If you have a Mouse Trapper Advance then the following might be useful for you. It enables the middle button, which is normally the mouse to act as a scroll lock. You can then hold the button down and use the steering pad to scroll around. It's much easier to do this than to try and use the side scrolling.

The method depends if you have libinput or Evdev configured, to find out which one to use, do the following in a shell:

xinput list-props "pointer:Trapper Data Mouse Trapper Advance"

If Evdev is listed in front of the properties, then it's Evdev, otherwise libinput

For libinput:

xinput set-prop "pointer:Trapper Data Mouse Trapper Advance" "libinput Scroll Method Enabled" 0, 0, 1

For Evdev:

device="pointer:Trapper Data Mouse Trapper Advance"  
xinput set-prop "$device" "Evdev Wheel Emulation" 1  
xinput set-prop "$device" "Evdev Wheel Emulation Button" 2  
xinput set-prop "$device" "Evdev Wheel Emulation Axes" 6 7 4 5

If you want to make things permanent, put the above in the \~/.xinitrc file

Note:

The middle mouse button is still available as before so long as you press it for a short time and don't hold it down.