What was “Radar” O’Reilly’s real name in the 1970 film and 1972-83 CBS TV series “M*A*S*H*”?

“Radar” O’Reilly’s real name in the 1970 film and 1972-83 CBS TV series “M*A*S*H*” was Walter.

Gary Burghoff played the character in both TV and film.