I. COMPUTER HARDWARE
* 4 functional parts :
1. Input Device
2. Central Processing Unit
3. Memory
4. Output Device
A.) Input Device
What is Input?
- everything we tell the computer is Input. Types of Input Data is the raw facts given to the computer.
Programs
- are the sets of instructions that direct the computer.
Commands
- are special codes or key words that the user inputs to perform a task, like RUN "ACCOUNTS". These can be selected from a menu of commands like "Open" on the File menu.
They may also be chosen by clicking on a command button. User response is the user's
answer to the computer's question, such as choosing OK, YES, or NO or by typing in text, for example the name of a file.
Input Devices
1.) Computer Keyboard - is a typewriter-like device that allows you to type in letters, numbers and other symbols for the Computer.
*** 3 Parts of the Keyboard ***
a) Alphanumeric Keypad
b) Numeric Keypad
c) Function Keys
2.)Touch Tablet
- is an electronic blackboard that can sense the tip of a pencil on its touch.
3.) Light Pen
- is an input device that reads light from the display screen, thus allowing you to point to a spot on the screen.
4.) Mouse
- is a hand operated pointing device.
5.) Puck
- is a pointing device, used much like a mouse, but it has a small magnifying glass with cross hairs.
6.) Joysticks
- are used in computer games.
7.) Bar Code Reader
- is a device for translating the bar codes into data for the computer.
* Bar Code - is a series of vertical black and white bars.
8.) Magnetic Disk Drives
- it is a device for converting magnetic spots on the surface of magnetic disk into electrical signals understandable by the computer.
9.) Magnetic Tape Drive
- is like a tape or a cassette recorder.
10) Glidepad
- uses a touch sensitive pad for controlling cursor. The user slides finger across the pad and the cursor follows the finger movement. For clicking there are buttons, or you can tap on the pad with a finger. The glidepad is a popular alternate pointing device for laptops.
11) Pen Input
- used esp. in Personal Digital Assistants (PDA) Pen Input is used for:
*Data Input
- by writing. PDA recognizes your handwriting. (If only your friends could, too!) Pointing Device
- functions like a mouse in moving a cursor around the screen and clicking by tapping the screen.
*Command Gestures
-you can issue commands by moving pen in patterns. So a certain kind of swirl would mean to save the file and a different kind of swirl could mean to open a new file.
12) Touchscreen
- make selection by just touching the screen.
13) Digitizers and Graphics Tablets
- converts drawings, photos, etc. to digital signal.
The tablets have special commands
14) Terminal
- consists of a keyboard and a screen so it can be considered an input device, especially some of the specialized types. Some come as single units.
Terminals are also called: · Display Terminals · Video Display Terminals or VDT
A dumb terminal has no ability to process or store data. It is linked to minicomputer, mainframe, or super computer. The keyboard and viewing screen may be a single piece of equipment.
An intelligent, smart, or programmable terminal can process or store on its own, at least to a limited extent. PCs can be used as smart terminals. A point-of-sale terminal (POS) is an example of a special purpose terminal. These have replaced the old cash registers in nearly all retail stores. They can update inventory while calculating the sale. They often have special purpose keys.
*For example, McDonalds has separate touchpads for each food item available.
15) Sound Input
- recording sounds for your computer requires special equipment. Microphones can capture sounds from the air which is good for sound effects or voices. For music the best results come from using a musical instrument that is connected directly to the computer. Software can combine music recorded at different times. You could be a music group all by yourself -singing and playing all the parts!
16) Voice Input Data entry
- talking data into the computer when your hands and eyes are busy should certainly be more efficient. You'd have to be very careful about your pronunciation!
*command and control - Telling the computer what to do instead of typing commands, like saying "Save file". Be careful here, too. The dictionary of understood words does not include some of the more "forceful" ones.
*speaker recognition - Security measures can require you to speak a special phrase. The computer must recognize your voice to let you in.
*speech to text - Translating spoken words direct to type would suit some authors just fine. You'd have to watch out for those "difficult to translate" phrases like "hmmm" and "ah, well, ... uhmmm."
17) Video Input
- a digital camera takes still photos but records the pictures on computer disks or memory chips. The information contained can be uploaded to a computer for viewing. A video camera or recorder (VCR) can record data that can be uploaded to the computer with the right hardware. Though it is not digital data, you can still get good results with the right software.
Both of these take huge amounts of storage. Photos make for very large files. A web cam is a tiny video camera designed especially to sit on your computer. It feeds pictures directly to the computer - no tape or film to develop. Of course you are limited by the length of the cable that connects the camera to the computer. But like any camera, it will take a picture of what you point it at!
18) Page scanner
- the scanner works like a copy machine. It captures a whole page and converts it to digital image. The scanned text cannot be edited at this point.
19) Hand scanner
- you move the device across the document or picture. It will capture only a section of a page or a large image. So the pieces of anything wider than the scanner would have to be recombined with some nifty software.
Special types of characters read with special devices
Bar Codes- Retail shops now use printed bar codes on products to track inventory and calculate the sale at the checkout counter. The US Post Office uses bar codes to sort mail, but the bars are different from those used for pricing products.
Optical Marks- A special machine "reads" the marks. Woe to the student who takes a test with this kind of score sheet and doesn't get those bubbles colored in correctly! Magnetic Ink- Bank account # is printed in special ink with magnetic qualities which can be read by the right machine.
Optical Characters- There are coding systems that use letters or special characters that are especially shaped to be easy for machines to read.
