SMS games that don't work with genesis controllers

[Jedi Master Thrash]

SMS games that don't work with genesis controllers

This is quite an odd one.

A couple of new SMS games I picked up won't work with genesis controllers (3-button or 6-button).

I verified I wasn't going crazy, and all the SMS games I already owned do work perfect with genesis controllers. But two of these new ones don't.

Shanghai will only register up and down on the d-pad. It ignores left and right.

Penguin Land acts as if you always have the left d-pad pressed and it doesn't register any other directions.

I checked, and the games work fine with a true Master System controller.

Any ideas? What minor difference is there between the Master System and Genesis D-pads that catches these two games?

FYI, I'm using the Power Base Converter to play.

I haven't even found a 2600 game yet that doesn't work with the genesis pad.

Thanks,

JMT.

 

[ExCyber]

SMS games that don't work with genesis controllers

Alien Syndrome doesn't work with a Genesis pad either. There's a list of 10 or so games in the Power Base Converter manual if memory serves, although that's more of a "don't work for whatever reason" list that includes e.g. F-16 Fighting Falcon (which doesn't work because it uses undocumented SMS VDP modes that aren't supported by the Genesis VDP). AFAIK the problem is that these games write to the controller port for some reason and trigger the signal that switches between the two sets of buttons that the Genesis controller reports (set one being Up, Down, Left, Right, B, and C; set two being Up, Down, A, and Start, with the Left and Right buttons reporting as pressed). 2600's controller ports are input-only, so you won't see this problem, although it's kind of weird that it would work on 2600 since it puts Vcc on pin 7 rather than pin 5. Maybe pin 7 is supplying Vcc through a pull-up resistor in the controller, though...

edit: from reading Charles MacDonald's SMS notes, the "some reason" seems to be region detection; apparently there's a difference in how Japanese and US models latch and/or allow readback of pins set to output on the controller port.