2.5. Alternative Displays
The Web isn't just for personal computers anymore! Web browsers are increasingly making their way into our living rooms, briefcases, and cars, in the form of WebTV, handheld PDA devices, cellular phones, and dashboard devices. These extra-small displays introduce new design concerns.
WebTV, a device that turns an ordinary television and phone line into a web browser, hit the market in 1996 and is experiencing a slow but steady growth in market share. As of this writing, it is barely a blip on the radar screen of overall browser usage, but because numbers are increasing, some developers are taking its special requirements into consideration. Some sites are being developed specifically for WebTV.
WebTV uses a television rather than a monitor as a display device. The live space in the WebTV browser is a scant 544 378 pixels. The browser permits vertical paging down, but not horizontal scrolling, so wider graphics are partially obscured and inaccessible, or resized to fit. Principles for designing legible television graphics apply, such as the use of light text on dark backgrounds rather than vice versa and the avoidance of any elements less than 2 pixels in width. These and other guidelines are provided on WebTV's special developer site at http://developer.webtv.net.
Of particular interest is WebTV Viewer, which shows you how your web page will look on WebTV, right from the comfort of your computer. It is available for free for both Windows and Mac (although the Windows version is more up-to-date as of this writing). For information on WebTV Viewer, go to http://developer.msntv.com/Tools/WebTVVwr.asp.
2.5.2. Hand-held Devices
The increased popularity and usefulness of the Web combined with the growing reliance on hand-held communications devices (such as palm-top computers, PDAs, and cellular telephones) has resulted in web browsers squeezing into the coziest of spaces. Typically, wireless devices are used to view applications designed especially for them (see Chapter 32, "WAP and WML"), not the graphically-rich web sites that we are accustomed to on our computer browsers. Therefore, it is generally not necessary to worry about how your site will fare on a microbrowser.
The typical mobile phone with Internet capabilities has a display area that is between 95 and 120 pixels wide and 50 to 65 pixels high. Newer phones and PDAs may have larger screens (approximately 300 by 100 pixels). A more meaningful measurement than pixel size is the amount of text that can fit on the screen. In general, mobile browsers can display only three to six lines of text at a time with 12 to 20 characters per line.
The majority of mobile devices (particularly in North America) have only black and white LCD displays. However, in Japan, mobile devices with 8-bit color displays are growing in popularity.
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