COMPUTER COMPONENTS

1. COMPUTER COMPONENTS Designed by: Regina Crews Student Support Services Secretary

2. What is a Computer? • Modern computers are electronic and digital devices that: • Respond to a specific set of instructions or a program. • Execute the prerecorded list of instructions.

3. A Computer System • A computer system includes hardware, software, data, and people. The actual machine, wires, transistors, and circuits are called hardware. Other devices such as printers, monitors, and scanners are also hardware.The instructions, or programs, for controlling the computer are called software.Data is text, numbers, sound, images or video. The computer receives data through an input device, processes the data, stores the data on a storage device, and produces output or information. The users, the people who use the computers, are also part of the system.

4. What Makes a Computer So Powerful? • Computers are not intelligent. They will do only what we ask them to do. • Speed – A computer can perform billions of calculations per second. • Reliability – The electronic components are dependable. • Accuracy – If data is entered correctly, computers generate error-free results. • Storage – Computers can store and retrieve unlimited amounts of data and information. • Communications – Computers can communicate and share resources with other computers.

5. Categories of Computers • Computers today come in all shapes and sizes, with specific types being especially suited for specific tasks. Computers are considered special purpose or general purpose. • Special-purpose computers are used mostly to control something else. Tiny chips are embedded in devices such as dishwashers, bathroom scales, or an airport radar system; and these chips control these particular devices. • General-purpose computers are divided into five categories, based on their physical size, function, cost, and performance. • Desktop and notebook computers are today’s most widely used personal computers. A desktop computer is designed so that all components fit on or under a desk. A notebook computer is a lightweight PC that can fit easily into the palm of your hand and is used primarily for functions such as phonebooks and calendars. • The midrange server is used by small to medium size companies and generally supports hundreds of users. • The modern mainframe computer is a large, expensive computer, capable of supporting hundreds or even thousands of users. • A supercomputer is the fastest type of computer and is used for specialized applications requiring immense amounts of mathematical calculations.

6. Computer System Components • Just about all computers, regardless of size, take raw data and change it into information you can use. The process involves input, process, output, and storage (IPOS). For example: • You input data with some type of input device. • The computer processes it to turn it into information • You output the information to some type of output device. • You store it for later retrieval. • Input, output, and processing devices grouped together represents a computer system. • Input devices: keyboard, hard disk drive, floppy disk drive, scanner, modem, mouse, joystick, trackball, graphics tablet, touch display screen, voice recognition devices, video input, and digital camera. • Output devices: monitor, printer, hard disk drive, floppy disk drive. • Storage devices: hard drive, CDs, magnetic tape cartridge, WORM disks, Zip and Jaz diskettes, floppy diskettes, super floppies, photo CDs, and DVDs.

7. System Components • The PC system case is the metal and plastic case that houses the main system components of the computer. • The motherboard or system board mounts into the case . It is a circuit board that contains many integral components. A circuit board is simply a thin plate or board that contains electronic components: • The central processing unit (CPU) • Memory • Basic controllers • Expansion ports and expansion slots

8. The Central Processing Unit • The CPU is also called the microprocessor, or central processor and is the brain of the computer. The CPU is housed on a tiny silicon chip. This chip contains millions of switches and Student Support Services that help your computer make important decisions. The switches control the flow of the electricity as it travels across the miles of Student Support Services. The CPU knows which switches to run on and which to turn off because it receives its instructions for computer programs. Programs are a set of special instructions written by programmers that control the activities of the computer. Programs are known as software.

9. Memory • Memory is also found on the motherboard. The easiest way to understand memory is to think of it as “short term” or “long term.” When you want to store a file or information permanently, you use secondary storage devices such as the computer’s hard disk drive or a floppy disk. You might think of this as long term. • Random Access Memory (RAM) – You can think about the memory of the motherboard as short term. • Read Only Memory (ROM) – ROM chips are found throughout a computer system. The computer manufacturer uses this type of chip to store specific instructions that are needed for the computer operations. These instructions remain on the chip regardless if the power is turned on or off. The most common of these is the BIOS ROM. The computer uses instructions contained on this chip to boot or start the system when you turn on your computer. A computer can read from a ROM chip, but cannot write or store data on the chip.

