This subfunction cannot be used unless both video adapters have a disable capability (Int 10H Function 12H Subfunction 32H).Allows selection of one of two video adapters in the system when memory usage or port addresses conflict between the two adapters.
Call with:
AH = 12H
AL = switching function
00H to disable initial video adapter
01H to enable system board video adapter
02H to disable active video adapter
03H to enable inactive video adapter
BL = 35H
ES:DX = segment:offset of 128-byte buffer (if AL = 00H, 02H, or
03H)
Returns:
If function supported
AL = 12H
and, if called with AL = 00H or 02H
Video adapter state information saved in caller's buffer
or, if called with AL = 03H
Video adapter state restored from information in caller's buffer
Notes:
This subfunction cannot be used unless both video adapters have a disable capability (Int 10H Function 12H Subfunction 32H).
If there is no conflict between the system board video and the adapter board video in memory or port usage, both video controllers can be active simultaneously and this subfunction is not required.