Computer-based videos were introduced in multimedia PCs around 1991. They were a cool idea, but when the videos first appeared, they were really small. A 386/33 megahertz machine could support a video about 80x50 pixels with 15 frames per second (fps) and low-quality sound. Since then computer videos have improved significantly. They're now 320x200 pixels with 24 fps; conveying 24 times as much data per second as in 1991. These improvements in resolution and fps are still small compared to the ultimate video experience: a digital surround-sound movie. Real movies have about 4000x2000-pixel resolution, 24-bit color, and 4 channels of 44 kHz, 16-bit audio. That's several hundred times the data rate and processor speed of the videos you get on today's PCs.