You can try the following web site for a manual:
http://www.royalsupplies.com/drivers-manuals.html
You also might try resetting the register to clear the error. To do this
1) Unplug the register from the power outlet.
2) Turn the key to the PRG position.
3) Plug the register back in to the power outlet.
4) Turn the key to REG.
Good luck ...
Steve
October 2009