News Channel Five has been advising viewers for a while now to mark a very important date on the calendar: Feb. 17, 2009. That date points to digital broadcast transition day, which is when analog television signals stop and digital programming begins. The change from analog to digital is comprehensive with no provisions for backward compatibility. That means old analog televisions receiving signals by antenna will not work after that date. We will have two basic choices while preparing for the date. We can keep the old set and use a converter box or buy a digital ready TV. Using a converter box is pretty straightforward; buying a new digital TV is anything but. The numbers alone are very confusing so lets spend a little time on what some of them mean. Televisions for a long time were mostly Cathode Ray Tube now an old technology. Today we have new TV technologies like Liquid Crystal Display and plasma. Of those two, plasma ruled the large-screen market and LCD ruled the small-screen market. Recent advances in LCD technology has made large screen LCD TVs possible and popular. In fact, LCD units are now lighter and more durable than comparable plasma units and LCD offers the same high-quality picture usually at a cheaper price. The viewing area of a TV is the area where the picture is displayed. Early televisions had a 4:3 viewing area; new TVs are coming with 16:9 viewing areas. Both numbers are just ratios of width to height. For every 4 units of width there are 3 units of height for 4:3 and the same is true for 16:9 televisions, which are called widescreen TVs. Next week well look resolution factors and examine what some of the other numbers like 720p and 1080i mean. Ron Poland is a professor in the Computer Information Systems AAS program at Clinton Community College. Poland is certified in company repair and networking by the Computer Technology Industry Association (CompTIA). He is also a Cisco certified network assistant.