> does anyone know how to update OBP on the SS10 ?

Well it is either a EPROM or EEPROM (I'm not sure about the later 
machines but SS2 and IPC had EPROM) and cannot be software upgraded, but 
need to be taken out of the machine and put in a programmer. You can get 
firmware images from http://www.sunshack.org/data/bootroms.html

Olev