Legacy Document

Inside Macintosh: Devices /

Chapter 6 - Power Manager / Power Manager Reference

Power Manager Routines / Controlling Serial Power

AOnIgnoreModem

You can use the AOnIgnoreModem procedure to turn on the power to serial port A but not to the internal modem.

PROCEDURE AOnIgnoreModem;

DESCRIPTION

The AOnIgnoreModem procedure switches on power to the SCC, the -5 volt supply, and the serial driver chips. This procedure does not switch on power to the internal modem, even if the user has used the Portable or PowerBook control panel to select the modem.

ASSEMBLY-LANGUAGE INFORMATION

The MPW development system provides an assembly-language macro to execute the AOnIgnoreModem 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 AOnIgnoreModem, the routine selector is $5.