This is part of Family API which allow to create dual-os version of program runs under OS/2 and DOS
Note: This is legacy API call. It is recommended to use 32-bit equivalent
This call deregisters a alternate video subsystem previously registered within a session.
VioDeRegister()
rc (USHORT) - return:Return code descriptions are:
VioDeRegister must be issued by the same process that issued the previous VioRegister. After VioDeRegister is issued, subsequent video calls are processed by the Base Video Subsystem.
#define INCL_VIO USHORT rc = VioDeRegister(VOID); USHORT rc; /* return code */
EXTRN VioDeRegister:FAR INCL_VIO EQU 1 CALL VioDeRegister Returns WORD