MAME MorphOS supports joypads just fine, but you also need to configure the bindings in MAME options (press tab during game and go to player1 or general, and define the bindings there).
Tried doing that. It's as if some kind of "bridge" is broken between MAME and MorphOS. Machine does not accept joystick or control pad input through MAME.
Looking at Morphzone.org, I see someone had the same problem as me, waaaay back in 2003!
"Basically there are 2 choices of how to configure a USB gamepad.
Either you map (some) controls to be accessible via lowlevel.library, or you map them to the keyboard.
There aren't THAT many morphos-compatible games that support joystick control via lowlevel.library without any keyboard support."
...doesn't seem as if the settings take when making adjustments in lowlevel.library. I tried selecting the 'mapping' feature in selected actions to no avail also, thinking I could map keyboard presses to joystick 1 - duh, but it does not work that way. Also tried switching all button and directional presses to 'push' instead of 'assign' and while the actual buttons are not recognized in MAME's config, the digital pad is. But it's actions are way off. When I enter MAME's config screen and try to tell it a simple 'up' command from my pad, it accepts it right away as 'up joy 1', but then the cursor scrolls continually up until I press down on the pad. Sometimes it's more out of control than that.