Output Devices
An output device has been processed and the computer is giving us feedback.Here is a list of output devices and their meaning.
1) Printer : Printer information is called hard copy. These are needed to compensate for the difference in speeds between the CPU and the printer.
Impact Printers: forms characters and graphics on a piece of paper.
Non-Impact Printers: forms characters on paper without striking the paper.
There are four types of printers : Dot-matrix , Ink-jet printer ,Laser printer and plotter printer.
2) Raster and Vector images : Raster images are not accurate ; they show dots and pixels on the picture. On the other hand vector images are more accurate.
For disabled persons there are braille printers and keyboards , special purpose keyboards , eye sensor readers and speech recognition.
Wednesday, 12 December 2012
Input Devices
Input and Output Devices
Input is anything which you enter in the computer. Here is a list of input devices and their meaning :
1) keyboard : It can allow you to enter data in the computer system. Many desktop computers have a numeric keyboard at the side. A standard computer usually has a QWERTY keyboard.
2) mouse : This is a pointing device ; there are three types of a mouse : mechanical mouse , optical mouse and cordless mouse.
3) trackball : This is another pointing device with a ball - mechanism on its top.
4) Joystick : Another pointing device with a vertical leaver on the base.
5) Bar code reader : this uses laser beams to read bar codes.
6) Magnetic ink reader (MICR) : This can read text printed with magnetized ink.
7) Scanner : light-sensing device that converts printed text and graphics into a digital form. There are two types of scanners; a flatbed scanner and a handheld scanner.
8) optical character recognition (OCR) : this device works with word processors and distinguishes characters by the shape.
9) Graphics tablet : This is a flat electronic plastic board for writing or drawing.
10) Optical mark recognition (OCR) : this device can sense circles and rectangles.
11) Light pen : a pointing device that can detect the presence of light.
12) Digital camera : Takes pictures and stores them digitally.
13) handwriting recognition : when you write with your own handwriting on an interactive board and the computer digitally changes your writing to another font.
14) Electronic cards : Used to pay , they store money
Input is anything which you enter in the computer. Here is a list of input devices and their meaning :
1) keyboard : It can allow you to enter data in the computer system. Many desktop computers have a numeric keyboard at the side. A standard computer usually has a QWERTY keyboard.
2) mouse : This is a pointing device ; there are three types of a mouse : mechanical mouse , optical mouse and cordless mouse.
3) trackball : This is another pointing device with a ball - mechanism on its top.
4) Joystick : Another pointing device with a vertical leaver on the base.
5) Bar code reader : this uses laser beams to read bar codes.
6) Magnetic ink reader (MICR) : This can read text printed with magnetized ink.
7) Scanner : light-sensing device that converts printed text and graphics into a digital form. There are two types of scanners; a flatbed scanner and a handheld scanner.
8) optical character recognition (OCR) : this device works with word processors and distinguishes characters by the shape.
9) Graphics tablet : This is a flat electronic plastic board for writing or drawing.
10) Optical mark recognition (OCR) : this device can sense circles and rectangles.
11) Light pen : a pointing device that can detect the presence of light.
12) Digital camera : Takes pictures and stores them digitally.
13) handwriting recognition : when you write with your own handwriting on an interactive board and the computer digitally changes your writing to another font.
14) Electronic cards : Used to pay , they store money
Tuesday, 11 December 2012
Word Processing
Word Processing
Word Processing is used for the creation of text documents. We mainly use microsoft word or word perfect.
The functions of a word processor are :
Word Processing is used for the creation of text documents. We mainly use microsoft word or word perfect.
The functions of a word processor are :
- Text editing
- Word wrap and centering
- Search and replace , Move and copy
- Layout settings
- Headers, Footers and page numbers
- Style sheets
- Clip arts and pictures
- Preview , print and group print
- Footnotes and end notes
- Spelling checker and thesaurus
Style Sheets are the important so i'm going to tell you what their function is.
When you apply a style , you apply the whole group of formats in one simple task. For example instead of taking three steps you can only take 1 by using the Title style , heading 1 and heading 2 .....You can create or view these styles go to the styles and formatting task pane.
Advanced Functions
Mail merge : this is used by combining together a form of letter and a list of data , by that you will create a personalized letter.
Table of contents : This is a list of headings in a document. You can get an over-view of the topics in that particular document
Indexes : This is a list of the terms and topics discussed in a document with the pages they appear on.
*Important to note that both table of contents and indexes are updated automatically.
Monday, 10 December 2012
Computer Logic
Computer Logic
2-state devices also known as bistable devices are like a switch on a wall , it can be only one of two possible states : ON or OFF .
However,computers represent the letters of the alphabet by the binary system .Binary is only 2 numbers : 1 and 2 . With 3 bits we represent 8 characters and with 4 bits we represent 16 characters.
There are also number conversions . You do them by using the LSB ( least significant figure and the MSB ( most significant figure) . When studiying computer studies you should know how to convert these :
2-state devices also known as bistable devices are like a switch on a wall , it can be only one of two possible states : ON or OFF .
However,computers represent the letters of the alphabet by the binary system .Binary is only 2 numbers : 1 and 2 . With 3 bits we represent 8 characters and with 4 bits we represent 16 characters.
There are also number conversions . You do them by using the LSB ( least significant figure and the MSB ( most significant figure) . When studiying computer studies you should know how to convert these :
- converting binary to decimal
- converting decimal to binary
- converting binary to hexa decimal
- converting hexa decimal to binary
- converting decimal to hexa decimal
- converitng hexa decimal to decimal
In a computer we use the representation of characters by the ascii code and the unicode.The ascii code is an 8 bit device and can represent 256 characters. It also has it's limitations.