10. Input Devices • Input devices enable you to input data and commands into the computer and output devices enable the computer to give you the results of processing data. Some devices perform both input and output functions. The modem is an example. It is an input device when the sender inputs an e-mail message to be sent to a receiver. The modem is an output device when it sends the message. • The Keyboard: the most common input device for entering numeric and alphabetic data. • The Mouse: a pointing device that rolls around on a flat surface and controls the pointer on the screen. The pointer is an on-screen arrow-shaped object used to select text and access menus. • The Joystick – also a pointing device, used mostly for games. • The Trackball – a pointing device that works like a mouse turned upside down; the ball is on the top of the device. You use your thumb and fingers to operate the ball, thus controlling the arrow on the screen. Often found on the keyboards of laptop and notebook computers.

11. Graphics Tablet – a flat drawing surface on which the user can draw figures or write something freehand. The tablet is connected to the computer. Once the drawing has been inputted to the computer, it can be manipulated like a regular graphic. • Touch Display Screen – a special screen with pictures or shapes. You use your fingers to “point” to the desired object to make a selection. These screens can be found in many public establishments such as banks, libraries, delivery services, and fast-food restaurants. These are very user friendly input devices. • Voice Recognition Devices – used to “speak” commands into the computer and to enter text. These devices are usually microphones. The computer must have some type of voice recognition software installed before a voice recognition device can be used. • Scanners – change images into codes for input into the computer. There are various sizes and types of scanners: • Image scanners convert images into electronic form that can be stored in a computer’s memory. The image can then be manipulated.

12. Bar Code Scanners – read bar lines that ore printed on products (for example, in a grocery store or department store). • Magnetic Scanners – read encoded information on the back of credit cards. The magnetic strip on the back of the cards contains the encoded user’s account number. Video Input – allows images generated with camcorders and VCRs to be transferred to the computer. Once input into the computer, the images can be viewed on the screen and edited. Digital Cameras – the pictures taken with a digital camera are stored in the camera’s memory and can be transferred to the computer’s memory. These pictures can be viewed quickly and any imperfections can be edited.

13. Output Devices • Output devices display information. • Monitors – also called video display screens because images are displayed on the screen. They can be either monochromatic or color. A monochromatic monitor screen has a one-color display (white, amber, or green). • Printers – used to produce a paper or hard copy of the processing results. There are several types of printers with tremendous differences in speed, print quality, price and special features. • Laser printers – produce images using the same technology as copier machines. The image is made with a powder substance called toner. A laser printer produces high-quality output. • Ink Jet printers – allow less expensive color printing. The color is sprayed onto the paper. The same process used in laser printers is used in the inkjet printers; it just works more slowly. • Dot Matrix printers – have been around for a long time. They print by transferring ink to the paper by striking a ribbon with pins. The higher the number of pins (DPI) the better the output.

14. Storage Devices • As data is entered into the computer and processed, it is stored in RAM. If you want to keep a permanent copy of the data, you must store it on some type of storage medium such as the following: • Floppy diskettes – usually just called diskettes, are flat circles of iron-oxide coated plastic enclosed in a hard plastic case. They can hold 1.44 MB or more of data. • Hard disk drives – used to store data inside of the computer. They provide two advantages: speed and capacity. Accessing data is faster. • CD-R – make it possible for you to create your own CD-ROM disks that can actually be read by any CD-ROM drive. • Magnetic tape cartridges – used for making backup copies of large volumes of data. This is a very slow process and therefore is not used for regularly saving data. • WORM disks – optical disk storage devices that use laser beams and optical technology. Used for permanently storing large volumes of data. • Zip and Jaz diskettes – house disks that are capable of holding tremendous amounts of storage. • Photo CD – used to store digitized photographic images on a CD. The photos stored on these disks can be uploaded into the computer and used in other documents. • DVD media – full length movies can be stored on the DVD. It is the size of a regular CD and can be played in a regular CD player. You can also play them in your DVD player.

