OTHER TECH

Q. So how much HDTV will I be able to see?A. Hundreds of hours of high-def programming are now available every month from the major networks. That includes almost every prime-time drama and sitcom on ABC, CBS, and NBC along with some sports and special events, such as the Super Bowl and the Olympics. You'll also find some HDTV programming on the UPN, WB, and PBS networks. Even Fox, which has been doing 480p (progressive-scan) digital broadcasts, plans to switch over to high-def by fall of 2004.

Q. The ads for HDTVs are full of numbers like 720p, 1080i, and 16:9, but do they really matter?A. "Regular TVs," or analog TVs, are designed to display only one type of signal, 480-line interlaced NTSC programs, or what's now called the 480i (interlaced) format. Digital TV, on the other hand, can be broadcast in several signal formats at various pixel resolutions and in two screen shapes, or aspect ratios. But any HDTV with a built-in digital tuner can receive and display all of them. Keep in mind, though, that "receiving" and "displaying" are different concepts. While all HDTV tuners can receive every digital transmission, many convert some formats to fit the display capabilities of the monitor they're built into or connected to.

An HDTV picture has a widescreen 16:9 aspect ratio - as opposed to the squarish 4:3 ratio of traditional TV - and is made up either of 1,080 scanning lines transmitted in an interlaced format (1080i) or 720 scanning lines transmitted progressively (720p). To create an interlaced picture, the odd and even lines that make up a video frame are assigned to two different fields that are then displayed sequentially. In a progressive-scan picture, each line of the frame is scanned sequentially, so that the entire frame is displayed together. Progressive-scan formats tend to do better with programs that have a lot of fast-moving action, such as sporting events, and provide full vertical resolution at all times.

Furthermore, some digital TVs are "enhanced-definition" rather than true high-definition displays, which means they can display 480 scan lines progressively (480p). That number might sound familiar since progressive-scan DVD players produce 480p images.

Q. My cable/satellite company says it's transmitting digitally. Does that mean I can already get HDTV?A. It depends. Cable and satellite companies use digital technology primarily to squeeze more standard-definition channels into their available spectrum. But the EchoStar and DirecTV satellite services offer some HDTV channels. To stay competitive, a number of cable channels are offering high-def versions of their programming, including HBO, Showtime, the Discovery Channel, ESPN, and Starz. Don't be misled, though, by how your service describes what it offers. "Digital cable," for instance, doesn't necessarily mean HDTV.

Q. Do the cable and satellite companies carry HDTV programming from the major networks the same as they do the networks' regular programming?A. Some cable and satellite companies have balked at transmitting the HDTV versions of the networks' channels, arguing that they would have to use valuable channel capacity to offer different versions of the same programming for those with HDTVs and for those with regular TVs. Though EchoStar offers CBS's HDTV shows via the network's New York or Los Angeles digital stations, for the most part the satellite services are not carrying HDTV programming from the commercial networks. You can still tune in such programming via local over-the-air digital broadcasts or from an increasing number of cable systems.

Q. Can I just plug the cable into my new high-definition TV to see HDTV?A. In most cases, no. Only a handful of sets recently introduced by Panasonic and Hitachi offer this, and your cable company would still need to supply a CableCARD - a credit-card-size module that plugs into a slot on the TV and lets you view scrambled channels you've subscribed to. But CableCARDs should become available over the next few months, and the number of cable-ready sets is likely to increase quickly now that the consumer-electronics and cable industries have agreed on plug-and-play standards that let HDTVs receive digital cable and high-def programming without an external converter box. If you don't have one of these new sets, though, you'll need to get an HDTV-capable set-top box from your cable provider to watch both high-def and standard-def digital channels.