As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO TOP OF DESCENT, CAPT IAS SHOWED A 30KT OVERSPEED WITH ATTENDANT WARNINGS, EICAS MESSAGES FOR RUDDER RATIO AND MACH SPEED TRIM F/O AIRSPEED INDICATOR DID NOT SHOW AN OVERSPEED. PITCH AND POWER CONFIRMED. EMERGENCY DECLARED. CAPT AIR DATA COMPUTER REPLACED, TESTED SERVICABLE IAW AMM 34-12-00-5. LOW LEVEL CHECK CARRIED OUT SERV IAW MM 34-11-00-5. SEE LP 347116/1 FOR REPLACEMENT OF RT ADC.