Personal digital assistants (PDAs) are handheld devices that are small computers that can be used for administrative, communication and collaboration, teaching and learning applications. They are also referred to as, a Palm, or Pocket PCs. PDAs can be used for: calculating, as a clock and calendar, playing computer games, accessing the Internet, sending and receiving e-mail, used as a radio or stereo, used for video recording, recording notes, as an address book, GPS and also enabled for spreadsheet applications. Newer PDAs have both color screens and audio capabilities, allowing them to be used as mobile phones (smartphone), web browsers or portable media players. Many PDAs can access the Internet, intranets or extranets via Wi-Fi, or Wireless Wide-Area Networks (WWANs). One of the most significant PDA characteristic is the presence of a touch screen.
Printers are devices that print documents stored in electronic form as text or illustrations on paper or transparencies. In terms of the technology utilized, printers fall into the following categories:
Dot-matrix: Create characters by striking pins against an inked ribbon. Each pin makes a dot, and combinations of dots form characters and illustrations..
Ink jet and bubble jet: Work by spraying ink at a sheet of paper, producing high-quality text and graphics.
Laser: Uses the same technology as Xerox machines and produce very high quality text and graphics.
LCD & LED : Similar to a laser printers, but use liquid crystals or light-emitting diodes rather than a laser to produce images.
Line printer: Contain a chain of characters or pins that print an entire line at one time. Line printers are very fast, up to 3,000 lines per minute, but produce low-quality print.
Thermal printer: Work by pushing heated pins against heat-sensitive paper.
Direct interface: In addition, many modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras and scanners.
Printers often get left behind when WiFi comes in -- the cables needed to link them to a PC may then wind up anchoring at least one computer to a desk. Printing from any other machine involves printer sharing, or transferring individual files to the one machine wired to the printer. Putting the printer on the wireless network is an obvious remedy, allowing placement of the WiFi-enabled printer anywhere, and easily share it with every computer on the network
Until recently, built-in WiFi was a bit of a novelty in printers, confined to pricier devices intended for use in office networks. That's now starting to change with lower prices targeting home and SOHO applications.
By Rick Zarr, National Semiconductor Corp. With any technology, consumers drive the next generation. After all, technology is defined by how people use it. In the case of video, we have gone from the early days of extremely heavy and expensive black and white, tube based “television” devices circa 1950s to today’s modern flat panel LCD and Plasma Television / Monitors. With...
