Thursday, 3 September 2015

Operating System

What are the types of system software?

System software consist of the program that control or maintain the operations of a computer and its devices. Two types of system software are operating system and utility programs. An operating system(OS) contains instructions that work together to coordinates all the activities among computer hardware resources. A utility program performs maintenance-type tasks, usually related to managing a computer, its devices, or its programs.

What are the functions of an operating system?

The operating system provides a user interface, manage programs, manage memory, coordinates tasks, configures devices, establish an internet connections and monitors performance. The user interfaces controls how data and instructions are entered and how information is displayed. Two types of user interface are a command-line interface and a graphical user interface(GUI). Managing programs refer to how many users, and how many programs, an operating system can support at one time. An operating system can be single user/single tasking, single user/multitasking,multi-user, or multiprocessing. Memory management optimizes the use of random access memory(RAM). Virtual memory allocates a portion of a storage medium to function as additional RAM. Coordinating tasks determines the order in which tasks are processed. Configuring devices involved loading each device's driver when a user boots the computer. A driver is a program that tells the operating system how to communicate with a specific device. Establishing an internet connection sets up a connection between a computer and an internet access provider. A performance monitor is a program that assesses and reports information about computer resources and devices.

What is the purpose of the utilities included with most operating system?

Most operating system include several built-in utility programs. A file manager performs functions related to file management. A search utility attempts to locate a file on your computer based on criteria you specify. An image viewer displays, copies, and prints the contents of a graphics file. A personal firewall detects and protects a personal computer from unauthorized instrusions. An uninstaller removes a program and any associated entries in the system files. A disk scanner searches for and removes unnecessary files. A disk defragmenter reorganizes the files and unused space on a computer's hard disk. A diagnostic utility compiles and reports technical information about a computer's hardware and certain system software programs. A backup utility is used to copy, or back up, selected files or an entire hard disk to another storage medium. A screen saver displays a moving image or blank screen if no keyboard or mouse activity occurs for a specified time.

What are features of several stand-alone
operating system?

A stand-alone operating system is a complete operating system that works on a desktop computer, notebook computer, or mobile computing device. Stand-alone operating system include Windows XP, Windows Vista, Mac OS X, UNIX, and Linux. Windows XP is a fast, reliable Windows operating system, providing better performance, increased security, and a simpler look than previous Windows version. Windows Vista, successor to Windows XP, is a Microsoft's fastest, most reliable and efficient operating system to date, offering quicker program start up, built-in diagnostic, automatic recovery, improved security, and enhanced searching and organizing capabilities. Mac OS X is a multitasking GUI operating system available only for Apple computers. Unix is a multitasking operating system that is flexible and powerful. Linux is a popular, multitasking UNIX-type operating system that is open source software, which means its code is available to the public for use, modification, and redistribution.

What devices use embedded operating system?

Most smart phones and small devices have an embedded operating system that resides on a ROM chip. Popular embedded operating system include Windows Embedded CE, Windows Mobile, Palm OS, BlackBerry, embedded Linux, and Symbian OS. Windows Embedded CE is a scaled-down Windows operating system designed for use on communications, entertainment and computing devices with limited functionality. Windows Mobile, an operating system based on Windows Embedded CE, works on specific types of devices, such as smart phones and PDAs, called a POCKET PC. Palm OS is an operating system used on smart phone and PDAs. The BlackBerry operating system runs on handheld devices supplied by RIM. Embedded Linux is a scaled-down Linux operating system for smart phones, PDAs, and other devices. Symbian OS is an open source multitasking operating system designed for smart phones.

What is the purpose of several stand-alone
utility programs?

Stand-alone utility programs offer improvements over features built into the operating system or provide features not included in the operating system. An antivirus program protects computers againts a virus, or potentially damaging computer program, by identifying and removing any computer viruses. A spyware remover detects and deletes spyware and delete spyware and similar programs. An adware remover detects and deletes adware. An anti-spam program attempts to remove spam before it reaches your inbox. Web filtering software restricts access to certain material on the web. A phising filter warns or block you from potentially fraudelent or suspicious web sites. A pop-up blocker stops pop-up ads from displaying on web pages. A file compression utility shrinks the size of a file. A file conversion utility transforms the contents of a file from one format to another. A media player allows you to view images and animation, listen to audio, and watch video files on a computer. CD/DVD burning software writes on a recordable or rewriteable CD or DVD. A personal computer maintenance utility identifies and fixes operating system or disk problems and improves a computers's performance.

Thursday, 20 August 2015

SOCCER SPORT AND GOOGLE NEWS

SOCCER SPORT

Soccer is the most popular sports in the world. Soccer is a sport played outdoor on a rectangular field. There are 11 player for each team, each match must have 2 teams to play the sport. The playing either have forward, midfield, defensive and goalkeeper. The aim of the game is to score the goal, which achieved by kicking or heading the ball to the opponent team goal. I like soccer because the game so interested to play and watch it too. Have many supported in the game, so the game can make us become united become one. Soccer become more interested when the team we a supported score a many goal and won the match.

