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Personal Digital Assistants

Personal Digital Assistants

Personal digital assistants (PDAs) are small, hand-held computers. They use a form of touch screen technology, using a light pen or stylus as an input device rather than a keyboard. In addition, a detachable keyboard or a voice recorder can be used. PDAs are versatile information processing appliances. They are used frequently as personal information managers (PIMs) to record telephone numbers, addresses, appointments, and to-do lists. Also, PDAs can synchronize with microcomputers to transfer e-mail, text documents, spreadsheets, files, or databases. Other types of PDAs incorporate an integrated modem to connect with the Internet or to dial-up another computer in order to transfer data.

Some PDAs use wireless communications technology, providing great mobility. This use of wireless technology allows companies to provide PDAs to their employees in situations where laptops would be unworkable.

Palmtops, which are small computers that fit in the palm of one's hand, are also referred to as PDAs. The difference between a PDA and Palmtop computer is that the PDAs are pen-based, using a stylus rather than a keyboard for input, while the palmtop uses a small, integrated keyboard.

In 1993 Apple Computer introduced the first PDA, which was called the Newton MessagePad. Rather than just storing handwritten words, Newton converted them into typescript. Early versions of Newton had limited success with this difficult process. Three years later, 3Com's Palm Computing introduced the revolutionary PalmPilot. In June 1998, Microsoft began shipping a scaled down Windows operating system for manufacturers of palm-sized PCs. Apple's Newton was later taken off the market.

PDA Features

Several factors should be considered before purchasing a PDA, including what application software the user wishes to run; which types of input devices (keyboard, light pen, touch screen, voice recorder) are available and desired by the user; whether the amount of memory, specifically random access memory (RAM) , and the life of the battery are sufficient for the user' needs; what size of the device is desired; and, of course, what price the user wants to pay. In 2001 prices for PDAs ranged from a low of $100 for a simple personal information manager to more than $1,000 for full-screen PDAs with integrated keyboards.

Other features available in PDAs are multimedia and audio capabilities, various screen sizes (starting with a full screen), and modems (integrated or not, wireless, or wired). Which features are most important depends on the tasks that the user wishes to perform. In addition to these standard features, mobile telephones or clip-on cameras can be combined with several PDA models.

Primary PDA Manufacturers

Two of the leading manufacturers of PDAs are Palm, Inc. and Casio, Inc. PDAs made by Palm dominate the market with two popular models: the Palm m100 and the Palm VIIx. Both devices use the Palm OS 3.5 as an operating system, HotSync Manager 2.1.0, Pocket Mirror 2.0.7 as synchronizing software, and a 20-MHz Motorola DragonBall EZ as a processor. The Palm OS is fast, simple, and compatible with both Macintosh and Windows-based computers.

The amount of memory available in these devices is important, especially the amount of RAM. The Palm m100 has 2MB of RAM and 2MB of ROM. The Palm VIIx has more RAM (8MB) and the same amount of read only memory (ROM). Both use a touch screen as their input and have a speaker as well as an infrared port. To exchange data between Palm PDAs, users can beam information from one to another using an infrared port. Users also can place the Palm PDA into a docking cradle and synchronize their PDA with their microcomputers. The Palm VIIx has a docking serial cradle for synchronizing with a microcomputer and a built-in modem that can access the Internet or other networks without wires.

The PDA models produced by Casio offered the first 64-bit screens on the market. Casio's PDAs include the Casio Cassiopeia E-125 and the Cassiopeia EM-500. Both have color displays, use Windows CE 3.0 as an operating system and ActiveSync 3.1 as synchronizing software, and use a 150-MHz NEC VR4122 as a processor. Most of these use the Windows CE operating system (WinCE). WinCE is similar to Windows 95/98. It can run set-top TV controllers or small handheld devices that can communicate with each other and synchronize with Windows-based computers.

The Casio E-125 PDA has 32MB RAM while the EM-500 PDA has 16MB RAM. Both use touch screen or voice recorders as input and have a microphone and speaker as well as a stereo headphone jack and an infrared port.

