10 INPUT DEVICES AND THEIR FUNCTIONS.docx

10 INPUT DEVICES AND THEIR FUNCTIONS 1. KEYBOARD A keyboard consists of a series of keys that can be pressed to input commands or letters. These are used to write documents but can be used to navigate user interfaces in lieu of a mouse.

2. MOUSE A mouse consists of a ball or laser that tracks the movement of the device. The computer is able to register the movement of the mouse and translate it as movement of the cursor on the screen. A mouse also contain buttons that allow the user to select objects, move windows or open applications. Many also include a scrolling wheel to allow for scrolling through long documents or Web pages.

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3. TRACKBALL These devices work like a standard mouse except the users rolls a ball inside a base rather than moving the device across the table top. Many users prefer a trackball to a mouse, because it involves less wrist movement, reducing repetitivemotion issues.

4. TOUCHPAD This is a device typically found on laptop computers. It works like a mouse or trackball, except it's a flat panel you move your finger across. The motion of your finger registers as cursor movement on the screen. Many touchpads now enable gestures to scroll through documents or zoom in on a photo. Buttons are typically below the touchpad. 2

5. GRAPHICS TABLET These devices are used like a piece of paper and a pencil. These allow artists to draw more naturally in a graphics application. They have a stylus that looks like a plastic pencil that you can use to draw on a flat panel. The device will register the pressure of the user's hand to draw lighter or darker lines on screen. Many even have erasers on the back that allow you to erase mistakes with the stylus.

6. TOUCHSCREEN MONITOR These devices double as an output and input device. They display the computer environment on screen, and allow a user to manipulate and interface with it just by touching the 3

screen. These can take the place of a mouse and even a keyboard if a virtual keyboard application is installed.

7. JOYSTICK These devices are primarily used for computer gaming. They consist of a stick on a base with various buttons that all have different functions. It operates similar to a yoke on an aircraft, making them suitable for flight simulators.

8. SCANNER These devices allow a user to input a photograph or document into the computer. By placing a piece of media in a scanner,

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you can create an image file that can be opened and manipulated on the computer.

9. MICROPHONE This is a device used to input voice data and sound. You hold the microphone up to a source, most likely a person's mouth, and it registers the sounds and inputs them into audio recording applications. This will let you do many things, from recording a song to talking to someone on Skype.

10.

WEBCAM

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This is a small video camera that takes video and inputs it into the computer. These allow you to record and send small videos or have a video chat with someone over the Internet.

10 OUTPUT DEVICES AND THEIR FUNCTIONS 1. COMPUTER MONITOR - Computer has a got a monitor or display Unit that allows one to see whatever is being done, when typing in word you will be able to see the words, sentence as you type from the computer monitor, a monitor is basically a electronic screen on which words, numbers, texts, graphics and drawing can be viewed.

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2. PRINTER - as an external output device that enables one to output all relevant soft copies into a hardcopy materials like paper, basically printer print what you have in your screen.

3. SPEAKERS - Speaker gives you a sound output if connected to your computer, while other computers comes with built in speakers some operate with external speakers.

4. HARD DISK - a computer hard disk is also an output device where one can store all the information in one place.

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5. HEADPHONE - These are also computer output devices. Headphones give sound output from the computer. They are similar to speakers, except they are worn on the ears so only one person can hear the output at a time.

6. FLOPPY DISKS - These were some of the original output devices that were used to save data, but time has seen them getting out of market for the newer output devices.

7. FLASH DISK - This is one of the portable output devices that can be used in any computer as long as you have a USB connection.

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8. COMPACT DISK - Some compact disks can be used to put information on. This is called burning information to a CD.

9. COMPUTER VCD - is the higher version of a CD does output both audios and video files

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Computer DVD - is a higher version of computer VCD

does output both audios and video files

7 INTERNAL DEVICES THAT CAN BE FOUND INSIDE SYSTEM UNIT AND THEIR FUNCTIONS 1. MOTHERBOARD: The motherboard is the main component of computer. It is a large rectangular board with integrated circuitry that connects the other parts of the computer 9

including the CPU, the RAM, the disk drives(CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots. 2. OPTICAL DRIVE: An optical drive is any storage device that uses light to read and write information. Common optical disc drives include CD, DVD, and Blu-ray drives. An optical drive in a computer system allows you to use CDs, DVDs, and Blu-ray discs to listen to music or watch a movie. 3. POWER SUPPLY UNIT: A power supply unit (PSU) converts mains AC to low-voltage regulated DC power for the internal components of a computer. 4. HARD DISK DRIVE: A hard disk drive is a hardware device that's used to store information like software and files. Hard disk drives are the mechanism that reads and writes data on a hard disk. 5. FLOPPY DRIVE: The floppy drive is the piece of computer hardware that's used to read and write data on 3.5 or 5.25 inch floppy diskettes. 6. CASE FAN: Alternatively referred to as a system fan, a case fan is a fan located inside a computer case attached to the 10

front or back of the computer that helps bring air into the case and also take hot air out of the case. 7. RAM: The Random-Access Memory (RAM) stores the code and data that are being actively accessed by the CPU.

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GENERATIONS OF COMPUTER 1. First Generation (1940-1956) Vacuum Tubes The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language, the lowestlevel programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts. 2. Second Generation (1956-1963) Transistors Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 12

1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement

over

the

vacuum

tube.

Second-generation

computers still relied on punched cards for input and printouts for output. 3. Third Generation (1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of the

third

miniaturized

generation and

of

computers.

placed

on

Transistors

silicon

chips,

were called

semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors 13

and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory.

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