I have several Tatung Heron+ SBUS frame buffers
for the Sun's... they have a Sun TurboXGX chip
on them, and I presume they are Tatung clones of
the Sun TGX boards.  

I notice they have a little rotary switch on the
board near the faceplate.. does anyone out there
know what the switch is for, or have any docs on
these boards?

Pete