WRT elucidation of what the ACARS messages meant in detail from our esteemed colleagues earlier. I gather the ISIS fault may have resulted in loss of ATTitude information from the standby instruments. Someone said they would try to work out exactly what would have been lost from the PFD - but I haven’t seen any post in relation to it since. I believe that IRU’s continue to send valid data if faults only lie with AD part of ADIRU’s. Presuming that main displays loose airspeed , possibly ALTitude also. But would they still have had ATTitude cues on main displays?