iPad

The iPad is a tablet computer designed and developed by Apple. It is particularly marketed as a platform for audio and visual media such as books, periodicals, movies, music, and games, as well as web content. At about 1.5 pounds (680 grams), its size and weight are between those of most contemporary smarphones and laptop computers. Apple released the iPad in April 2010, and sold 3 million of the devices in 80 days.

According to a report released by Strategy Analytics, the Apple iPad has gained a 95 percent share sales of Tablet PC at the end of second quarter 2010. And during the second quarter 2010, Apple had sold 4.19 million iPads around the world.

The iPad runs the same operating system as the earlier iPod Touch and iPhone. It can run its own applications as well as ones developed for the iPhone. Without modification, it will only run programs approved by Apple and distributed via its online store.

Like iPhone and iPod Touch, the iPad is controlled by a multitouch display — a break from most previous tablet computers, which used a pressure-triggered stylus. The iPad uses a Wi-Fi data connection to browse the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The device is managed and synced by iTunes on a personal computer via USB cable.

Media reaction to the device has generally been neutral or positive, with more positive reaction after the device was launched.

History

Apple's first tablet computer was the Newton  MessagePad 100, introduced in 1993, which led to the creation of the ARM6processor core with Acorn Compuers. Apple also developed a prototype PowerBook Duo-based tablet, the PenLite, but in order to avoid hurting MessagePad sales did not sell it. Apple released several more Newton-based PDAs, and discontinued the last, theMessagePad 2100, in 1998.

With the success of the introduction of portable music player iPod  in 2001, Apple re-entered the mobile-computing market in 2007 with the iPhone . Smaller than the iPad but featuring a camera and mobile phone, it pioneered the multitouch finger-sensitive touchscreen interface of Apple's mobile operating system—iOS. By late 2009, the iPad's release had been rumored for several years. Mostly referred to as "Apple's tablet", iTablet and iSlate were among the speculated names. The iPad was announced on January 27, 2010 by Steve Jobs at an Apple press conference at the Yerba Buena Center for the Arts in San Francisco.

Jobs later admitted that the iPad was developed before the iPhone. Upon realizing that it would work just as well as a mobile phone, Jobs put development of the iPad on hold and decided to develop the iPhone instead.

Screen and input

The iPad's touchscreen display is a 9.7 in (25 cm) liquid crystal display (1024 × 768 pixels) with fingerprint-resistant and scratch-resistant glass. Like the iPhone, the iPad is designed to be controlled by bare fingers; normal gloves and styli that prevent electrical conductivity may not be used, although there are special gloves and capacitive styli designed for this use.

The display responds to two other sensors: an ambient light sensor to adjust screen brightness and a 3-axis accelermeter to sense iPad orientation and switch between portrait and landscape modes. Unlike the iPhone and iPod touch built-in applications, which work in three orientations (portrait, landscape-left and landscape-right), the iPad built-in applications support screen rotationin all four orientations (the three aforementioned ones along with upside-down), meaning that the device has no intrinsic "native" orientation; only the relative position of the home button changes.

The iPad has a switch to lock out the screen rotation function (reportedly to prevent unintended rotation when the user is lying down). There are a total of four physical switches, including a home button below the display that returns the user to the main menu, and three plastic physical switches on the sides: wake/sleep and volume up/down, along with the screen rotation lock.

Ars Technica noted the similarity between the iPad and Star Trek's fictional PADD tablet computer, both in name and functionality.

Connectivity

Steve Jobs, Apple CEO, introducing the iPad

The iPad can use Wi-Fi network trilateration from Skyhook Wireless to provide location information to applications such as Google Map. The 3G model contains A-GPS to allow its position to be calculated with GPS or relative to nearby cellphone towers; it also has a black plastic accent on the back side to improve 3G radio sensitivity.

For wired connectivity, the iPad has the proprietary Apple Dock Connector; it lacks the Ethernet of larger computers, and USB of mobile devices.

Audio and output

Back of the iPad 3G

The iPad has two internal speakers that push mono sound through two small sealed channels to the three audio ports carved into the bottom-right of the unit. A volume switch is on the right side of the unit.

A 3.5-mm TRS connector audio-out jack on the top-left corner of the device provides stereo sound for headphones with or without microphones and/or volume controls. The iPad also contains a microphone that can be used for voice recording.

The built-in Bluetooth 2.1 + EDR interface allows wireless headphones and keyboards to be used with the iPad. However, the iOS does not currently support file transfer via Bluetooth. iPad also features 1024 x 768 VGA video output for connecting an external display or television.

Applications

The iPad comes with several applications, including Safari, Mail, Photos, Video, YouTube, iPod, iTunes, App Store, iBooks, Maps, Notes, Calendar, Contacts, and Spotlight Search. Several are improved versions of applications developed for the iPhone.

The iPad syncs with iTunes on a Mac or Windows PC. Apple ported its iWork suite from the Mac to the iPad, and sells pared down versions of Pages, Number, and Keytone apps in the App Store. Although the iPad is not designed to replace a mobile phone, a user can use a wired headset or the built-in speaker and microphone and place phone calls over Wi-Fi or 3G using a VoIP application. The iPad has lots of third party applications available for it; as of September 1, 2010 there were 25000 iPad specific apps on the AppStore.