Making PDAs More Useful

PDAs must be trained to recognize their users' handwriting. To do this, the user must write each numeric digit and letter (in uppercase) several times on the screen with the light pen. Even so, recognition is not always 100 percent. For users who really want a keyboard, text can also be entered by tapping the light pen on the appropriate letters from an on-screen virtual keyboard. There are other problems with entering data on the screen with just a light pen. How can users delete an entire word, or bring up an entire document? These problems have been solved in several ingenious ways. For example, deletion of a word occurs by crossing it out on the screen. Tapping the light pen on the name of a stored document brings it up on the screen.

As these problems are being solved, new applications for PDAs are being developed and new technologies are being combined with PDAs. For example, Symbol Technologies, Inc. has combined PDAs with bar code scanning equipment. Symbol is supplying the Kmart Corporation with in-store wireless and mobile computing solutions in its entire chain of more than 2,100 stores. Kmart is using Symbol's wireless local area network (LAN) and the company's PDT 6840 wireless devices for receiving merchandise, tracking inventory, and printing labels, and on the sales floor for price checking and employee communications. Many market watchers believe that PDAs will gain wide use in a variety of business applications, especially retailing, warehousing, and inventory control.

see also Microcomputers; Telecommunications; Wireless Technology; World Wide Web.

Terri L. Lenox and Charles R. Woratschek


Brown, Bruce, and Marge Brown. "Expanding Possibilities." PC Magazine, March 6, 2001, pp. 188200.

Turban, Efraim, R. Kelly Rainer, Jr., and Richard E. Potter. Introduction to Information Technology. New York: John Wiley and Sons, Inc., 2001.

Internet Resources

Casio Corporation Web Site. <>

Products, Services & Company Information. Palm, Inc. <>

Symbol Technologies Web Site. <>

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Personal Digital Assistant (PDA)


Personal Digital Assistants (PDAs) are handheld or pocket computers capable of a wide range of functions. At their most basic level, they serve as electronic address books and to-do lists. However, the capabilities of PDAs have evolved considerably since their introduction in the late 1980s to include wireless access to phone, fax, e-mail, the Internet and other subscription-based data services. Users are able to download information (including books, games, spreadsheets, and word processing documents) from desktop computers or the Internet to their PDAs and beam text messages or business information to other PDA users. Information can also be entered directly into PDAs by using a pen-like stylusmost PDAs are able to convert handwritten characters into typeor via small, portable keyboards.

Because immediate access to information is important to both consumers and retailers, PDAs' wireless properties make them especially valuable tools in the world of e-commerce. PDAs link to the Internet by using a communication standard known as wireless application protocol (WAP), in which a special computer language allows information to be displayed on small screens via a cellular connection. According to Nua Internet Surveys, The Strategis Group predicted the number of individuals subscribing to mobile data services would climb from 5 million in 2000 to 172 million in 2007. Also according to Nua Internet Surveys, Cahners In-Stat Group predicted wireless Internet access device sales would achieve triple-digit growth from 2000 to 2004, eventually surpassing desk-top computers as the most popular means of accessing the Internet.

According to The Detroit News, documents filed with the Securities and Exchange Commission by PDA manufacturer Handspring Inc. indicated sales of handheld computers would exceed $35 million by 2003. According to Federal Computer Week, IDC projected demand for PDAs to grow at a compound annual rate of 28.8 percent between 2000 and 2005.

In the early 2000s, it became possible for consumers with credit cards to purchase goods through wireless devices.,, and Barnes & were among the first retailers to begin offering shopping services to consumers in this manner. Wireless shopping portals also began to emerge, through which consumers could access products from a number of different retailers by downloading a single site onto their PDA or wireless phone.

