Selects an alternate map register set or (if alternate sets are not supported) restores the mapping context from the specified buffer.
Call with:
AH = 5BH
AL = 01H
BL = alternate register set number or 00H
ES:DI = segment:offset of map register context restore area
(if BL = 0)
Returns:
If function successful
AH = 00H
If function unsuccessful
AH = error code
Notes:
The buffer address specified in this call is returned by subsequent calls to Int 67H Function 5BH Subfunction 00H with BL = 00H.
The save area must have been initialized by a previous call to Int 67H Function 4EH Subfunction 00H.
This function is intended for use by operating systems only and can be disabled by the operating system at any time.