I have mame running but I'm having a problem understanding the key configurations for two of my fav games.

cloak and dagger and robotron.

Yep those two joystick combo games.

Everytime I try to reconfigure the fire keys I get some weird combo's like down becomes up and on cloak and dagger the one key triggers the igniter and a fire direction.

I've tried various combos but somehow it doesn't come out right

can someone explain how the key configs in mame work?

Moving to the MAME forum ...

And now, to help:

Here's how I set up Robotron:

Fire 1 = A
Fire 2 = Y
Fire 3 = X
Fire 4 = B

... this setup works for any dual-joystick type control, like Black Widow for example.