Question: how to open dsp file?
Answer: You're here because you have a file that has a file extension ending in . dsp. ... 
The content of a Visual C++ 6 project file is encoded in the DSP format, and these DSP files can be created, opened and edited with the Visual C++ 6 application. ... 
Launch a .dsp file, or any other file on your PC, by double-clicking it.