Hello, PM answered.
I did not test every function of the external controller port but I can tell you by having feedback from differents customer that is :
- ok with a classic 2 buttons pad (tested myself)
- ok with a 6 buttons pad with strange behavior when street fighter is on a everdrive (i dont have a 6 buttons controller to test)
- ok with a multitap, if you are crazy, you can play bomberman on a 2.4" screen with 5 friends
(tested with 2x 2buttons controllers only).
- ok with blueretro and a bluetooth controller on 6 buttons mode, and blueretro allows you to play with 5 controller connected to a single unit.
The hardware of the PC Engine GT is the same as the Core.
The controller board I made have the same components as a classic 2 buttons controller, the same schematics is used.
4 diodes are here to bypass conflict between the board and the external controller connector.
I think external controller mod could be useful coupled with a external A/V mod. The screen is small, ok to play alone, but 2 dudes on the same 3.5 screen could be difficult.