Process for scrolling a plurality of raster lines in a window of a personal computer display screen run in graphic mode

摘要

The invention relates to a procedure for scrolling some raster scan lines in a window of a screen operated in the graphic-mode of a personal computer. The computer has a processor and a program memory allocated to it as well as a video card connected to the processor via an external bus. The video card has a video memory (RAM), whose memory contents can be presented on the screen. One first line of the raster scan lines to be scrolled, is moved into a raster scan line within the window and is marked with a source-pointer. The raster scan line within a window, in which this line is to be moved into, is marked with a destination pointer. Afterwards, a scroll is performed and repeated until all lines to be scrolled are in raster scan lines of the window. At the same time with the first line, the subsequent third line is also at least scrolled in raster scan lines of the screen window. Afterwards, the second line and the fourth line of some raster scan lines to be scrolled are scrolled from lines in raster scan lines of the screen window and so on until all lines to be scrolled are scrolled in raster scan lines of the window.