Video Cards For Personal Computers

60 February 1989 VIDEO CARDS FOR PERSONAL COMPUTERS by H. Stenhouse In recent years a bewildering variety of video cards for PCs has come on to the market. This article attempts to remove much of the confusion caused by the different specifications and monitor requirements. Functionally, the video card in a per- sonal computer is an output device. Over the past few years, as PCs grew more sophisticated and users more deman- ding, the video card has become more than the fairly simple text display circuit of yesteryear. At that time, no provision was made for displaying, say, a graph on the screen. Fortunately, this was cor- rected with the introduction of the Colour Graphics Adaptor (CGA), which did allow, at least partly, for integration of text with simple graphics. The main disadvantage of the CGA was, however, its limited resolution for text. The well- known Hercules card, developed by the company of the same name, overcame this shortcoming at least for monochrome text applicat...