GOOGLE NEWS

Google news is a facility provide on the google internet for all to got a new information about what happen around the world. The information be provided by google to give a latest news for a google news user with a free without pay any for their services. i like to use a Google news because the service for got a information is free and easy been provided to all users to make sure the internet users can got a information about what happen in the world when them using a internet

News article about soccer :

KUALA LUMPUR: Rising Liverpool star Jordon Ibe mustered a superb solo effort to equalise against a spirited Malaysia XI side on Friday (Jul 24) and salvage a draw as the Reds wrapped up an unbeaten Asia summer tour.

The 19-year-old winger, who has impressed during the Asia swing, took on three players before lashing the ball in from just inside the box in the 28th minute.

Liverpool struggled to get into a rhythm throughout the match despite summer signing James Milner and new captain Jordan Henderson pulling the strings to create several chances for the Reds. But Ibe repeatedly tormented his markers down Liverpool's right - he had two penalty claims turned down in the first 45 minutes - possibly burnishing his chances to replace Raheem Sterling, who joined Manchester City last week.

The Reds had won their three earlier matches against the Thai All Stars in Bangkok, and in Australia against the Brisbane Roar and Adelaide United.

The Malaysian XI squad started with five foreigners, and one of them - Liberian international striker Patrick Wleh, who goes by his middle name Ronaldinho - shocked the Reds by putting the hosts ahead in the 13th minute. Wleh capitalised on some shoddy defending to collect a through ball, scoring with a lob over Adam Bogdan.

The scoreless second half saw Liverpool labouring to create chances but with little actual menace.

- AFP/fl

Wednesday, 19 August 2015

CATHODE RAY

How a cathode-ray tube (CRT) TV works

An antenna (aerial) on your roof picks up radio waves from the transmitter. With satellite TV, the signals come from a satellite dish mounted on your wall or roof. With cable TV, the signal comes to you via an underground fiber-optic cable.
The incoming signal feeds into the antenna socket on the back of the TV.
The incoming signal is carrying picture and sound for more than one station (program). An electronic circuit inside the TV selects only the station you want to watch and splits the signal for this station into separate audio (sound) and video (picture) information, passing each to a separate circuit for further processing.
The electron gun circuit splits the video part of the signal into separate red, blue, and green signals to drive the three electron guns.

The circuit fires three electron guns (one red, one blue, and one green) down acathode-ray tube, like a fatglassbottle from which the air has been removed.
The electron beams pass through a ring of electromagnets. Electrons can be steered by magnets because they have a negative electrical charge. The electromagnets steer the electron beams so they sweep back and forth across the screen, line by line.
The electron beams pass through a grid of holes called a mask, which directs them so they hit exact places on the TV screen. Where the beams hit the phosphors (colored chemicals) on the screen, they make red, blue, or green dots. Elsewhere, the screen remains dark. The pattern of red, blue, and green dots builds up a colored picture very quickly.
Meanwhile, audio (sound) information from the incoming signal passes to a separate audio circuit.
The audio circuit drives the loudspeaker (or loudspeakers, since there are at least two in a stereo TV) so they recreate the sound exactly in time with the moving picture.

PLASMA RAY

What is plasma anyway?

In schools they teach us that all substances come in three basic flavors or states of matter: solid, liquid, and gas. But they're wrong! There's a fourth flavor called plasma (and, arguably, there are even more states of matter too that we won't get into here). What exactly is a plasma and how does it relate to solids, liquids, and gases?

Suppose you have a lump of freezing cold ice (a solid). Heat it up a bit and you'll get a liquid (water). Heat it up a bit more and, pretty soon, you'll have a gas (steam). The more heat you supply, the more energy you inject. The more energetically the molecules (oratoms) have, the further apart they can push and the more they move about. In a solid like water, the molecules are bound tightly together; in liquid water, the molecules are free to move past one another (that's why water can pour and flow); in steam (gaseous water), the molecules are completely free of one another and have so much energy that they spread out to fill all the space available.

But what happens if you don't stop there? What if you keep on heating a gas? The molecules and atoms inside it break apart, releasing some of their electrons so they move freely in and around it. When atoms disintegrate like this, they form positively charged particles called ions. The mixture of positively charged ions and negatively charged electrons in a plasma turns it into a kind of hot soup that will conduct electricity very easily. That's what we mean by a plasma. It's a special type of gas in which some of the atoms have become ions (an ionized gas, in other words).

