TAPI is the easiest way of doing it in Windows. Is there a good reason for not using it. (Apart from poor TSPI support for your telephony device) This old Slashdot article discussed Telephony and Linux there may be some useful links[^] Michael 'Logic, my dear Zoe, merely enables one to be wrong with authority.' - The Doctor: The Wheel in Space
http://www.codeproject.com/useritems/interrupthook.asp[^] is for raw interrupt hooking, and to setup an interrupt handler, you'll need to use the kernel-mode api IoConnectInterrupt! Don't try it, just do it! ;-)