INT 15 - TopView - "POSWIN" - POSITION WINDOW
        AX = 1023h
        BX = segment of object handle for parent window within which to
             position the window (0 = full screen)
        ES = segment of object handle for window to be positioned
        DL = bit flags
             bits 0,1: horizontal position
                00 = current
                01 = center
                10 = left
                11 = right
             bits 2,3: vertical position
                00 = current
                01 = center
                10 = top
                11 = bottom
             bit 4: don't redraw screen if set
             bits 5-7 not used
        CH = number of columns to offset from position specified by DL
        CL = number of rows to offset from position specified by DL
Return: nothing