How a plasma TV set makes its picture

If you've read our articles on energy-saving fluorescent lamps (also known as CFLs) and neon lamps (the lamps that make brightly colored displays in our streets), you'll know how they make light by buzzing electricity through a gas. Imagine if you built a TV screen out of millions of microscopically tiny CFLs or neon lamps, each of which could be switched on or off very quickly, as necessary, by an electronic circuit, to control all the separate pixels (lit-up, colored squares) on the screen. That's pretty much how a plasma TV works and it's very different to other kinds of television technology: in a conventional (cathode-ray) television, the picture is built up by scanning an electron beam back and forth over a screen treated with chemicals called phosphors; in an LCD TV (liquid-crystal display television), polarizing crystals make light rays bend to switch the pixels on and off.

The pixel cells in a plasma TV have things in common with both neon lamps and CFLs. Like a neon lamp, each cell is filled with tiny amounts of neon or xenon gas. Like a CFL, each cell is coated inside with phosphor chemicals. In a CFL, the phosphor is the chalky white coating on the inside of the glass tube and it works like a filter. When electricity flows into the tube, gas atoms crash about inside it and generate invisible ultraviolet light. The white phosphor coating turns this invisible light into visible white light. In a plasma TV, the cells are a bit like tiny CFLs only coated with phosphors that are red, blue, or green. Their job is to take the invisible ultraviolet light produced by the neon or xenon gas in the cell and turn it into red, blue, or green light we can actually see.

Much like the picture in an LCD screen, the picture made by a plasma TV is made from an array (grid) of red, green and blue pixels (microscopic dots or squares).
Each pixel can be switched on or off individually by a grid of horizontally and vertically mounted electrodes (shown as yellow lines).
Suppose we want to activate one of the red pixels (shown hugely magnified in the light gray pullout circle on the right).
The two electrodes leading to the pixel cell put a high voltage across it, causing it to ionize and emit ultraviolet light (shown here as a turquoise cross, though it would be invisible in the TV itself).
The ultraviolet light shines through the red phosphor coating on the inside of the pixel cell.
The phosphor coating converts the invisible ultraviolet into visible red light, making the pixel light up as a single red square.

Sunday, 9 August 2015

Input, output and storage device

You Are Reading

INPUT OUTPUT STORAGE DEVICES

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HARDWARE .....

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INPUT DEVICES

Input is any data or instruction that you enter into the memory of a computer.
There are four types of input: which are text, graphic, audio & video.

INPUT DEVICES

Input devices are any electronic device connected to a computer and produces input signals.

a) INPUT DEVICES FOR TEXTS

BARCODE SCANNER

An optical reader is a device that uses a light source to read characters, marks and codes and then converts them into digital data that a computer can process.

KEYBOARD

b) INPUT DEVICES FOR GRAPHICS

SCANNER

captures images from photographic prints, posters, magazine pages and similar sources for computer editing and display.

DIGITAL CAMERA

allows you to take pictures and store the photographed images digitally.

c) INPUT DEVICES FOR AUDIO

MICROPHONE

Audio input is the speech, music and sound effects entered into the computer. This can be done using input devices such as a microphone and digital musical instruments like the Musical Instrument Digital Interface (MIDI) keyboard.

d) INPUT DEVICES FOR VIDEO

Video input is input of motion images captured into the computer by special input devices.

CCTV

A Closed-Circuit Television (CCTV) video camera is a type of digital video camera that enables a home or small business user to capture video and still images.

WEBCAM

A webcam is any video camera that displays its output on a web page.

VIDEO CAMERA

A digital video camera allows you to record full motion and store the captured motion digitally.

e) POINTING DEVICES

TRACK BALL

GRAPHIC TABLET

TOUCH SCREEN

MOUSE

A pointing device is another form of input device. Pointing devices such as a mouse, trackball, graphics tablet and touch screen are used to input spatial data into the computer.

OUTPUT DEVICES

An output device is hardware that is capable of delivering or showing information to one or more users. An output device shows, prints and presents the results of a computer’s work.

TYPES OF OUTPUT DEVICES

A display device is an output device that visually conveys texts, graphics
and video information. A printer is an output device that prints text and graphics on a physical medium such as paper or transparency film.An audio output device produces music, speech, or other sounds.

FACSIMILE MACHINE

MONITOR

A monitor is an example of an output device that can be used to display text. It can also display graphics and video. It is similar to a television set that accepts video signals from a computer and displays information on its screen.

PRINTER / PHOTO PRINTER

A printer is another example of an output device that can be used to print text, apart from graphics, on mediums such as paper, transparency film or even cloths.

A photo printer is a colour printer that produces photo-lab-quality pictures.

An image setter is a high resolution output device that can transfer electronic text and graphics directly to film, plates, or photo-sensitive paper.

SPEAKER

A pair of speakers is an audio output device that generates sound. A woofer or subwoofer is used to boost the low bass sound and is connected to the port on the sound card.

