American Megatrends Super Voyager LPX User Manual page 136

Super VGA Functions,
Function 05h Subfunction 01h Return SVGA Video Memory
Window
Input: AH = 4Fh SVGA support
AL = 05h SVGA video memory window control
BH = 01h Return SVGA video memory window
BL = Window number
0 Window A
1 Window B
Output: AX = Status
DX = Window position in video memory (in window
granularity units)
This function is also directly accessible through a far call from the
application. The address of the BIOS function may be obtained via INT
10h Function 01h Return SVGA Mode Information. A field in the
ModeInfoBlock contains the address of this function. This function may
be different among video modes in a BIOS implementation so the
function pointer should be obtained after each set mode.
In the far call version, no status information is returned to the
application. Also, in the far call version, the contents of AX and DX
registers are destroyed. If AX and DX must be preserved, the application
must do so before making the far call.
The application must load the input arguments in BH, BL, and DX for
set window but does not need to load either AH or AL to use the far call
version of this function.
Chapter 4 VGA BIOS
130
Continued