A very rare model unfortunately. I haven't had the chance to work on one and build up some information it. best i can do is point you to a user who has the programming manual:
http://the-checkout-tech.com/manuals/cashregisters/Towa_FX-400_and_Geller_FX-400_operating_and_programming_manual.html
Registerman
February 2013
howtomendit.com for free repair help, information and advice.