LCD PROJECTOR

A Liquid Crystal Display (LCD) projector uses its own light source to project what is displayed on the computer on a wall or projection screen. A digital light processing (DLP) projector uses tiny mirrors to reflect light which can be seen clearly in a well-lit room.

MOTHERBOARD

This is a motherboard and its components. Motherboard is the main circuit board of the system unit, which has some electronic components attached to it and others built into it.

This is the location of the Central Processing Unit (CPU).

This is where the expansion slots are located.

These are the Peripheral Component Interconnect (PCI)
expansion slots.Peripheral Component Interconnect. A personal computer local bus which runs at 33 MHz and supports Plug and Play. It provides a high-speed connection with peripherals and allows connection of seven peripheral devices

In addition, the Industry Standard Architecture (ISA) expansion slots are also the components of the motherboard.Industry Standard Architecture. A PC expansion bus used for modems, video displays, speakers, and other peripherals.PCs with ISA commonly have some 8-bit and some 16-bit expansion slots.

STORAGE

WHAT IS COMPUTER STORAGE ?

Information and documents are stored in computer storage so that it can be retrieved whenever they are needed later on.

TYPES OF COMPUTER STORAGE

Primary storage is known as the main memory of a computer, including RAM (Random-Access Memory)
and ROM (Read-Only Memory). It is an internal memory (inside the CPU) that can be accessed directly
by the processor.

Secondary storage is the alternative storage in a
computer. It is an external storage that refers to various ways a computer can store program and data.

PRIMARY STORAGE

Primary storage is the main memory in a computer. It stores data and programs that can be accessed directly by the processor.

TYPES OF PRIMARY STORAGE
There are two types of primary storage which are RAM and ROM.

RAM is an acronym for Random-Access Memory which means the data and program in RAM can beread and written.

ROM is an acronym for Read-Only Memory. The data or program in ROM can just be read but cannot be written at all.

RANDOM-ACCESS MEMORY (RAM)

RAM is installed inside computers. RAM is also known as a working memory.
The data in RAM can be read (retrieved) or written (stored).
RAM is volatile which means the programs and data in RAM are lost when the computer is powered off.
A computer uses RAM to hold temporary instructions and data needed to complete tasks. This enables the computer's CPU (Central Processing Unit) to access instructions and data stored in the memory very quickly.
RAM stores data during and after processing.

READ-ONLY MEMORY (ROM)

ROM is another type of memory permanently stored inside the computer.
ROM is non-volatile. It holds the programs and data when the computer is powered off.
Programs in ROM have been pre-recorded. It can only be stored by the manufacturer; once it is done, it cannot be changed.
Many complex functions, such as start up operating instructions, translators for high-level languages and operating systems are placed in ROM memory.
All the contents in ROM can be accessed and read but cannot be changed.

SECONDARY STORAGE

WHAT IS SECONDARY STORAGE?

Secondary storage is another alternative storage to keep your work and documents. It is very useful to store programs and data for future use.

It is non-volatile, which means that it does not need power to maintain the information stored in it. It will store the information until it is erased.

TYPES OF SECONDARY STORAGE

MAGNETIC MEDIUM
Magnetic Medium is a non-volatile storage medium. It can be any type of storage medium that utilizes magnetic patterns to represent information. The devices use disks that are coated with magnetically sensitive material. The examples of magnetic storage are:
magnetic disk such as:
o a floppy disk, used for off-line storage
o hard disk, used for secondary storage
magnetic tape; including video cassette, audio storage reel-to-reel tape and others.

OPTICAL MEDIUM

Optical Medium is a non-volatile storage media that holds content in digital form that are written and read by a laser. These media include various types of CDs and DVDs.

These following forms are often commonly used :

CD, CD-ROM, and DVD: Read only storage, used for distribution of digital information such as music, video and computer programs.

CD-R: Write once storage, the data cannot be erased or written over once it is saved.

CD-RW, DVD-RW, and DVD-RAM: Slow to write but fast reading storage; it allows data that have been saved to be erased and rewritten.

FLASH MEMORY

Flash Memory is a solid-state, non-volatile, rewritable memory that functions like RAM and a hard disk drive combined. Flash memory store bits of electronic data in memory cells just like DRAM (Dynamic RAM), but it also works like a hard disk drive that when the power is turned off, the data remains in the memory. Flash memory cards and flash memory sticks are examples of flash memory.

Flash memory cards are also used with digital cellular phones, MP3 players, digital video cameras and other portable digital devices.

Flash memory is also called USB drives, thumb drives, pen drives or flash drives

The advantages of flash memory are, it offers fast reading access times among the secondary storage devices, (though not as fast as RAM) it is durable and requires low voltage. It is also light and small. The disadvantage is, it is more expensive than the magnetic disk of the same capacity.