Well, after a fair bit of searching I’ve found the mapping details on github that tend to suggest that only two virtual joysticks can be mapped using Dosbox. I guess that answers that – still I’ll try with the USB hub and hope I’m reading this wrong. Failing that: is there more than a couple four player games that would make me digging into this worthwhile?

I’ve been trying to get Micro Machines 2 going. It won’t emulate on Snes9x so I can’t play 4 player there, and all other emulators for the platforms it’s on won’t handle multitaps etc. the DOS version has the option of playing 4 people with two on keyboard, and while DosBox has a fantastic controller to keyboard mapping system the controller input that runs it just isn’t setup to receive input from more than two USB controllers.

It seems obvious enough to patch in the files but I just don’t have the raw skill/confidence to do it yet, and even if I did it’s a very rare case for extended functionality :)

Actually I updated to RetroPie 3.1 last night and the emulation issues I was getting on the SNES seem to have been resolved, but thank you for helping out!!!