The type is irrelevant
I disagree. Not all aircraft that are fitted with TCAS have an Inertial Reference System.
Also, I imagine, although I don't have any data to hand, that the set-up of a Boeing's Avionics and an Airbus' are miles apart and where TCAS takes the inputs from will differ.
It would seem from the post above regarding the A320, that TCAS takes inputs from ADIRU #1. It would be interesting to know if there is any redundancy where TCAS is concerned. I.e. If ADIRU #1 fails, is the system capable of supplying data to the TCAS Computer from another ADIRU?
If not, then as I said in my previous post, the TCAS system will fail.