Visual C++ and Assembler
Visual C++ is a much more robust programming language then Visual Basic by allowing us to create not only executable programs, but Active X controls and Dynamic-Link Library's (DLL's).

An example of a DLL we created are those that go with the Visual Basic telephony project, PhoneLink. By creating a common user interface to the routines contained in the DLL we created a bunch of different DLL's, each to be used for a different environment. Some of the different DLL's created communicate:

• via the serial port using:
  
  • the Hayes AT command set, and
    
  • phone specific command sets for the Rolm, Telrad, and AT&T phones.
  
  

• via a network using:
  
  • Microsoft's TAPI,
    
  • Novell's TSAPI, and
    
  • a server specific database design.
    

And there is an ongoing effort to handle more and different types of hardware to broaden PhoneLink's market.

Since each one of these DLL's handles one type of hardware environment, it is a simple matter to ship out the correct DLL with the PhoneLink product to a customer. If the customer upgrades or changes hardware in the future then a new DLL is all that is required to keep them up and running.