World Library  
Flag as Inappropriate
Email this Article

Personal digital assistant

Article Id: WHEBN0000023304
Reproduction Date:

Title: Personal digital assistant  
Author: World Heritage Encyclopedia
Language: English
Subject: Enterprise digital assistant, CLIÉ, Handwriting recognition, Tablet computer, USB
Collection: Information Appliances, Mobile Computers, Personal Digital Assistants, Time Management
Publisher: World Heritage Encyclopedia

Personal digital assistant

The Palm TX

A personal digital assistant (PDA), also known as a palmtop computer, or personal data assistant,[1][2][3] is a mobile device that functions as a personal information manager. The term evolved from Personal Desktop Assistant, a software term for an application that prompts or prods the user of a computer with suggestions or provides quick reference to contacts and other lists. PDAs were discontinued in early 2010s after the widespread adoption of smartphones.[4]

Nearly all PDAs have the ability to connect to the Internet. A PDA has an electronic visual display, enabling it to include a web browser, all models also have audio capabilities enabling use as a portable media player, and also enabling most of them to be used as mobile phones. Most PDAs can access the Internet, intranets or extranets via Wi-Fi or Wireless Wide Area Networks. Most PDAs employ touchscreen technology.

The first PDA was released in 1984 by Psion's Series 3, in 1991, which began to resemble the more familiar PDA style. It also had a full keyboard.[5][6] 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.[7] In 1994, IBM introduced the first PDA with full mobile phone functionality, the IBM Simon, which can also be considered the first smartphone. Then in 1996, Nokia introduced a PDA with full mobile phone functionality, the 9000 Communicator, which became the world's best-selling PDA. The Communicator spawned a new category of PDAs: the "PDA phone", now called "smartphone". Another early entrant in this market was Palm, with a line of PDA products which began in March 1996.


  • Typical features 1
    • Touch screen 1.1
    • Memory cards 1.2
    • Wired connectivity 1.3
    • Wireless connectivity 1.4
    • Synchronization 1.5
      • Wireless synchronization 1.5.1
  • Operating systems of PDAs 2
  • Automobile navigation 3
  • Ruggedized PDAs 4
  • Medical and scientific uses 5
  • Educational uses 6
    • Recreational uses 6.1
  • Lists of PDAs 7
    • Consumer PDAs 7.1
    • Rugged PDAs 7.2
  • See also 8
  • References 9
  • External links 10

Typical features

A typical PDA has a touchscreen for entering data, a memory card slot for data storage, and IrDA, Bluetooth and/or Wi-Fi. However, some PDAs may not have a touch screen, using softkeys, a directional pad, and a numeric keypad or a thumb keyboard for input; this is typically seen on telephones that are incidentally PDAs.

In order to have the functions expected of a PDA, a device's software typically includes an appointment calendar, a to-do list, an address book for contacts, a calculator, and some sort of memo (or "note") program. PDAs with wireless data connections also typically include an email client and a Web browser.

Touch screen

Many of the original PDAs, such as the Apple Newton and Palm Pilot, featured a touchscreen for user interaction, having only a few buttons—usually reserved for shortcuts to often-used programs. Some touchscreen PDAs, including Windows Mobile devices, had a detachable stylus to facilitate making selections. The user interacts with the device by tapping the screen to select buttons or issue commands, or by dragging a finger (or the stylus) on the screen to make selections or scroll.

Typical methods of entering text on touchscreen PDAs include:

  • A virtual keyboard, where a keyboard is shown on the touchscreen. Text is entered by tapping the on-screen keyboard with a finger or stylus.
  • An external keyboard connected via USB, Infrared port, or Bluetooth. Some users may choose a chorded keyboard for one-handed use.
  • Handwriting recognition, where letters or words are written on the touchscreen, and the PDA converts the input to text. Recognition and computation of handwritten horizontal and vertical formulas, such as "1 + 2 =", may also be a feature.
  • Stroke recognition allows the user to make a predefined set of strokes on the touchscreen, sometimes in a special input area, representing the various characters to be input. The strokes are often simplified character shapes, making them easier for the device to recognize. One widely known stroke recognition system is Palm's Graffiti.

Despite rigorous research and development projects, end-users experience mixed results with handwriting recognition systems. Some find it frustrating and inaccurate, while others are satisfied with the quality of the recognition.[8]

Touchscreen PDAs intended for business use, such as the BlackBerry and Palm Treo, usually also offer full keyboards and scroll wheels or thumbwheels to facilitate data entry and navigation.

