A personal digital assistant, also known as a palmtop computer, or personal data assistant,
is a mobile device that functions as a personal information manager.
PDAs are largely considered obsolete with the widespread adoption of smartphones.
Nearly all current PDAs have the ability to connect to the Internet.
A PDA has an electronic visual display, enabling it to include a web browser, all current 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, the Organizer.
Followed by Psion's Series 3, in 1991, which began to resemble the more familiar PDA style.
It also had a full keyboard.
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 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 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 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 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.
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 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 slot or a CompactFlash slot.
Although designed for memory, Secure Digital Input/Output 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, 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.
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 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, 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.
Synchronization 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
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 and CompanionLink.
Third-party software can be used to synchronize PDAs to other personal information managers
that are not supported by the PDA manufacturers.
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 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.
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.
Email, calendar entries, contacts, tasks, and memos kept on the company's server are
automatically synchronized with the BlackBerry.
Operating systems of PDAs The most common operating systems preinstalled
on PDAs are: Palm OS
Microsoft Windows Mobile with a Windows CE kernel.
Android iOS
WebOS Other, rarely used operating systems:
EPOC, then Symbian OS Linux
Newton QNX
Automobile navigation Some PDAs include Global Positioning System
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.
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, for mobile
data applications.
EDAs often have extra features for data capture, such as barcode readers, radio-frequency identification
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 AvantGo translate medical journals into PDA-readable formats.
WardWatch organizes medical records, providing reminders of information such as the treatment
regimens of patients to doctors making 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.
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 Popular consumer PDAs
Discontinued PDAs
Rugged PDAs
See also
References
External links Annotated bibliography of references to gesture
and pen computing