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Personal digital assistants (PDA or palmtop) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. A basic PDA usually includes a clock, date book, address book, task list, memo pad, and a simple calculator. One major advantage of using PDAs is their ability to synchronize data with home computers.
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The term "personal digital assistant" was coined on January 7, 1992 by John Sculley at the Consumer Electronics Show in Las Vegas, Nevada, referring to the Apple Newton. Earlier devices like the Psion and Sharp Wizard have the functionality to be considered PDAs, however.
The currently major PDA operating systems are:
- Palm OS - owned by PalmSource, Inc.
- Windows Mobile (Pocket PC), (based on the Windows CE kernel) - owned by Microsoft
- BlackBerry - owned by Research In Motion
Many operating systems based on the Linux kernel - free (not owned by any company) These include:
- GPE - Based on gtk/X11
- 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. In its classic instant-on, silent operation, restricted storage and space, and single-tasking UI approach, the PDA can be seen as a logical descendent of the low power consumption, compact, limited capacity home computer popular during the late 1970s and 1990s. This class of machines has been largely replaced by descendents of the IBM PC that generally feature long boot-up times, fast execution CPUs that require active, noisy cooling, and very large capacity hard drives that produce additional noise and heat.
According to a Gartner market study, the overall market for PDAs shrank by 5% in the first quarter (Q1) of 2004, compared to Q1 2003, with marketshare resolving as follows (by operating system):
- Palm OS for palmOne PDAs and some other - 40.5% (stable)
- Windows Mobile for PDAs that comply with the Microsoft's Pocket PC specifications - 40.4% (slightly increasing)
- BlackBerry OS for BlackBerry PDA (produced by Research In Motion) - 14.8% (strongly increasing)
- Various operating systems based on the Linux kernel for various special designed PDAs (many other supported) - 1.9% (stable)
- Other - 2.4% (strongly decreasing)
The reason usually cited for this decline is the growing capabilities of smartphones — mobile phones with PDA-like communication abilities.
Popular PDAs
- palmOne Tungsten T5BlackBerry
- hp iPAQ Pocket PC (Originally Compaq iPAQ until HP merged in 2002)
- Palm Pilot, Tungsten, Life Drive Mobile Manager, Treo and Zire
- Sharp Wizard and Zaurus
- Sony CLIÉ
- Tapwave Zodiac
- AlphaSmart Dana
- Dell's Axim
- GMate's Yopy
- Fujitsu Siemens Loox 720
- Apple's Apple Newton
Source Wikipedia
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