The code that used the eeprom was for a aduc834 device. The read/write modbus reg routines were setup so you could have registers with fixed values stored in eeprom (like calibration values etc) and dynamic values stored in ram. You can remove the code that deals with the eeprom or rewrite it to suit whatever eeprom you use (like an i2c eeprom for example). The assembler used was by AD2500 (now Avocet) so you might need to translate the assembler ops I used. Nevertheless, read through the code along with the modbus specification and you'll find it straightforward.