Personal digital assistants (PDAs) are one of the fastest selling consumer devices in history. That popularity means that there are many models to choose from. You should first ask yourself "What do I need my PDA for?" and "How much can I afford to spend on a PDA?" The answers to these questions will help you find the right model. Here is a list of features that should be considered:
- Size - hand-held vs. palm-sized
- Type of data entry - keyboard vs. stylus/touch-screen
- Operating system - PalmOS vs. PocketPC (formerly Windows CE)
- Power supply - disposable vs. rechargeable batteries, AC adapter
- cable - serial vs. USB port
- infrared (IR)
- telephone modem
- Special Features
- MP3 player
- MPEG player
- personal information management (PIM)
- spreadsheet, word processing, calculator
- voice recognition
- data synchronization
- Price - $150 to $1,000
Do you want a PDA that you can carry in your briefcase or in your pocket? PDAs come in hand-held or palm-sized models. The hand-held computers tend to be larger than the palm-sized. Most, but not all, palm-sized PDAs can fit into a shirt pocket. Also, PDAs vary in their weight from 4 to 8 ounces (113 to 227 grams).
Type of Data Entry
Which type of data entry do you prefer? Most hand-held PDAs use a miniature keyboard for data entry. Often the keyboards are too small for easy or comfortable typing. In contrast, palm-sized PDAs use a stylus/touch-screen technology in combination with hand-writing recognition software. This involves learning some shorthand alphabet, such as Palm's Graffiti, which can take some time to master fully.
This is one of the most important decisions to make! It is the PDA equivalent to "Should I buy an Apple Macintosh or IBM PC/PC clone?" The operating system used by PDAs are one of two types, Palm OS (3Com) or PocketPC (formerly called Windows CE, Microsoft). Palm OS takes up less memory, runs faster, and is easier to use. PocketPC easily supports color displays, graphics, standard Windows packages (Word, Excel), and other devices (e.g., built-in MP3 players, MPEG movie players); however, PocketPC takes up more memory, is slower, and more complicated to use. However, if it is important to be able to exchange files with Windows packages, then PocketPC might be a better choice. As of this writing, Palm OS dominates the market because its operating system is specifically tailored to the basic uses of a PDA. However, PocketPC is challenging Palm OS, and third-party software developers exist for both operating systems.
All PDAs have LCD displays. PDA displays have the following features:
- color vs. monochrome - Most PDAs are black-white (16 gray scales), but some have colors (65,536). PDAs with color screens need more memory and tend to be more expensive.
- pixel resolutions - PDAs have various pixel resolutions (160 x 160, 240 x 320). The higher the resolution, the clearer the display.
- passive or active matrix - active matrix displays have sharper images and are easier to read, but tend to be more expensive
- reflective or backlit - backlit screens are good for low level room lighting conditions
- size - Hand-held PDAs tend to have larger screens. Most palm-sized PDAs have four-inch (10 cm) square screens.
- writing area - Some PDAs only allow you to write in special areas of the screen, while others allow you to write anywhere
All PDAs use solid-state memory, usually