Mobile Computing

A personal digital assistant (PDA), also known as a palmtop computer, is a mobile device which functions as a personal information manager and has the ability to connect to the internet. The PDA has an electronic visual display enabling it to include a web browser, but some newer models also have audio capabilities, enabling them to be used as mobile phones or portable media players. Many PDAs can access the internet, intranets or extranets via Wi-Fi, or Wireless Wide Area Networks (WWANs). Many PDAs employ touch screen technology.

The term PDA was first used on January 7, 1992, by Apple Computer CEO John Sculley at the Consumer Electronics Show in Las Vegas, Nevada, referring to the Apple Newton. In 1996, Nokia introduced the first mobile phone with full PDA functionality, the 9000 Communicator, which has since grown to become the world’s best-selling PDA and which spawned a category of phones called the smartphone. Today the vast majority of all PDAs are smartphones, selling over 150 million units while non-phone (“stand-alone”) PDAs sell only about 3 million units per year. HTC, Apple, Palm, Nokia N-Series, and RIM BlackBerry are typical smartphone brands.

Currently, a typical PDA has touch screen for entering data, a memory card slot for data storage and at least one of the following for connectivity: IrDA, Bluetooth and/or WiFi. However, many PDAs (typically those used primarily as telephones) may not have a touch screen, using softkeys, a directional pad and either the numeric keypad or a thumb keyboard for input.

Software typically required to be a PDA includes an appointment calendar, a to-do list, an address book for contacts and some sort of note program. Connected PDAs also typically include E-mail and Web support.

Many of the original PDAs, such as the Apple Newton and Palm Pilot, featured touchscreen for user interaction, having only a few buttons usually reserved for shortcuts to often used programs. Touch screen PDAs, including Windows Mobile devices, usually have a detachable stylus that can be used on the touch screen. Interaction is then done by tapping the screen to activate buttons or menu choices, and dragging the stylus to, for example, highlight. Text input is usually done in one of four ways:

* Using a virtual keyboard, where a keyboard is shown on the touch screen. Input is done by tapping letters on the screen.
* Using external keyboard or chorded keyboard connected by USB, IR or Bluetooth.
* Using letter or word recognition, where letters or words are written on the touch screen, and then “translated” to letters in the currently activated text field. Despite rigorous research and development projects, end-users experience mixed results with this input method, with some finding it frustrating and inaccurate, while others are satisfied with the quality.[1] Recognition and computation of handwritten horizontal and vertical formulas such as “1 + 2 =” was also under development.
* Stroke recognition (one Palm implementation is called Graffiti). In this system a predefined set of strokes represents the various characters used in input. The user learns to draw these strokes on the screen or in an input area. The strokes are often simplified character shapes to make them easier for the device to recognize.

PDAs for business use, including the BlackBerry and Palm Treo, have full keyboards and scroll wheels or thumb wheels to facilitate data entry and navigation, in addition to supporting touch-screen input. There are also full-size foldable keyboards available that plug directly, or use wireless technology to interface with the PDA and allow for normal typing. BlackBerry has additional functionality, such as push-based email and applications.

Newer PDAs, such as the Apple iPhone, iPod Touch and Palm Pre include new user interfaces using other means of input. The iPhone and iPod touch uses a technology called Multi-touch, as does the Palm Pre and HTC HD2.

iPod Touch

Apple iPhone

Palm Pre

This entry was posted on Thursday, July 1st, 2010 at 9:05 pm and is filed under Mobile Computing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.