The internal BackupRam is battery powered via a changeable CR2032.
With this mod the Backup will never get lost during battery failure.
You have to replace IC 8 (here a PAL Board 837-12135 PX PD SATURN MAIN VA PAL SD)
with a RAMTRON FM1808-70S and lift Pin 22 and Pin 28. Solder the wires to the lifted pins
Pin 22 to GND
Pin 28 to 5V
and you are done