Function 15, subfunction 1 - set a size of the background image.
Parameters:
- eax = 15 - function number
- ebx = 1 - subfunction number
- ecx = width of the image
- edx = height of the image
Returned value:
- function does not return value
Remarks:
- There is no checks for correctness. The setting of too large
values will result that the background will contain data abroad
of buffer for the background image. Buffer size = 0x160000-0x10,
that corresponds to maximum size 800*600. (800*600*3=0x15F900)
- 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 size of the background image -
subfunction 1 of function 39.