A personal digital assistant ( PDA ), also known as handheld PC , is a range of mobile devices that work as a personal information manager. PDAs were largely discontinued in early 2010 after the adoption of highly capable smartphones, especially those based on iOS and Android.
Almost all PDAs have the ability to connect to the Internet. The PDA has an electronic visual display, letting it include a web browser. Most models also have audio capabilities, allow use as portable media players, and also allow most of them to be used as a phone. Most PDAs can access the Internet, intranet or extranet via Wi-Fi or Wireless Wide Area Network. Sometimes, not a button, the PDA will use touch screen technology. The technology industry has recently recycled the term personal digital help. This term is more commonly used for software that identifies a user's voice to reply to a question.
The first PDA, the Organizer, was released in 1984 by Psion, followed by Psion's Series 3, in 1991. The latter began to resemble a more familiar PDA style, including 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 Apple Newton. In 1994, IBM introduced the first PDA with full phone functionality, IBM Simon, which can also be considered as the first smartphone. Then in 1996, Nokia introduced the PDA with the phone function, 9000 Communicator, which became the world's best-selling PDA. Another early participant in this market was Palm, with a PDA product line starting in March 1996.
These pocket-sized devices are sometimes called personal data assistants.
Video Personal digital assistant
Typical features
Typical PDAs have touch screen for navigation, memory card slot for data storage, and IrDA, Bluetooth and/or Wi-Fi. However, some PDAs may not have a touch screen, using softkey buttons, direction pad, and numeric keypad or thumb keyboard for input. To have the expected functionality of a PDA, device software usually includes appointment calendars, to-do lists, address books for contacts, calculators, and some sort of memo (or "note") program. PDAs with wireless data connections also typically include email clients and Web browsers, and may or may not include phone functions.
Touch screen
Many original PDAs, such as Apple Newton and Palm Pilot, feature touch screens for user interaction, with just a few buttons - usually reserved for shortcuts to frequently used programs. Some touch screen PDAs, including Windows Mobile devices, have a removable stylus to facilitate the selection. Users interact with the device by tapping the screen to select a button or issue a command, or by dragging a finger (or stylus) on the screen to make a selection or scroll.
Typical methods of entering text on a touch screen PDA include:
- Virtual keyboard, where the keyboard is displayed on the touch screen. Text is entered by tapping the on-screen keyboard with your finger or stylus.
- The external keyboard is connected via USB, infrared port, or Bluetooth. Some users can choose a chord keyboard for one-handed use.
- Handwriting recognition, where letters or words are written on the touch screen, often with a stylus, and a PDA turns the input into text. Recognition and calculation of handwriting horizontal and vertical formulas, such as "1 2 =", may also feature.
- The introduction of a stroke allows the user to create a standard stroke set on the touch screen, sometimes in a special input area, representing the various characters to be inputted. Strokes are often simplified characters, making it easier for devices to recognize. One of the most widely known stroke recognition systems is Palm's Graffiti.
Despite research and development projects, end users experience mixed results with handwriting recognition systems. Some people feel frustrated and inaccurate, while others are satisfied with the quality of recognition.
Touch screen PDAs intended for business use, such as BlackBerry and Palm Treo, usually also offer full keyboard and scroll or thumb wheel to facilitate data entry and navigation. Many touch screen PDAs support some form of external keyboard as well. The special folding keyboard, which offers full-sized but collapsing keyboards into compact size for transportation, is available for many models. The external keyboard can be attached to a PDA directly, using a cable, or it can use wireless technology such as infrared or Bluetooth to connect to a PDA. Newer PDAs, such as HTC HD2, Apple iPhone, Apple iPod Touch and Palm Pre, Palm Pre Plus, Palm Pixi, Palm Pixi Plus, Google Android (operating system) include more forms of touch screens that can register multiple touches simultaneously. This "multi-touch" view allows the more sophisticated interface to use various movements that are inserted with one or more fingers.
