Abstract: When display data are written into the terminal's display memory, the data indicative of the display coordinate are converted from the normalized values to the absolute values of the NTSC system or PAL system and are then written into the corresponding addresses of the display memory, so that regardless of the fact that the display is of the NTSC system or of the PAL system, the figure can be displayed with the correct aspect ratio. Further, when the coordinates are converted, the conversion is carried out such that the display resolution is regarded as the highest one, so that even if the resolution of the display is increased by increasing the capacity of the display memory, it is not necessary to change the conversion algorithm. For displays having less than full resolution capability, the display data is scaled by omitting some of the converted data when writing it into the display memory.

Abstract: A system for initializing a set of channel controllers in an information processing system reduces the time of initialization, the number of steps used in a microprogram, and necessary hardware. Address pointers of a plurality of control data areas relating to one of the channel controllers are utilized. Initialization data is sequentially read from a main memory of the information processing system. Address pointers of a channel controller are calculated by a predetermined procedure from the initialization data and a device number of the channel controller. The calculated address pointer is written into a local memory of the channel controller. Initialization is terminated upon reading an end of initilization data.