Graphic display control apparatus

Claim 1

A graphic display control apparatus for sequentially scrolling display contents of a screen by sequentially shifting read-out areas to read display information of one screen from a frame memory whose capacity allows a CPU to write larger display information than one screen therein and transferring display information at each read-out area to a display unit, the graphic control apparatus comprising: an address storing means for storing a reading address specifying the read-out area at the starting time of scroll; a scroll-amount storing means for storing the amount of one scroll; a scroll-times storing means for storing the number of scrolls to be executed; an operation means for updating the reading address stored in said address storing means by a value corresponding to the amount of one scroll; an address generating means for generating an address of the frame memory from which display information is to be read out according to the reading address stored in said address storing means; and a counting means for counting the number of executed scrolls, wherein the display contents of the screen are scrolled horizontally, vertically or diagonally in accordance with the amount of scrolling.