INT 15 - DESQview v2.23+ - "SCRNINFO" - GET TRUE VIDEO PARAMETERS
        AX = DE1Eh
Return: CL = actual number of rows on screen
        CH = actual number of columns on screen
        BL = actual video mode (may differ from INT 10/AH=0Fh return) (v2.26+)
Note:   this API call may be made from a hardware interrupt handler