Function 15, subfunction 4 - set drawing mode for the background.
Parameters:
- eax = 15 - function number
- ebx = 4 - subfunction number
- ecx = drawing mode:
Returned value:
- function does not return value
Remarks:
- For update of the screen (after completion of a series of commands
working with a background) call subfunction 3.
- There is a pair function for get drawing mode of the background -
subfunction 4 of function 39.