Assuming you are using CCP and are updated or MX900 stand alone and are updated, the RX-V77x should work just fine. The codes are basically the same within the RX-V series, as long as you don't go back too far like the RX-V1600. Even most of those codes are the same, but I am thinking yamaha changed the input names. I could be confusing the RX-A series.
