There is a software program offered by GE called "Softech" by GE Tools. It will take the series six code and convert it to 9070 code for you. Double check constants in Hex format, we had to clean some values after the code conversion. You may also have to rename some variable names...
I am interested in documentation for an old Mitsubishi PLC, the Melplac 550 is the predecessor to the Melsec line.
I would be greatful for any information leads