Programming support is furnished by Microsoft. The Digi device driver supports the Microsoft 32 bit COMM API. If your application supports the 32 bit API, then it should work with the Digi AccelePort product.
Most customers have programming problems resulting from port initialization, and not understanding the difference between a non-intelligent port, and a buffered intelligent port like on the AccelePort products.
There is a good article titled "Serial Communications in Win32" on the Microsoft website which includes sample code. It can be found at:
There is another good serial programming guide that can be found at: