Abstract: Video data for two or more video streams are processed by a single background command list containing one or more background commands and a single foreground command list containing one or more foreground commands, where the foreground command list is implemented only during a vertical blanking interval of the display raster of a monitor. The processed video data are then displayed during the raster period. In a preferred embodiment, if the implementation of a background command has not completed by the start of a vertical blanking interval, the background command is interrupted, the state of the background command implementation is saved, the foreground command list is implemented, and then the interrupted background command is resumed. The background commands are preferably those that do not directly affect the display bitmaps, while the foreground commands are those that do directly affect the display bitmaps.

Abstract: First and second application programs run on a host processor. The driver loads, runs, and unloads a first microcode program of the first application program onto an Intel.RTM. i750.RTM. Pixel Processor. The driver then loads, runs, and unloads a second microcode program of the second application program onto the Intel.RTM. i750.RTM. Pixel Processor. The driver repeats these steps such that the first and second application programs run concurrently.