I did JagPad support:
Basic hard disk version:http://atari.8bitchip.info/TestMe/PRE5.ZIP
Haga version (good for Falcon) :http://atari.8bitchip.info/TestMe/OIDSJP.ZIP
Improved fire too, for easier single shot.
JagPad, PowerPad buttons:
Hat - Thrust, rotation <>, shield on/off.
Fire A - Gun
Fire B - Novabomb
Fire C - Shield recharge
Pause - Pause on/off - but any button will unpause
Now, some longer explanation:
This game uses some more complex controls than simple fire button press, jump press and like. For instance Novabomb can be activated by releasing button in proper moment. That means that there must be detection of exact key/button release moment.
But TOS functions for reading keyboard, joystick have no functions to detect exact moment of release - not even moment of press. That's why it must have own, custom input reading code. And it is based on keyboard keys position in matrix, and not on letter - what may be Y or Z, depending on language. So, we don't have here any use of programmable keys for game. Actually, I plan to remove from this version all keyboard codes for controls possible to do with joystick and JagPad - they are pretty long, and just slow down without any use. What is possible is to make different layout for play control buttons, if above is not good. I tested only in Steem, with pretty different Gamepad. That is not so hard. Reading JagPad is not hard. What was hard is to inject JagPad commands in proper locations in code, in proper way. Especially Pause was problematic.
Part of problem is in fact that in Atari STE keyboard, joystick, mouse - so what goes via IKBD chip work on interrupt generation base - when some change happens - like pressing or releasing key, button - interrupt is generated, and SW can read code of action. JagPad is different - it is simple port, and you can only read it periodically in SW.
To add that you will see that JagPad does not work in Galaxy selection - while it is possible with joystick. Yes - because another code is used for it, and not what in gameplay. Don't see that it is worth to add there JagPad support too.
Let me know hot it works with real HW. Want any better layout ? - but without kb. remapping - just gimme function, and to which JagPad button to assign.