Personal digital assistants (also called PDAs) are handheld devices that were
originally designed as personal organizers, but became much more versatile over
the years. A basic PDA usually includes date book, address book, task list, memo
pad, clock, and calculator software. Newer PDAs also have both color screens and
audio capabilities, enabling them to be used as mobile phones, web browsers or
media players. Many PDAs can access the Internet, intranets or extranets via
Wi-Fi, or Wireless Wide-Area Networks (WWANs).
Many original PDAs, such as the Palm Pilot, featured touch screens for user
interaction, having only a few buttons usually reserved for shortcuts to often
used programs. Touch screen PDAs, including Windows Pocket PC 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.
Text input is usually done in one of two ways:
* Using a virtual keyboard, where a keyboard is shown on the touch screen.
Input is done by tapping the letters.
* 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
PDA's for business use, including the BlackBerry and Treo, have a full keyboard
and scroll wheel or thumb wheel to facilitate data entry and navigation.
An important functionality for PDAs is the possibility of synchronizing data
with a contact database, such as Microsoft Outlook or ACT!, hosted on a personal
computers or corporate server. The data synchronized ensures that the PDA has an
accurate list of contacts, appointments and e-mail, allowing users to access the
same information on the PDA as the host computer.
The synchronizing also prevents the loss of information stored on the device in
case it is lost, stolen, or destroyed. Another advantage is that data input is
usually a lot quicker on a personal computer, since text input via a touch
screen is still not quite optimal. Transferring data to a PDA via the computer
is therefore a lot quicker than having to manually input all data on the
Most PDAs come with the ability to synchronize to a personal computer. This is
done through synchronization software provided with the handheld, such as
HotSync Manager, which comes with Palm OS handhelds, or Microsoft ActiveSync,
which comes with Windows Mobile handhelds.
These programs allow the PDA to be synchronized with a personal information
manager. This personal information manager may be an outside program or a
proprietary program. For example, the BlackBerry PDA comes with the 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 Palms such as the Treo 650 has
the built-in ability to sync to Palm Desktop and/or Microsoft Outlook.
Third-party synchronization software is also available for many PDAs from
companies like Intellisync and CompanionLink. This software synchronizes these
handhelds to other personal information managers which are not supported by the
PDA manufacturers, such as GoldMine and Lotus Notes.
Like a personal computer, it is possible to install additional software on
most PDAs. Software can be bought or downloaded from the Internet, allowing
users to personalize their PDAs to their liking. Some PDAs also allow for adding
hardware. The most common is a memory card slot, which allows the users to get
additional and exchangeable storage space on their handheld devices. There are
also miniature keyboards that can be connected to some PDAs for quicker text
input. PDAs with Bluetooth can also use Bluetooth devices like headsets and
foldable keyboards with their PDAs.
Other functions are commonly added to PDAs. Some examples are:
* Audio recording
* Camera functionality, allowing users to take photos or short video clips
* Map functionality, with a GPS receiver for localization
* Cell Phone functionality, which lets users make and receive phone calls, SMS
and MMS messages.
* Media Player abilities
For many years businesses and government organizations have relied upon
rugged PDAs for mobile data applications. Typical applications include supply
chain management in warehouses, package delivery, route accounting, medical
treatment and record keeping in hospitals, facilities maintenance and
management, parking enforcement, access control and security, capital asset
maintenance, meter reading by utilities, and "wireless waitress" applications in
restaurants and hospitality venues.
The term "personal digital assistant" was coined on January 7, 1992 by then
Apple Computer CEO John Sculley at the Consumer Electronics Show in Las Vegas,
Nevada, referring to the Apple Newton. Earlier devices like the Psion and Sharp
Wizard already had the functionality to be considered PDAs, however. In fact,
PDAs by other names were available as early as the mid-1970s -- first as very
advanced calculators, then as electronic organizers, and later as palmtops. .
PDAs are some times referred to as "Palms" or "Palm Pilot" after an early PDA
created by Palm, Inc. This usage is a case of genericized trademark, similar to
referring to a tissue as a "Kleenex", a bandage as a "Band-Aid", or a pen as a
The currently major PDA operating systems are:
* Palm OS - owned by Palm, Inc.
* Windows Mobile (Pocket PC), (based on the Windows CE kernel) - owned by
* RIM for the BlackBerry - owned by Research In Motion
* Many operating systems based on the Linux kernel - free (not owned by any
company) These include:
o GPE - Based on GTK+/X11
o OPIE/Qtopia - based on Qt/E Qtopia is developed by Trolltech, OPIE is a fork
of Qtopia developed by volunteers
* Symbian OS (formerly EPOC) owned by Ericsson, Panasonic, Nokia, Samsung,
Siemens and Sony Ericsson
Many PDAs run using a variation of the ARM architecture (usually denoted by
the Intel XScale trademark). This encompasses a class of RISC microprocessors
that are widely used in mobile devices and embedded systems, and its design was
influenced strongly by a popular 1970s/1980s CPU, the MOS Technology 6502.
According to a Gartner market study, the overall market for PDAs grew by
20.7% in the third quarter (Q3) of 2005, compared to Q3 2004, with marketshare
resolving as follows (by operating system):
* Palm OS for Palm, Inc. PDAs and some other licensees- 14.9% (declining)
* Windows Mobile for PDAs that comply with the Microsoft's Pocket PC
specifications - 49.2% (increasing)
* RIM BlackBerry for BlackBerry PDA (produced by Research In Motion) - 25.0%
* Symbian OS - 5.8% (increasing)
* Various operating systems based on the Linux kernel for various special
designed PDAs (many other supported) - 0.7% (stable)
* Other - 4.4% (stable)
The reason usually cited for the resumption in PDA market growth (after market
declines in 2002 - 2004) is the growing interest in PDAs as Personal
Communicators offering wireless email capabilities (such as BlackBerries), and
PDAs with built-in GPS capabilities for navigation. It is possible that
Smartphones, mobile phones with PDA-like abilities, will curtail growth in the
sales of PDAs without telephony capabilty in the near future, as they subsume
more of the same functions.
Popular Consumer PDAs
* Palm IIIxe PDA
* Palm IIIxe PDA
* Apple Newton
* hp iPAQ Pocket PC (Originally Compaq iPAQ until HP merged in 2002)
* Palm Pilot, Tungsten, LifeDrive, Treo and Zire
* Sharp Wizard and Zaurus
* Sony CLIΙ
* High Tech Computer Corporation's series of Windows Mobile PDA/phones
* Tapwave Zodiac
* AlphaSmart Dana
* Dell Axim
* GMate Yopy
* Fujitsu Siemens Loox
* List of Palm OS Devices
* Abacus PDA Watch
* PocketMail (email PDA with inbuilt acoustic coupler)
Note: This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Personal digital assistant".