some more things i discovered while testing:
Dreamcast:
Flycast standalone -> Analog stick behaves strange: when you move the analog stick slightly to left or right, the directions are recognzied correctly in game, but if you move the analog stick completely (100%) to the right, then it is recognzied as far left direction. And if you move the analog stick completely (100%) to the left, then it is recognized as center. The same seems to be for up and down on the analog stick: if you move the analog stick completely down, then it is recognized as up-direction in the game. And when you move the analog stick completely up, then it is recognized as center.
Flycast standalone -> left and right shoulder buttons of the dreamcast controller are mapped to L1 and R1 of the controller you are using (if it has L1/2 and R1/2 buttons)
Flycast standalone -> Rumble/vibration not working
Flycast standalone -> No Date/Time has to be set
Libretro Flycast -> Analog stick is working correctly
Libretro Flycast -> left and right shoulder buttons of the dreamcast controller are mapped to L2 and R2 of the controller you are using (if it has L1/2 and R1/2 buttons)
Libretro Flycast -> Rumble/vibration is working
Libretro Flycast -> No Date/Time has to be set
Reicast -> Analog stick behaves strange: when you move the analog stick slightly to left or right, the directions are recognzied correctly in game, but if you move the analog stick completely (100%) to the right, then it is recognzied as far left direction. And if you move the analog stick completely (100%) to the left, then it is recognized as far right direction.
The same goes for up and down on the analog stick: with slightly movements the directions are recognzied correctly, but when you move the stick 100% far up, it is recognized as down, and vise versa (moving the stick completely down is recognized as up-direction).
Reicast -> left and right shoulder buttons of the dreamcast controller are mapped to L1 and R1 of the controller you are using (if it has L1/2 and R1/2 buttons)
Reicast -> Rumble/vibration not working
Reicast -> Date/Time has to be set at every start of a game
The issues with Analog Stick behaving strange, does only appear on my Wii U Pro Controller (with PS3 controller the Analog Stick is working fine).
I will test other Controllers i have (Xbox360, Xbox One S, PS4, several 8bitdo) and report, if there are those issues too.