One jumper (J1) is intended to inform the board the FPU is clocked by the same crystal of the CPU, or from a different one.
The other jumper (J2) is there for factory settings (don't mess with it!). If you do so your Amiga will explode, your hair will fall, your dog will scape, your wife gonna fat, etc, etc. Kidding, just don't mess with this little fellow (J2), keep it open.
Those boards only need the software to add RAM when use ks3.0.
The dual boot is when you use the software "autoxa" (some sort of rekick), supplied with the board. Who copy the ROM contents to RAM, trap the vectors and reboot.
