Availble for download as kits and not as virtual machines on Microsoft’s msdn site Visual Studio 2010 .NET Framework 4 Beta 1 Download link http://msdn.microsoft.com/en-gb/netframework/dd819232.aspx
One of the greatest tools for testing TAPI is the old software TB20.exe Microsoft description: TB (TAPI Browser) is an application that allows a user to interactively call into the Windows Telephony interface and inspect all returned information. Becouse this application is not availble anymore on Microsoft site and is very hard to find on [...]
char[(n)] Fixed-length non-Unicode character data with length of n characters. n must be a value from 1 through 8,000. Storage size is n bytes. nchar[(n)] Fixed-length Unicode character data with length of n characters. n must be a value from 1 through 4,000. Storage size is two times n bytes. varchar[(n)] Variable-length non-Unicode character data [...]