Inside Macintosh: Devices /

Chapter 6 - Power Manager / Power Manager Reference

Power Manager Routines / Controlling Serial Power

BOn

You can use the BOn procedure to turn on the power to serial port B.

PROCEDURE BOn;

DESCRIPTION

The BOn procedure switches on power to the SCC, the -5 volt supply, and the serial driver chips.

ASSEMBLY-LANGUAGE INFORMATION

The MPW development system provides an assembly-language macro to execute the BOn routine. That macro calls the _SerialPower trap. To call the _SerialPower trap directly, you must first put a longword routine selector in the D0 register. For BOn, the routine selector is $0.