As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ABOVE 2 HRS INTO FLT AT 38K WE HAD AN ALT DISAGREE CAUGHTION MSG. WE DETERMINED THE F.O.'S WAS INCORRECT. IT WAS ABOUT 250-260 FT ABOVE THE CAPT'S AND ABOUT .01 DIFFERENCE IN MACH NUMBER ++ REMOVED AND REPLACED R/H ADC IAW MM CHT 34-12-01 OPS CKS GOOD QD'S WERE PRESENT.