Has anyone out there heard of activating the flip on a 8390 so that when using a 6500 OEM faceplate, the flip answers and disconnect calls?

With the OEM 6500 faceplate, all the hardware looks like it is there (contacts on the phone and faceplate) so maybe its just an issue of hacking the firmware to make it functional?

Just a question as I am a complete newbie to phone programming....