Running DK Remix (CoCo3 version) in Retropie via MESS?

[PrincessMonacoOfKent]

Has anyone had any luck with this? I can get it to boot up no bother and start a game, but for some reason the controls are completely screwy - right and jump work fine, but up on the joystick is left and nothing appears to work for up, so you can't climb the first ladder.

Other CoCo games have no problems, joystick works normally. And the DSK file I'm using works perfectly in PC emulators like MAME, just not in Retropie.

What's weirder still is that the controls work in the pre-game menus - up is up, down is down etc. And if you change the Analog Stick controls in the MESS menu (so that left is up etc), it doesn't change anything at all in the game - you still have to push the stick up to go left.

I'm baffled.

[Sock Master]

Retropie might be based on an older version of MAME/MESS.  When the CoCo3 conversion of Donkey Kong first came out, MAME/MESS also had issues emulating the joystick in that game.  Later versions of MAME/MESS fixed the issue.

What happens is, the game uses aggressive coding to squeeze as much performance as it can out of the hardware - even the joystick routine is coded to be as fast as possible.  Signals are sent out the joystick port and XX cycles later they come back and are read to determine if the joystick is at a certain position.  The in-game joystick routines read the returned signal sooner than most other joystick routines.  This works fine on real hardware, but older versions of MAME/MESS did not update the signal as quickly as real hardware did and the game gets false joystick readings in those versions of MAME/MESS.

[PrincessMonacoOfKent]

Cheers for that, will see if I can find more up-to-date versions.