What are TAPI and TSAPI?
Normally, your software retrieves the Caller ID data by opening up the COM port and waiting for the telephony hardware to send the data when a call comes in. The trouble with this is that no other program can access the COM port whilst the Caller ID program is running. This is very inconvenient if you want to use your modem for connecting to the Net, for example. For this reason, Microsoft introduced TAPI, the Telephony API. This acts as a middleman, brokering access to the modem by all the program that want to use it. This allows you to use Dial Up Networking without closing down your Caller ID program first, if your Caller ID program is TAPI-compatible. So it’s a good idea to make sure that your Caller ID program is TAPI compliant. I’ll come back to the subject of TAPI in the section on writing your own programs, but for the moment here’s a run down on all the different versions : TAPI 1.3/1.4 was the 16bit/32bit hybrid version that came with Windows 95; NT 4.0 introduced the fully 3
