Character keeps going in one direction

[mzbab88]

Does this game works for you? http://www.whatisthe2gs.apple2.org.za/immortal-the

For me, that wizard keeps going down-right when nothing is pressed. People tell me to calibrate my joystick, but I'm not sure how to do it on windows 7. Had the same thing with ActiveGS. My joystick is very simple, 4 direction buttons, no sticks, 10 other buttons. Seems to work somewhat okay in other (not ][gs related) games, so it looks like an emulator bug.

I also have very little idea what those parameters in F4 -> Joystick Configuration are supposed to mean.