15. Communication Hardware • Communications hardware devices facilitate the transmitting and receiving of data. The first thing we think of when we think of communications hardware is the modem. • The word MODEM is an acronym for modulate-demodulate, which means to convert analog signals to digital and vice versa. This device enables a computer to transmit data over telephone lines. Computer information is stored digitally, whereas information sent over telephone lines is transmitted in the form of analog waves. Both the sending and receiving must have a modem • Cable modem – uses coaxial cable to send and receive data. This is the same type of cable used for cable TV. The bandwidth, which determines the amount of data that can be sent at one time is much greater with a cable modem. A cable modem can be connected directly to your computer or connected to a set top box used with your television.

16. Summary • In this workshop you learned: • A computer is an electronic device that receives data, processes data, produces information, and stores the data and information. • A computer derives its power from its speed, reliability, accuracy, storage, and communications capability. • Categories of computers include personal computers (desktop and notebook), palmtops or handhelds, etc. • Just about all computers perform the same general operations: input, process, output, and storage. • Input, output, and processing devices grouped together represent a computer system. • The motherboard is the center of all processing. • The motherboard contains the CPU, memory, and basic controllers for the system. • The central processing unit is the brains of the computer.

17. Random access memory is volatile and is used to store instructions, data, and information temporarily. • Read-only memory is nonvolatile and is used to store permanent instructions needed for computer operations. • Input devices enable you to input data and commands into the computer. • The most common input devices are the keyboard and the mouse. • The mouse is a pointing device used to input data. • Printers are used to produce a paper or hard copy of the processed results. • To maintain a permanent copy of data, you must store it on some type of storage medium. These may include floppy diskettes, hard drives, CDs, magnetic tape cartridges, and WORM disks. • A modem is a type of communication device.

18. Test Your Knowledge • 1. ___________is text, numbers, sound, images, or video. • A. Software • B. Information • C. Hardware • D. Data • A(n) ____________ is designed so all components fit on or under a desk. • Desktop computer • Midrange server • Mainframe computer • Supercomputer

19. 3. A(n) ______ is an electronic and digital device. • A. client B. node C. server D. computer • The _________contains the CPU, memory, and basic controllers. A. memory B. motherboard C. processor D. expansion slot • The ________ is considered the brains of the computer. A. program B. ALU C. CPU D. control unit • A printer would be considered a(n) ____________ A. controller B. output device C. input device D. USB

20. 7. Laser, ink jet, and dot matrix are types of ___________. • A. monitors • B. printers • C. storage devices • D. input devices • Monitors and printers are types of ______________. A. input devices B. output devices C. storage devices D. ports • Floppy diskettes are also called ______________. A. diskettes B. hard drives C. CDs D. magnetic disks

21. True/False • 1. The instructions for controlling the computer are called hardware. • 2. Information is processed data. • 3. A notebook computer is a lightweight computer that can fit into a briefcase. • 4. Input and output devices perform the same functions. • 5. The mouse is a pointing device that rolls around on a flat surface and controls the pointer. • Fill in the Blank • 1. A(n) ________is used to enter data into the computer. • 2. ____________ and _____________ are the most popular input devices. • 3. Hard disks and floppy diskettes are types of ________ mediums. • FOR MORE INFORMATION ON COMPUTER COMPONENTS TAKE THE CIS 096 COURSE OFFERED HERE AT WALLACE COMMUNITY COLLEGE.

22. Thank you for your participation in this workshop. We hope you found it helpful. Do not forget to complete an Academic Enrichment Summary. If you are viewing this workshop via the internet please come by the Student Support Services office to complete an Academic Enrichment Summary or you may click on the link in the instruction box on the Workshops page and print one out or e-mail it to rcrews@wallace.edu so that we may document your participation. Handouts available upon request. • EXIT