Many touchscreen PDAs support some form of external keyboard as well. Specialized folding keyboards, which offer a full-sized keyboard but collapse into a compact size for transport, are available for many models. External keyboards may attach to the PDA directly, using a cable, or may use wireless technology such as infrared or Bluetooth to connect to the PDA.

Newer PDAs, such as the HTC HD2, Apple iPhone, Apple iPod Touch, and Palm Pre, Palm Pre Plus, Palm Pixi, Palm Pixi Plus, Google Android (operating system) include more advanced forms of touchscreen that can register multiple touches simultaneously. These "multi-touch" displays allow for more sophisticated interfaces using various gestures entered with one or more fingers.

Memory cards

Although many early PDAs did not have memory card slots, now most have either some form of Secure Digital (SD) slot or a CompactFlash slot. Although designed for memory, Secure Digital Input/Output (SDIO) and CompactFlash cards are available that provide accessories like Wi-Fi or digital cameras, if the device can support them. Some PDAs also have a USB port, mainly for USB flash drives. Some PDAs use microSD cards, which are electronically compatible with SD cards, but have a much smaller physical size.

Wired connectivity

While early PDAs connected to a user's personal computer via serial ports or another proprietary connection, many today connect via a USB cable. Older PDAs were unable to connect to each other via USB, as their implementations of USB didn't support acting as the "host".

Some early PDAs were able to connect to the Internet indirectly by means of an external modem connected via the PDA's serial port or "sync" connector,[9] or directly by using an expansion card that provided an Ethernet port.

Wireless connectivity

Most modern PDAs have Bluetooth, a popular wireless protocol for mobile devices. Bluetooth can be used to connect keyboards, headsets, GPS receivers, and other nearby accessories. It's also possible to transfer files between PDAs that have Bluetooth.

Many modern PDAs have Wi-Fi wireless network connectivity and can connect to Wi-Fi hotspots.[10] All smartphones, and some other modern PDAs, can connect to Wireless Wide Area Networks, such as those provided by cellular telecommunications companies.

Older PDAs from the 90s to 2006 typically had an IrDA (infrared) port allowing short-range, line-of-sight wireless communication. Few current models use this technology, as it has been supplanted by Bluetooth and Wi-Fi. IrDA allows communication between two PDAs, or between a PDA and any device with an IrDA port or adapter. Some printers have IrDA receivers,[11] allowing IrDA-equipped PDAs to print to them, if the PDA's operating system supports it. Universal PDA keyboards designed for these older PDAs use infrared technology. Infrared technology is low-cost and has the advantage of being allowed aboard.


Most PDAs can synchronize their data with applications on a user's computer. This allows the user to update contact, schedule, or other information on their computer, using software such as Microsoft Outlook or ACT!, and have that same data transferred to PDA—or transfer updated information from the PDA back to the computer. This eliminates the need for the user to update their data in two places.

Synchronization also prevents the loss of information stored on the device if it is lost, stolen, or destroyed. When the PDA is repaired or replaced, it can be "re-synced" with the computer, restoring the user's data.

Some users find that data input is quicker on their computer than on their PDA, since text input via a touchscreen or small-scale keyboard is slower than a full-size keyboard. Transferring data to a PDA via the computer is therefore a lot quicker than having to manually input all data on the handheld device.

Most PDAs come with the ability to synchronize to a computer. This is done through synchronization software provided with the handheld, or sometime with the computer's operating system. Examples of synchronization software include:

  • HotSync Manager, for Palm OS PDAs
  • 'Microsoft ActiveSync, used by Windows XP and older Windows operating systems to synchronize with Windows Mobile, Pocket PC, and Windows CE PDAs, as well as PDAs running iOS, Palm OS, and Symbian
  • Microsoft Windows Mobile Device Center for Windows Vista, which supports Microsoft Windows Mobile and Pocket PC devices.
  • Apple iTunes, used on Mac OS X and Microsoft Windows to sync iOS devices (such as the iPhone and iPod touch)
  • iSync, included with Mac OS X, can synchronize many SyncML-enabled PDAs
  • BlackBerry Desktop Software, used to sync BlackBerry devices.

These programs allow the PDA to be synchronized with a personal information manager, which may be part of the computer's operating system, provided with the PDA, or sold separately by a third party. For example, the RIM BlackBerry comes with RIM's Desktop Manager program, which can synchronize to both Microsoft Outlook and ACT!.

