used for input Optical reader - is a device that reads characters, marks, and codes and then converts them to digital data that can be processed by a computer 3 types OCR, OMR, Bar Scan

30. Input Devices Continued Optical scanner - is an input device that electronically can capture an entire page of text or images such as photographs or artwork Digital camera - allows you to take pictures and store the photographed images digitally instead of on traditional film Audio input - is the process of recording music, speech, or sound effects Video input - is the process of entering a full-motion recording into a computer

31. Output Devices Output is data that has been processed into a useful form called information Text - consists of characters that are used to create words, sentences, paragraphs Graphics - are digital representations of nontext information, such as images, drawings, charts, pictures, and photographs Audio - is any music, speech, or other sound that is stored and produced by the computer Video - consists of photographic images that are played back at speeds that provide the appearance of full motion in real-time.

32. Output Devices Continued An output device is any computer component capable of conveying information to a user Monitor - is a display device that conveys text, graphics, and video information visually and is housed in a plastic or metal case LCD vs. CRT Pixel - is a single point in an electronic image. Resolution - or sharpness and clarity of a monitor is related directly to the number of pixels it can display I.e 800 x 600

33. Output Devices Continued A printer is an output device that produces text and graphical information on a physical medium such as paper or transparency film Portrait vs. Landscape Dotmatrix vs. inkjet vs. laser Multifunction device - is a single piece of equipment that provides the functionality of a printer, fax machine, copier and scanner

34. Storage Storage - refers to the media on which data, instructions, and information are kept when they are not being processed, as well as the devices that record and retrieve these items. Also called secondary storage. Storage medium is the physical material on which data, instructions, and information are kept I.e. disk Storage device - is the mechanism used to record and retrieve these items to and from a storage medium