Memory card
Although many early PDAs did not have a memory card slot, most now have some form of Secure Digital (SD) slot, CompactFlash slot or a combination of both. Although designed for memory, Secure Digital Input/Output (SDIO) and CompactFlash cards are available that provide accessories such as Wi-Fi or digital cameras, if the device can support it. Some PDAs also have USB ports, especially for USB flash drives. Some PDAs use microSD cards, which are electronically compatible with SD cards, but have a much smaller physical size.
Cable connectivity
While the initial PDA connects to a user's personal computer through a serial port or other proprietary connection, many of these days are connected via a USB cable. Older PDAs can not connect to each other via USB, because their USB implementations do not support acting as "host". Some early PDAs can connect to the Internet indirectly via an external modem connected via a PDA serial port or a "sync" connector, or directly by using an expansion card that provides an Ethernet port.
Wireless connectivity
Most modern PDAs have Bluetooth, a popular wireless protocol for mobile devices. Bluetooth can be used to connect the keyboard, headset, GPS receiver, and other accessories nearby. It is 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 mobile telecommunication companies. PDAs older than the 1990s to 2006 typically have IrDA ports (infrared) that allow short-range, line-of-sight wireless communications. Some models currently use this technology, because it has been replaced 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 operating system supports them. The universal PDA keyboard designed for older PDAs uses infrared technology. Infrared technology is low cost and has the advantage of being allowed up.
Sync
Most PDAs can sync their data with applications on a user's computer. This allows users to update contacts, schedules, or other information on their computers, using software such as Microsoft Outlook or ACT !, and have the same data transferred to the PDA - or transfer the latest information from the PDA back to the computer. This eliminates the need for users to update their data in two places. Sync also prevents the loss of information stored on the device if it is lost, stolen, or destroyed. When the PDA is repaired or replaced, the PDA can be "synced back" with the computer, recovering user data. Some users find that data inputs are faster on their computers than in their PDAs, as text input via a touch screen or small-scale keyboard is slower than a full-size keyboard. Transferring data to a PDA via a computer is therefore much faster than having to manually enter all the data on a handheld device.
Most PDAs come with the ability to sync to a computer. This is done through the sync software provided with a handheld device, or sometimes with a computer 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 (like iPhone and iPod touch)
- iSync, included with Mac OS X, can sync many PDAs that support SyncML
- BlackBerry Desktop Software, used to sync BlackBerry devices.
These programs allow the PDA to be synchronized with a personal information manager, which can be part of the computer's operating system, provided with a PDA, or sold separately by a third party. For example, RIM BlackBerry comes with RIM's Desktop Manager program, which can be synchronized to Microsoft Outlook and ACT !. Other PDAs only come with their own software. For example, some early Palm OS PDAs come with Palm Desktop only, while Palm PDAs like Treo 650 have the ability to sync to Palm Desktop or Microsoft Outlook. Microsoft ActiveSync and Windows Mobile Device Center only synchronize with Microsoft Outlook or Microsoft Exchange servers. Third-party sync tools are 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 PDA manufacturers do not support (eg GoldMine and IBM Lotus Notes). Wireless sync
Some PDAs can synchronize some or all of their data using their wireless networking capabilities, rather than having to connect directly to a personal computer via cable. Devices running webOS Palm or Google's Android operating system are mainly synced with the cloud. For example, if Gmail is used, the information in contacts, emails, and calendars can be synchronized between the PDA and Google servers. RIM sells BlackBerry Enterprise Server to companies so that corporate BlackBerry users can synchronize their PDAs wirelessly with Microsoft Exchange Server, IBM Lotus Domino, or Novell GroupWise servers. Email, calendar entries, contacts, tasks and memos stored on the company's servers are automatically synced with BlackBerry.
Maps Personal digital assistant
PDA operating system
The most common operating systems pre-installed on PDAs are:
- Palm OS
- Microsoft Windows Mobile (Pocket PC) with Windows CE kernel
Other, rarely used operating systems:
- EPOC, then Symbian OS (on PDA combo phone)
- Linux (eg VR3, iPAQ, Sharp Zaurus PDA, Opie, GPE, Linux Familiar, etc.)
