AOnIgnoreModemYou can use the
AOnIgnoreModemprocedure to turn on the power to serial port A but not to the internal modem.
AOnIgnoreModemprocedure 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 INFORMATIONThe MPW development system provides an assembly-language macro to execute the
AOnIgnoreModemroutine. That macro calls the
_SerialPowertrap. To call the
_SerialPowertrap directly, you must first put a longword routine selector in the D0 register. For
AOnIgnoreModem, the routine selector is $5.