DDS function generator MOTECH FG503

[RayeR]

Hi,
I have repaired one old function generator MOTECH FG503. I dumped all programmable ICs and explored program memory. From what I've seen I come to conclusion that this device have some calibration menu or protocol, probably via RS232 or LCD. But I don't know how to access it as I don't have any documentation and software. It is impossible to find any resources than brief specification of this device - please do have anybody something more?
Anyway I was able to find some calibration values in EEPROM and created partial data map. It may interest other users of this device. I wrote an article, it's CZ lang only - you can use google translato: http://rayer.g6.cz/elektro/fg503.htm
The EEPROM map table has description in english.