Legacy Document

Inside Macintosh: Networking /

Chapter 2 - AppleTalk Utilities / AppleTalk Utilities Reference

Routines / Opening and Closing Drivers

MPPOpen

If the .MPP driver has not already been opened, the MPPOpen function opens
the .MPP driver, initializes the driver's variables, and assigns a node ID to the
Macintosh computer.

FUNCTION MPPOpen: OSErr;

DESCRIPTION

The MPPOpen function first determines whether the .MPP driver has already been opened. If it has, MPPOpen returns an error code. If the .MPP driver is not open, MPPOpen loads the driver into the system heap and then initializes the driver's variables before dynamically assigning a node ID to the system. It also loads the .ATP driver
and the NBP code into the system heap.

Apple Computer, Inc. recommends that you use the Device Manager's OpenDriver function to open the .MPP driver instead of using the MPPOpen function.

SPECIAL CONSIDERATIONS

For versions of AppleTalk before AppleTalk version 56, if serial port B isn't configured for AppleTalk or if it is already in use, the .MPP driver is not loaded and the portInUse result code is returned.

RESULT CODES

noErr	0	No error
portInUse	-97	Driver open error code indicating that the port is in use
portNotCf	-98	Driver open error code indicating that the parameter RAM is not configured for this connection

SEE ALSO

The MPPOpen function does not return the .MPP driver reference number, as the OpenDriver function does. For information on the OpenDriver function, see
the chapter "Device Manager" in Inside Macintosh: Devices.