CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [364]
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NOTE Chapter 24, “Wireless Networking,” goes into more detail on all these technologies.
PDA Storage
Almost every PDA has both internal flash ROM memory of 1 MB or more and some sort of removable and upgradeable storage medium. Secure Digital (SD) technology has the strongest market share among the many competing standards, but you’ll find a bunch of different memory card types out there. SD is by far the most popular, with the cards coming in a variety of physical sizes (SD, Mini SD, and Micro SD) and fitting in a special SD slot. You’ll find capacities ranging from 4 MB up to 32 GB—on a card the size of a postage stamp! Figure 21-7 shows some typical memory cards.
Figure 21-7 SD and Micro SD cards
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NOTE Memory cards made the leap in 2003 from the exclusive realm of tiny devices such as PDAs and digital photographic cameras to full-featured portable PCs and even desktop models. Many laptop PCs sport SD card slots, for example, and you can expect nearly every Sony PC—portable or otherwise—made in 2003 and later to offer a Memory Stick port.
Tablet PCs
Tablet PCs combine the hand-writing benefits of PDAs with the full-fledged power of traditional portable PCs to create a machine that perfectly meets the needs of many professions. Unlike PDAs and smartphones, tablet PCs use a full-featured PC operating system such as Microsoft Vista Home Premium and up.
Instead of (or in addition to) a keyboard and mouse, tablet PCs provide a screen that doubles as an input device. With a special pen, called a stylus, you can actually write on the screen (see Figure 21-8). Just make sure you don’t grab your fancy Cross ballpoint pen accidentally and start writing on the screen! Unlike many PDA screens, most tablet PC screens are not pressure sensitive—you have to use the stylus to write on the screen. Tablet PCs come in two main form factors: convertibles, which include a keyboard that you can fold out of the way, and slates, which do away with the keyboard entirely. The convertible tablet PC in Figure 21-8, for example, looks and functions just like the typical clamshell laptop shown back in Figure 21-1. But here it’s shown with the screen rotated 180 degrees and snapped flat so it functions as a slate. Pretty slick!
Figure 21-8 A tablet PC
In applications that aren’t “tablet-aware,” the stylus acts just like a mouse, enabling you to select items, double-click, right-click, and so on. To input text with the stylus, you can either tap keys on a virtual keyboard (shown in Figure 21-9), write in the writing utility (shown in Figure 21-10), or use speech recognition software. With a little practice, most users find the computer’s accuracy in recognizing their handwriting to be sufficient for most text input, although speedy touch-typists will probably still want to use a keyboard when typing longer documents.
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NOTE Handwriting recognition and speech recognition are two technologies that benefit greatly from increased CPU power. As multicore CPUs become more common, get ready to see more widespread adoption of these technologies.
Tablet PCs work well when you have limited space or have to walk around and use a laptop. Anyone who has ever tried to type with one hand while walking around the factory floor and holding the laptop with the other hand will immediately appreciate the beauty of a tablet PC. In this scenario, tablet PCs are most effective when combined with applications designed to be used with a stylus instead of a keyboard. An inventory control program, for example, might present drop-down lists and radio buttons to the user, making a stylus the perfect input tool. With the right custom application, tablet PCs become indispensable tools.
Figure 21-9 The virtual keyboard
Figure 21-10