Saturday, April 7, 2012

Hardware and Software, Input and Output devices And storage

What is Hardware ?

A device connecting or related to computers that can be touched and felt by the user is called a hardware.

Keyboard, mouse, printer, speakers and so on are examples of hardware.

What is Software ?

A program installed on the computer or which can be used in storable form which cannot be touched or felt by the user is called a software. All operating systems are softwares. All other programs installed on that operating system are called software.

What is an Input Device ?

In computing, an input device is any peripheral (piece of computer hardware equipment) that collects data from the  user and sends it to the cpu for processing.

Examples are mouse, keyboard, scanner and microphones.

What is an Output device ?

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.

Examples are monitor and speakers.

What is Storage ?

A storage is a place in the computer in which a user can store and remove data. This place is called the hard disk drive. This is called a ROM (Read Only Memory) and is a source of permanent storage and can be deleted by the user. A storage can also be in the form of memory which is called RAM (Random Access Memory). As the name suggests, it holds data temporarily until being saved in ROM permanently. As RAM stores data temporarily, if the data is not stored in ROM, the data is deleted when the power is turned off.

What are the units of Storage ?


The common units of storage are KB (Kilo Byte), MB (Mega Byte), GB (Gigabyte) and TB (Terabyte).


1 MB =1000 KB


1 GB = 1000 MB1 


TB = 1024 GB

What are the Sources of storage ?

Hard Disk: A hard disk drive (HDD; also hard drive, hard disk, or disk drive) is a device for storing and retrieving digital information, primarily computer data. It consists of one or more rigid (hence "hard") rapidly rotating discs (often referred to as platters), coated with magnetic material and with magnetic headsarranged to write data to the surfaces and read it from them.

Hard drives are classified as non-volatile, random access, digital, magnetic, data storage devices. Introduced by IBM in 1956, hard disk drives have decreased in cost and physical size over the years while dramatically increasing in capacity and speed.
Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s. They have maintained this position because advances in their recording capacity, cost, reliability, and speed have kept pace with the requirements for secondary storage.


CD (Compact Disk)
he Compact Disc (also known as a CD) is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but the format was later adapted for storage of data (CD-ROM), write-once audio and data storage (CD-R), rewritable media (CD-RW), Video Compact Discs (VCD), Super Video Compact Discs (SVCD), PhotoCD, PictureCD, CD-i, and Enhanced CD. Audio CDs and audio CD players have been commercially available since October 1982.
Standard CDs have a diameter of 120 millimetres (4.7 in) and can hold up to 80 minutes of uncompressed audio or 700 MB (700 × 220 bytes) of data. TheMini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they are sometimes used for CD singles, storing up to 24 minutes of audio or delivering device drivers.

CD-ROMs and CD-Rs remain widely used technologies in the computer industry. The CD and its extensions are successful: in 2004, worldwide sales of CD audio, CD-ROM, and CD-R reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide.[1] Compact Discs are increasingly being replaced or supplemented by other forms of digital distribution and storage, such as downloading and flash drives, with audio CD sales dropping nearly 50% from their peak in 2000.


DVD
DVD is an optical disc storage format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity thanCompact Discs while having the same dimensions.
Pre-recorded DVDs are mass-produced using molding machines that physically stamp data onto the DVD. Such discs are known as DVD-ROM, because data can only be read and not written nor erased. Blank recordable DVD discs (DVD-R and DVD+R) can be recorded once using a DVD recorder and then function as a DVD-ROM. Rewritable DVDs (DVD-RW, DVD+RW, and DVD-RAM) can be recorded and erased multiple times.
DVDs are used in DVD-Video consumer digital video format and in DVD-Audio consumer digital audio format, as well as for authoring AVCHD discs. DVDs containing other types of information may be referred to as DVD data discs.
A DVD looks similar to a CD and its storage capacity varies from 4.7 GB to 8.0 GB