Ascii stands for : - American Standard Code for Information Interchange.
A bit = 0 or 1
Byte = 8 bits
Kilobyte = 1024 bytes
Megabyte = 1024 kilobytes
Gigabyte = 1024 megabytes
Terabyte = 1024 gigabytes
Analogue and Digital data
An analogue device is one which data is represented by some quantity which is continuously changing , Hence a digital device shows data at discrete intervals.
A modem ( MODulator & DEModulator ) = the purpose is to convert between the analogue signals and the telephone cables and the digital signals used by a computer.
Either than a modem ,network cards and sound cards can also be used.
From analogue to digital is <ADC> & from digital to analogue is <DAC>
Saturday, 13 October 2012
Defregmentation and compressed folders .
Defragmentation
The disk defregmentor (defrag) rearranges the files and free space on your disk so that you can open files more quickly , because they are stored in adjacent units and so free space will be consolidated .
To start Defrag you just go on start , programs , accessories , system tools and disk defragmentor .
You choose the drive you want to defrag and apply the defrag on . If you change your mind you can stop the defrag or pause it and even show more details if you would like .
Compressed Folders
Folders are compressed using the zipped folders feature . They use less space and can be transferred to other computers more quickly . Once you have created the compressed folder you can compress files by just dragging what you want directly to the folder .
You can create a zipped folder by opening my computer , double click on the drive , on the file menu press new and click compressed folder . You name it then press enter
Anti-virus Software.
The disk defregmentor (defrag) rearranges the files and free space on your disk so that you can open files more quickly , because they are stored in adjacent units and so free space will be consolidated .
To start Defrag you just go on start , programs , accessories , system tools and disk defragmentor .
You choose the drive you want to defrag and apply the defrag on . If you change your mind you can stop the defrag or pause it and even show more details if you would like .
Compressed Folders
Folders are compressed using the zipped folders feature . They use less space and can be transferred to other computers more quickly . Once you have created the compressed folder you can compress files by just dragging what you want directly to the folder .
You can create a zipped folder by opening my computer , double click on the drive , on the file menu press new and click compressed folder . You name it then press enter
Anti-virus Software.
Main components of a computer
The Computer On The Inside
The central processing unit (CPU) and the main memory are chips that can be found clipped to the mother board in the system unit .
The CPU is the processor of the computer , it is the brain where all the system combines together . The CPU measures also the speed of your computer mostly in Mhz or Ghz .
The main memory is the primary storage of the computer . It stores the data and instructions that are held there for use of the CPU .
The backing storage is where you store amounts of data outside of the main storage .You must have at least one form of backing storage.
What is a bus ?
A set of parallel connecting to two or more units forms what we call a bus . A bus is a data roadway along which data and commands travel .The greater the capacity of the bus is the more speed the computer will have .
In a computer we have three types of buses :
-The address bus
-The data bus
-The control bus .
The central processing unit (CPU) and the main memory are chips that can be found clipped to the mother board in the system unit .
The CPU is the processor of the computer , it is the brain where all the system combines together . The CPU measures also the speed of your computer mostly in Mhz or Ghz .
The main memory is the primary storage of the computer . It stores the data and instructions that are held there for use of the CPU .
The backing storage is where you store amounts of data outside of the main storage .You must have at least one form of backing storage.
What is a bus ?
A set of parallel connecting to two or more units forms what we call a bus . A bus is a data roadway along which data and commands travel .The greater the capacity of the bus is the more speed the computer will have .
In a computer we have three types of buses :
-The address bus
-The data bus
-The control bus .
Formatting and Scan disk
Formatting a Diskette
When you format a disk you divide the disk into tracks and sectors
When you format a disk you divide the disk into tracks and sectors
Scan Disk
Block diagram .
This video consists of components of hardware and software , application software and system software and also a block diagram of the computer system .
Super Computers Video .
This is an 'apple' super computer , it shows you how to connect them and some pictures of them .
The computer System.
The Computer System
When we talk to our friends , families and also strangers , we just refer to the words 'data' and 'information' as the same thing . But it's not , in fact it really is this :
Data + Structure = Information
The computer will process data , add the structure and give us information .
What is a computer ?
A computer is a machine which can be programmed to accept the data we put in and gives out information .
Input - Process - Output
We put our data in the computer (input) , then the machine will process it ,finally information comes out
(output).
So we can just say that a compute is a device that accepts input , processes data ,stores data and produces output .
Input is the process of entering data in the computer .Some examples used for inputting data are the keyboard , mouse and the modem.
Output is getting processed data out of the computer . Either the computer will display the data on the monitor screen which we call soft copy or either sends the data to a printer and we call that hard copy.
When we talk to our friends , families and also strangers , we just refer to the words 'data' and 'information' as the same thing . But it's not , in fact it really is this :
Data + Structure = Information
The computer will process data , add the structure and give us information .
What is a computer ?
A computer is a machine which can be programmed to accept the data we put in and gives out information .
Input - Process - Output
We put our data in the computer (input) , then the machine will process it ,finally information comes out
(output).
So we can just say that a compute is a device that accepts input , processes data ,stores data and produces output .
Input is the process of entering data in the computer .Some examples used for inputting data are the keyboard , mouse and the modem.
Output is getting processed data out of the computer . Either the computer will display the data on the monitor screen which we call soft copy or either sends the data to a printer and we call that hard copy.
Friday, 12 October 2012
Welcome to my blog !
Welcome to my blog ,
In this blog I will be posting the computer and how it works...
I hope you enjoy reading my posts and also find them as something new to learn.
Regards,
Mariah
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