Enables the operating-system—specific EMM functions (Int 67H Functions 59H, 5BH, and 5DH) for calls by any program or device driver. (This is the default condition.)
Call with:
AH = 5DH
AL = 00H
BX:CX = access key (if not first call to function)
Returns:
If function successful
AH = 00H
BX:CX = access key (if first call to function)
If function unsuccessful
AH = error code
Notes:
An access key is returned in registers BX and CX on the first call to Int 67H Function 5DH Subfunction 00H or 01H. The access key is required for all subsequent calls to either function.
This function is intended for use by operating systems only.