* 4 functional parts :
1. Input Device
2. Central Processing Unit
3. Memory
4. Output Device
A.) Input Device
What is Input?
- everything we tell the computer is Input. Types of Input Data is the raw facts given to the computer.
Programs
- are the sets of instructions that direct the computer.
Commands
- are special codes or key words that the user inputs to perform a task, like RUN "ACCOUNTS". These can be selected from a menu of commands like "Open" on the File menu.
They may also be chosen by clicking on a command button. User response is the user's
answer to the computer's question, such as choosing OK, YES, or NO or by typing in text, for example the name of a file.
Input Devices
1.) Computer Keyboard - is a typewriter-like device that allows you to type in letters, numbers and other symbols for the Computer.
*** 3 Parts of the Keyboard ***
a) Alphanumeric Keypad
b) Numeric Keypad
c) Function Keys
2.)Touch Tablet
- is an electronic blackboard that can sense the tip of a pencil on its touch.
3.) Light Pen
- is an input device that reads light from the display screen, thus allowing you to point to a spot on the screen.
4.) Mouse
- is a hand operated pointing device.
5.) Puck
- is a pointing device, used much like a mouse, but it has a small magnifying glass with cross hairs.
6.) Joysticks
- are used in computer games.
7.) Bar Code Reader
- is a device for translating the bar codes into data for the computer.
* Bar Code - is a series of vertical black and white bars.
8.) Magnetic Disk Drives
- it is a device for converting magnetic spots on the surface of magnetic disk into electrical signals understandable by the computer.
9.) Magnetic Tape Drive
- is like a tape or a cassette recorder.
10) Glidepad
- uses a touch sensitive pad for controlling cursor. The user slides finger across the pad and the cursor follows the finger movement. For clicking there are buttons, or you can tap on the pad with a finger. The glidepad is a popular alternate pointing device for laptops.
11) Pen Input
- used esp. in Personal Digital Assistants (PDA) Pen Input is used for:
*Data Input
- by writing. PDA recognizes your handwriting. (If only your friends could, too!) Pointing Device
- functions like a mouse in moving a cursor around the screen and clicking by tapping the screen.
*Command Gestures
-you can issue commands by moving pen in patterns. So a certain kind of swirl would mean to save the file and a different kind of swirl could mean to open a new file.
12) Touchscreen
- make selection by just touching the screen.
13) Digitizers and Graphics Tablets
- converts drawings, photos, etc. to digital signal.
14) Terminal
- consists of a keyboard and a screen so it can be considered an input device, especially some of the specialized types. Some come as single units.
Terminals are also called: · Display Terminals · Video Display Terminals or VDT
A dumb terminal has no ability to process or store data. It is linked to minicomputer, mainframe, or super computer. The keyboard and viewing screen may be a single piece of equipment.
An intelligent, smart, or programmable terminal can process or store on its own, at least to a limited extent. PCs can be used as smart terminals. A point-of-sale terminal (POS) is an example of a special purpose terminal. These have replaced the old cash registers in nearly all retail stores. They can update inventory while calculating the sale. They often have special purpose keys.
*For example, McDonalds has separate touchpads for each food item available.
15) Sound Input
- recording sounds for your computer requires special equipment. Microphones can capture sounds from the air which is good for sound effects or voices. For music the best results come from using a musical instrument that is connected directly to the computer. Software can combine music recorded at different times. You could be a music group all by yourself -singing and playing all the parts!
16) Voice Input Data entry
- talking data into the computer when your hands and eyes are busy should certainly be more efficient. You'd have to be very careful about your pronunciation!
*command and control - Telling the computer what to do instead of typing commands, like saying "Save file". Be careful here, too. The dictionary of understood words does not include some of the more "forceful" ones.
*speaker recognition - Security measures can require you to speak a special phrase. The computer must recognize your voice to let you in.
*speech to text - Translating spoken words direct to type would suit some authors just fine. You'd have to watch out for those "difficult to translate" phrases like "hmmm" and "ah, well, ... uhmmm."
17) Video Input
- a digital camera takes still photos but records the pictures on computer disks or memory chips. The information contained can be uploaded to a computer for viewing. A video camera or recorder (VCR) can record data that can be uploaded to the computer with the right hardware. Though it is not digital data, you can still get good results with the right software.
Both of these take huge amounts of storage. Photos make for very large files. A web cam is a tiny video camera designed especially to sit on your computer. It feeds pictures directly to the computer - no tape or film to develop. Of course you are limited by the length of the cable that connects the camera to the computer. But like any camera, it will take a picture of what you point it at!
18) Page scanner
- the scanner works like a copy machine. It captures a whole page and converts it to digital image. The scanned text cannot be edited at this point.
19) Hand scanner
- you move the device across the document or picture. It will capture only a section of a page or a large image. So the pieces of anything wider than the scanner would have to be recombined with some nifty software.
Special types of characters read with special devices
Bar Codes- Retail shops now use printed bar codes on products to track inventory and calculate the sale at the checkout counter. The US Post Office uses bar codes to sort mail, but the bars are different from those used for pricing products.
Optical Marks- A special machine "reads" the marks. Woe to the student who takes a test with this kind of score sheet and doesn't get those bubbles colored in correctly! Magnetic Ink- Bank account # is printed in special ink with magnetic qualities which can be read by the right machine.
Optical Characters- There are coding systems that use letters or special characters that are especially shaped to be easy for machines to read.
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