Other PDAs come only with their own proprietary software. For example, some early Palm OS PDAs came only with Palm Desktop, while later Palm PDAs—such as the Treo 650—have the ability to sync to Palm Desktop or Microsoft Outlook. Microsoft's ActiveSync and Windows Mobile Device Center only synchronize with Microsoft Outlook or a Microsoft Exchange server.

Third-party synchronization software is also available for some PDAs from companies like CommonTime[12] and CompanionLink.[13] Third-party software can be used to synchronize PDAs to other personal information managers that are not supported by the PDA manufacturers (for example, GoldMine and IBM Lotus Notes).

Wireless synchronization

Some PDAs can synchronize some or all of their data using their wireless networking capabilities, rather than having to be directly connected to a personal computer via a cable.

Apple iOS devices, like the iPhone, iPod Touch, and iPad, can use Apple's iCloud service (formerly MobileMe) to synchronize calendar, address book, mail account, Internet bookmark, and other data with one or more Macintosh or Windows computers using Wi-Fi or cellular data connections.[14]

Devices running Palm's webOS or Google's Android operating system primarily sync with the cloud. For example, if Gmail is used, information in contacts, email, and calendar can be synchronized between the phone and Google's servers.

RIM sells BlackBerry Enterprise Server to corporations so that corporate BlackBerry users can wirelessly synchronize their PDAs with the company's Microsoft Exchange Server, IBM Lotus Domino, or Novell GroupWise servers.[15] Email, calendar entries, contacts, tasks, and memos kept on the company's server are automatically synchronized with the BlackBerry.[16]

Operating systems of PDAs

The most common operating systems pre-installed on PDAs are:

Other, rarely used operating systems:

  • EPOC, then Symbian OS (in mobile phone + PDA combos)
  • Linux (e.g. VR3, iPAQ,[17] Sharp Zaurus PDA, Opie, GPE, Familiar Linux[18] etc.)
  • Newton
  • QNX (also on iPAQ)

Automobile navigation

Some PDAs include Global Positioning System (GPS) receivers; this is particularly true of smartphones. Other PDAs are compatible with external GPS-receiver add-ons that use the PDA's processor and screen to display location information.[19]

PDAs with GPS functionality can be used for automotive navigation. PDAs are increasingly being fitted as standard on new cars.

PDA-based GPS can also display traffic conditions, perform dynamic routing, and show known locations of roadside mobile radar guns. TomTom, Garmin, and iGO offer GPS navigation software for PDAs.

Ruggedized PDAs

Some businesses and government organizations rely upon rugged PDAs, sometimes known as enterprise digital assistants (EDAs), for mobile data applications. EDAs often have extra features for data capture, such as barcode readers, radio-frequency identification (RFID) readers, magnetic stripe card readers, or smart card readers.

Typical applications include:

  • military: notably U.S. Army
  • supply chain management in warehouses
  • package delivery
  • route accounting
  • medical treatment and recordkeeping in hospitals
  • facilities maintenance and management
  • parking enforcement
  • access control and security
  • capital asset maintenance
  • meter reading by utilities
  • "wireless waitress" applications in restaurants and hospitality venues
  • infection control audit and surveillance within healthcare environments
  • taxicab allocation and routing.

Medical and scientific uses

Many companies have developed PDA products aimed at the medical profession's unique needs, such as drug databases, treatment information, and medical news. Services such as ward rounds. Pendragon and Syware provide tools for conducting research with, allowing the user to enter data into a centralized database using their PDA. Microsoft Visual Studio and Sun Java also provide programming tools for developing survey instruments on the handheld. These development tools allow for integration with SQL databases that are stored on the handheld and can be synchronized with a desktop- or server-based database.

PDAs have been shown to aid diagnosis and drug selection and some studies have concluded that when patients use PDAs to record their symptoms, they communicate more effectively with hospitals during follow-up visits.

The development of Sensor Web technology may lead to wearable bodily sensors to monitor ongoing conditions, like diabetes or epilepsy, which would alert patients and doctors when treatment is required using wireless communication and PDAs.

Educational uses

As mobile technology becomes more common, it is increasingly being used as a learning tool. Some educational institutions have embraced M-Learning, integrating PDAs into their teaching practices.

