Leon, that's right, Dude. The IFF panel in the cockpit was replaced - so modes1-4 and C were all on the same box. Also all the old transponders and (part of the) interrogators had to be replaced. One of the reasons it wa a bit of a rushed job. I still say we were better of with it, albeit rushed, than without it, or to have waited to have a complete and fully tested integration.
Just my personal view.
Courtney