X68000 Trackball?

[dos]

It says here that some games like Syvalion support a trackball. Are there trackballs specifically made for the X68K that plug into the mouse port? I don't have a mouse for my setup so I can't test it with a mouse but I'm wondering if the X68K trackball is something that connects to the joystick port or mouse port, and if something like the Master System trackball or an Amiga/Atari ST/etc trackball can be used?

[NFG]

The original X68000 mouse was a trackball.  See below.  =)

[caius]

Hi, some model of X68000 mouse are also trackball (they don't have a real ball but act as a trackball), I have this and worls very well:

[dos]

Oh neat so that rounded part up top can be used like a trackball? Does it work as a normal mouse as well? I was more wondering about this sort of trackball though:



Just wondering if there are any known "real" trackballs compatible with the x68k.