This call returns the current mode of the processor, whether the processor is running in the DOS mode or the OS/2 mode. This allows an application to determine whether a dynamic link call is valid or not.

DosGetMachineMode (MachineMode)

• MachineMode (PBYTE) - output: Address of the value to indicate the current processor mode. This value may be:
  • 0 - DOS (real) mode
  • 1 - OS/2 (protected) mode.

• rc (USHORT) - return

Return code description is:

• 0 NO_ERROR

All dynamic link calls are available to an application if the MachineMode value indicates the program is in OS/2 mode. This method provides a self-tailoring application that allows the application to adapt to the execution environment by limiting or enhancing the functions it provides.

If the MachineMode value indicates the program is in DOS mode (or real), the application is limited to a subset of dynamic link calls listed in the Family API.

#define INCL_DOSMISC

USHORT  rc = DosGetMachineMode(MachineMode);
PBYTE   MachineMode;   /* Processor mode (returned) */
USHORT  rc;            /* return code /*/

EXTRN  DosGetMachineMode:FAR
INCL_DOSMISC      EQU 1

PUSH@  BYTE    MachineMode   ;Processor mode (returned)
CALL   DosGetMachineMode

Returns WORD

Text based on http://www.edm2.com/index.php/DosGetMachineMode