According to InformationWeek, in the early 2000s Andersen Consulting developed prototype technology enabling PDAs and other wireless devices to function like synthetic currency. Known as Mobile Micropayments, the technology enables consumers to receive special offers from merchants in their immediate location via their wireless device. For example, a consumer who walks past a vending machine might be presented with a range of selections on the display of his or her PDA, which could be purchased immediately. Mobile Micropayments used Qpass Inc. to handle billing and payment in a manner very similar to automatic payment systems used on toll roads. The technology can be used to pay for everything from fast food to cab fares. In late 2000, Andersen Consulting expected an increasing number of devicesincluding printers, cash registers and vending machineswould be able to seamlessly communicate with other wireless devices in their immediate vicinity.

PDAs also are important to the corporate e-commerce sector. For example, salespeople are able to use them to access company databases for sales figures or inventory information, to conduct research, and to process orders. In Pharmaceutical Executive, Josh Weinstein, president of Torre Lazur PR Health-care Public Relations, explained: "Executives' connections to their workplaces are driven more and more by the Internet and wireless applications. Web-linked corporate e-mail seems to be the most developed, and it is common for traveling pharmaceutical executives to log on daily. More workgroup projects develop from such e-mail sessions than from the urgent voicemail messages or pages executives receive when office fires need to be extinguished."

PDAs also are valuable to securities brokers, who are able to use them in the trading process. In a Planet IT article by Talila Baron, Ron Valeggia, senior vice president and CIO of New York-based Quick & Reilly Inc., commented that the use of PDAs would increase tremendously due to their small size and convenience. Quick & Reilly's brokers already were using wireless phones to trade in mid-2000.

In 1989, Atari introduced the Atari Portfolio, one of the very first handheld computers. Apple Computer also became an early PDA pioneer when it introduced the Apple Newton in 1993. In 1996 U.S. Robotics, which eventually was acquired by 3Com, introduced its PalmPilot model, which eventually became a strong market leader. The introduction was a catalyst for the widespread adoption of PDAs by consumers. In the early 2000s, manufacturers of PDAs included Palm Inc., Handspring, Microsoft, Compaq, Symbian, Motorola, Hewlett-Packard, Fujitsu, Norand, Sharp, Psion, and Sony.


Jerome, Marty. "How WAP Works." ZDNet, February 6, 2001. Available from

Morrison, Kara G. "Handheld Computers are, well, Handy." The Detroit News, April 29, 2000. Available from

Nelson, Matthew G. "Innovation: A Remote Control for E-commerce." InformationWeek, October 30, 2000.

"Strategis Group: Mobile Data to Take Off in the U.S." NUA Internet Surveys, January 30, 2001. Available from

Zbar, Jeffery D. "E-commerce Eyes Potential of Communication Devices." Advertising Age, March 6, 2000.

SEE ALSO: Motorola, Inc.; Nokia Corp.; Palm, Inc.

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personal digital assistant

personal digital assistant (PDA), lightweight, hand-held computer designed for use as a personal organizer with communications capabilities; also called a handheld. A typical PDA has no keyboard, relying instead on special hardware and pen-based computer software to enable the recognition of handwritten input, which is entered on the surface of a liquid crystal display screen. In addition to including such applications as a word processor, spreadsheet, calendar, and address book, PDAs are used as notepads, appointment schedulers, and wireless communicators for sending and receiving data, faxes, and electronic-mail messages. Introduced in 1993, PDAs achieved only modest acceptance during the remainder of the decade due to their relatively high price and limited applications, but improved software and lower prices subsequently led to more widespread use. In the early 21st cent., however, smartphones (see cellular telephone) equipped with a wide range of applications supplanted PDAs. See also palmtop.

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"personal digital assistant." The Columbia Encyclopedia, 6th ed.. . 10 Dec. 2017 <>.

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personal digital assistant

personal digital assistant (PDA) A pocketbook-sized computer with a combined touch-sensitive membrane covering an LCD panel as its main input and output device. The user writes on the screen with a penlike stylus, and the objects drawn are echoed on the screen. It is possible to interpret handwriting by means of character-recognition techniques, to store what is written or drawn as images for later retrieval, or for the screen to display menus and check boxes so that selections may be made with the stylus. Applications include calendars, diaries, and personal organizer functions. Communications with other computers are also available.

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