- Newton
- QNX (also on iPAQ)
Some PDAs include a Global Positioning System (GPS) receiver; this is especially true for smartphones. Other PDAs are compatible with an external GPS receiver-receiver that uses a PDA processor and screen to display location information. PDAs with GPS functionality can be used for automotive navigation. PDAs are increasingly paired as standard on new cars. GPS-based PDAs can also display traffic conditions, perform dynamic routing, and point out the known locations of mobile radar guns on the roadside. TomTom, Garmin, and iGO offer GPS navigation software for PDAs.
Ruggedized
Some businesses and government organizations rely on rough PDAs, sometimes known as corporate digital assistants (EDA) or mobile computers, for mobile data applications. This PDA has features that make it more powerful and able to handle bad weather, shock and humidity. EDA often has additional features for data retrieval, such as barcode readers, radio frequency readers (RFID) readers, magnetic card readers, or smart card readers. These features are designed to facilitate the use of this device to scan product codes or goods codes.
Typical applications include:
- Military (US Army)
- Rangers
- Wildlife biologist
- Supply chain management in a warehouse
- Package delivery
- Route accounting
- Medical care and hospital records
- Facility maintenance and management
- Parking enforcement
- Access control and security
- Maintenance of capital assets
- Meter reading by utility
- Waiter apps and waitresses in restaurants and hotels
- Audit and monitoring of infection control in a health care setting
- Allocations and taxi routing
Medical and scientific uses
Many companies have developed PDA products intended for the medical profession, as PDAs are loaded with drug databases, medical information, and medical information. Services like AvantGo translate medical journals into PDA-readable formats. WardWatch organizes medical records, providing information reminders such as patient treatment regimens to doctors who make round wards. Pendragon and Syware provide tools to do research with, allowing users to enter data into a centralized database using their PDA. Microsoft Visual Studio and Sun Java also provide programming tools to develop survey instruments on handheld devices. This development tool allows integration with SQL databases stored on handheld devices and can be synchronized with desktop or server-based databases. PDAs have been used by physicians to assist with the diagnosis and selection of drugs and some studies have concluded that when patients can use PDAs to record their symptoms they communicate more effectively with hospital staff during follow-up visits. The development of Web Sensor technology can lead to body sensors that can be used to monitor ongoing conditions, such as diabetes or epilepsy, which will alert patients and doctors when treatment is required using wireless communication and PDA.
Education usage
PDAs and handheld devices are allowed in many classrooms for digital recording. Students can spell-check, modify, and alter their class notes in the PDA. Some educators distribute the course material via the internet or the file-sharing function of the infrared PDA. Textbook publishers have begun releasing e-books, which can be uploaded directly to PDAs, reducing the number of textbooks that students must carry. Brighton and SUSSEX Medical School in the UK is the first medical school to provide large-scale PDA to undergraduate students. The learning opportunities provided by having a complete PDA with a set of key medical texts were studied with results indicating that learning takes place in context with timely access to key facts and through the consolidation of knowledge through repetition. PDA is an important addition to the learning ecology rather than a replacement. Software companies have developed PDA programs to meet the instructional needs of educational institutions, such as dictionaries, thesauri, word processing software, encyclopedias, webinars and digital lesson planners.
Use recreation
PDAs can be used by music fans to play various music file formats. Many PDAs include MP3 player function. Road rally fans can use a PDA to calculate distance, speed, and time. This information can be used for navigation, or the GPS function of PDA can be used for navigation. Underwater divers can use PDAs to plan respiratory gas mixtures and decompression schedules using software such as "V-Planner".
Model
Consumer
Ruggedized
See also
References
External links
- Bibliography annotated references to gestures and computational pens
- epocalc list from PDA manufacturer
Source of the article : Wikipedia
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