PDAs and handheld devices are allowed in many classrooms for digital note-taking. Students can spell-check, modify, and amend their class notes on the PDA. Some educators distribute course material through the Internet or infrared file-sharing functions of the PDA. Textbook publishers have begun to release e-books, or electronic textbooks, which can be uploaded directly to a PDA, reducing the number of textbooks students must carry.[20]

Software companies have developed PDA programs to meet the instructional needs of educational institutions, such as dictionaries, thesauri, word processing software, encyclopedias, and digital lesson planners.

Recreational uses

PDAs may be used by music enthusiasts to play a variety of music file formats. Many PDAs include the functionality of an MP3 player.

Road rally enthusiasts can use PDAs to calculate distance, speed, and time. This information may be used for navigation, or the PDA's GPS functions can be used for navigation.

Underwater divers can use PDAs to plan breathing gas mixtures and decompression schedules using software such as "V-Planner."

As of today, any smartphone can do this as well.

Lists of PDAs

Consumer PDAs

Rugged PDAs

See also


  1. ^ Kot, Chelsea (July 11, 2011). "A Brief History of Tablets and Tablet Cases". Tablets2Cases. Retrieved December 10, 2011. 
  2. ^ Viken, Alexander (April 10, 2009). "The History of Personal Digital Assistants 1980 – 2000". Agile Mobility. Retrieved February 18, 2011. 
  3. ^ "History of the HP 95LX computer". HP Virtual Museum. Hewlett-Packard. Retrieved February 18, 2011. 
  4. ^ Andrew Smith, Faithe Wempen (2011). CompTIA Strata Study Guide. John Wiley & Sons. p. 140.  
  5. ^ "The Protea Story". The Register. 
  6. ^ History of Psion
  7. ^ Newton, Reconsidered - Time magazine, June 1, 2012
  8. ^ Handwriting recognition accuracy:
    • Kahney, Leander (August 29, 2002). "Apple's Newton Just Won't Drop". Wired. Condé Nast Publications. Retrieved August 21, 2010. 
    • Ringel, Edward (1997), "Newton? Get Serious!", MacTech Magazine 13 (4), Software,  
    • Blickenstorfer, Conrad M. (June 2000), From the editor: Commentary by Pen Computing Magazine's editor-in-chief (34), I have used [handwriting recognition] for years, taking notes during lectures and often writing whole articles while on airplanes. 
    • See user testing results discussed in part 6 of: Yaeger, Larry S; Webb, Brandyn J; Lyon, Richard F. "Combining Neural Networks and Context-Driven Search for On-Line, Printed Handwriting Recognition in the Newton" (PDF). A.I. Magazine. 
    • Mayer, Don (July 1, 1997). "Kibbles&Bytes #29: Don's Review of the Newton Message Pad 2000". Small Dog Electronics. Archived from the original on April 16, 2008. Retrieved February 18, 2011. 
    • Klingsporn, Geoffrey (May 1997). "The Postgraduate Newton: a month in academia with Apple's new handheld computer". The History and Macintosh Society. note-taking. Retrieved August 21, 2010. 
    • Wittmann, Michael C. "What's Right With The Newton: Part I: Handwriting recognition". Retrieved August 21, 2010. 
  9. ^ Patrick (December 14, 2006). "Palm PDA Cables". DeepWave. Retrieved August 21, 2010. 
  10. ^ "MC55A0 Rugged Wi-Fi Enterprise Mobile Computer". Retrieved January 26, 2013. 
  11. ^ For example: "HP LaserJet 5P and 5MP Printers — Product Specifications". HP Business Support Center. Hewlett-Packard. Retrieved August 21, 2010. 
  12. ^ CommonTime
  13. ^ CompanionLink
  14. ^ Mobileme#iOS
  15. ^ "BlackBerry — Enterprise Server — BlackBerry BES Server". Research In Motion. Retrieved August 21, 2010. 
  16. ^ "BlackBerry — Business Software Features". Research In Motion. Retrieved August 21, 2010. 
  17. ^ Ernest Khoo: Alternative operating systems on your PDA
  18. ^ HAZIMIN SULAIMAN: Highlights: Knowing the differences in PDA operating systems (2005)
  19. ^ "Palm Support: Palm GPS Navigator 3207NA". Retrieved August 21, 2010. 
  20. ^ "10 tips to save on college textbooks". Centre Daily Times. August 20, 2010. Retrieved August 21, 2010. 
  21. ^ Roland PMA-5
  22. ^ Catchwell
  23. ^ M3 Mobile
  24. ^ Pidion
  25. ^ Two Technologies, Inc.
  26. ^ Unitech

External links

  • Annotated bibliography of references to gesture and pen computing
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.