How develop 6503 and serial port without DAQAssistant

[初学者]

My DaqAssistant cann't run normally, so I want to konw how to program 6503 using C# without daqAssistant. I want to develop serial port in C#,but there is no comm control in VS2003. Moreover, can I drive a oscillograph through serial port in C# using VISA? Thanks for answering me!

[初学者]

find a example code for DO  in the MS directory.

There is no code for serial port.