Blu Ray Disc
Blu-ray Disc (official abbreviation BD) is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB[ambiguous] per layer, with dual layer discs (50 GB) being the norm for feature-length video discs. Triple layer discs (100 GB) and quadruple layers (128 GB) are available for BD-XL re-writer drives.[2]
The major application of Blu-ray Discs is as a medium for video material such as feature films. Besides the hardware specifications, Blu-ray Disc is associated with a set of multimedia formats. Generally these formats allow for the video and audio to be stored with greater definition than on DVD.
The first Blu-ray Disc prototypes were unveiled in October 2000, and the first prototype player was released in April 2003 in Japan. Afterwards, it continued to be developed until its official release in June 2006.
The name Blu-ray Disc refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.
The format was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2011, more than 2,500 Blu-ray Disc titles were available in Australia and the United Kingdom, with 3,500 in the United States and Canada.[3] In Japan, as of July 2010, more than 3,300 titles have been released.[4]
During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the main company that supported HD DVD, conceded in February 2008,[5] releasing its own Blu-ray Disc player in late 2009.


A blu ray disc looks similar to a DVD and a CD


VCD

Before the advent of DVD and Blu-ray, the Video CD (abbreviated as VCD, and also known as View CD, Compact Disc digital video) became the first format for distributing films on standard 120 mm optical discs. The format is a standard digital format for storing video on a Compact Disc. VCDs are playable in dedicated VCD players, most DVD-Video players, personal computers, and some video game consoles.
The VCD standard was created in 1993[1][2] by Sony, Philips, Matsushita, and JVC and is referred to as the White Book standard. Though supplanted by the two aforementioned formats, VCDs are still popular, particularly in the low cost market.
A VCD looks similar to a CD, DVD, and a Blu Ray Disc and can store data up to 700 MB.

USB (Universal Serial Bus) Flash Drive
A small, portable flash memory card that plugs into a computer USBport and functions as a portable hard drive. USB flash drives are touted as being easy-to-use as they are small enough to be carried in a pocket and can plug into any computer with a USB drive. USB flash drives have less storage capacity than an external hard drive, but they are smaller and more durable because they do not contain any internal moving parts.

Memory Cards

A memory card or flash card is an electronic flash memory data storage device used for storing digital information. They are commonly used in many electronic devices, including digital cameras, mobile phones, laptop computers, MP3 players, and video game consoles. They are small, re-recordable, and able to retain data without power.



Friday, April 6, 2012

Mikes and microphones


.A microphone (colloquially called a mic or mike; both pronounced /ˈmaɪk/[1]) is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recordedaudio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors.
Most microphones today use electromagnetic induction (dynamic microphone), capacitance change (condenser microphone), piezoelectric generation, or light modulation to produce an electrical voltage signal from mechanical vibration.
Mikes are mainly used during voice projects and video calls or video chats

Speakers



Computer speakers, or multimedia speakers, are speakers external to a computer, that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.5 mm (approximately 1/8 inch) stereo jack plug often color-coded lime green (following the PC 99 standard) for computer sound cards. A plug and socket for a two-wire (signal and ground) coaxial cable is widely used to connect analog audio and video components. Rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8" thick by 5/16" long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 500 milliamps provided by the USB port, allowing about 2.5 watts of output power.
Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small, plastic, and have mediocre sound quality. Some computer speakers have equalization features such as bass and treble controls.
Some computer displays have rather basic speakers built-in. Laptops come with integrated speakers. Restricted space available in laptops means these speakers usually produce low-quality sound.
For some users, a lead connecting computer sound output to an existing stereo system is practical. This normally yields much better results than small low-cost computer speakers. Computer speakers can also serve as an economy amplifier for MP3 player use for those who wish to not use headphones, although some models of computer speakers have headphone jacks of their own.


Mice and keyboards

Mouse

A mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons. It sometimes features other elements, such as "wheels", which allow the user to perform various system-dependent operations, or extra buttons or features that can add more control or dimensional input. The mouse's motion typically translates into the motion of a pointer on a display, which allows for fine control of a graphical user interface.


Keyboard


In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input device for computers.
Despite the development of alternative input devices, such as the mouse, touchscreen, pen devices, character recognition and voice recognition, the keyboard remains the most commonly used and most versatile device used for direct (human) input into computers.
A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence. While most keyboard keys produce letters, numbers or signs (characters), other keys or simultaneous key presses can produce actions or computer commands.
In normal usage, the keyboard is used to type text and numbers into a word processor, text editor or other program. In a modern computer, the interpretation of key presses is generally left to the software. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as Windows'Control-Alt-Delete combination, which brings up a task window or shuts down the machine. Keyboards are the only way to enter commands on a command-line interface.

Printers and Scanners

Printers

In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source. In addition, a few modern printers can directly interface to electronic media such as memory cards, or to image capture devices such as digital cameras and scanners; some printers are combined with scanners or fax machines in a single unit, and can function as photocopiers. Printers that include non-printing features are sometimes called multifunction printers (MFP), multi-function devices (MFD), or all-in-one (AIO) printers. Most MFPs include printing, scanning, and copying among their many features.

Scanners


In computing, an image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.
Modern scanners typically use a charge-coupled device (CCD) or a Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use aphotomultiplier tube as the image sensor. A rotary scanner, used for high-speed document scanning, is another type of drum scanner, using a CCD array instead of a photomultiplier. Other types of scanners are planetary scanners, which take photographs of books and documents, and 3D scanners, for producing three-dimensional models of objects.
Another category of scanner is digital camera scanners, which are based on the concept of reprographic cameras. Due to increasing resolution and new features such as anti-shake, digital cameras have become an attractive alternative to regular scanners. While still having disadvantages compared to traditional scanners (such as distortion, reflections, shadows, low contrast), digital cameras offer advantages such as speed, portability and gentle digitizing of thick documents without damaging the book spine. New scanning technologies are combining 3D scanners with digital cameras to create full-color, photo-realistic 3D models of objects





Web Cameras


A webcam is a video camera that feeds its images in real time to a computer or computer network, often via USB, ethernet, or Wi-Fi.
Their most popular use is the establishment of video links, permitting computers to act as videophones or videoconference stations. The common use as avideo camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance, computer vision, video broadcasting and for recording social videos .
Webcams are known for their low manufacturing cost and flexibility,[1] making them the lowest cost form of videotelephony. They have also become a source of security and privacy issues, as some built-in webcams can be remotely activated via spyware.
The best web cameras are the highly definite ones (high definition) and the best selling web cameras are from Microsoft and Logitech.




Joysticks and Analog Sticks

The Joystick

joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or side-stick. They often have supplementary switches on them to control other aspects of the aircraft's flight.
Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick. 
Joysticks are of three types :
Competition - The Competition joystick is most comfortable joystick.  It's a microswitch based joystick with a smooth 360 degree circular motion, meaning you can't feel any "corners" as you move it 360 degrees.
This joystick comes in 5 different colors: Black, Red, Blue, Green and Yellow. Image is in the left side

Perfect 360 - The Perfect 360 from Happ Controls uses an optical sensor to sense which direction you are  moving the joystick rather than microswitches.  It's a very quiet and precise joystick with smooth 360 degrees of motion.  The only draw back with this joystick, besides the price, is it comes stock with a fairly tight spring making it tiresome to use for long periods for some people.  This joystick only comes in black. Image is below this text.

Sanwa JLF - The Sanwa JLF Joystick offers quick response and a ball top.  This is the preferred joystick in Japan and many U.S. players have adopted this joystick because of it's precise movement and quick reaction time.  The default joystick comes with a square gate that really lets you know when you are at a diaganol.  The optional Octogon gate makes the joystick more fluid in a 360 degree motion.Image is below this text.

The Analog Stick

An analog stick, sometimes called a control stick or thumbstick, is an input device for a controller (often a game controller) that is used for two-dimensional input. An analog stick is a variation of a joystick, consisting of a protrusion from the controller; input is based on the position of this protrusion in relation to the default "center" position. While digital sticks rely on single electrical connections for movement (using internal digital electrical contacts for up, down, left and right), analog sticks use continuous electrical activity running through potentiometers. The analog stick has greatly overtaken the D-pad in both prominence and usage in console video games.
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