I do not understand the posted instructions on how to use 64DD content with Mupen.
I have found these instructions:
"First, you need a BIOS file. Make sure the file ‘IPL.n64’ is located in your /Mupen64plus directory.
You can either use the subsystem for 64DD, or you can name the disk image the same as the ROM including extension.
If you need to load a specific cart with the Disk image, that would be: “homebrew.n64” and “homebrew.n64.ndd” then Load Content “homebrew.n64”."
I have done ALL of this and it does not work.
If anyone can help, I would appreciate it very much.