SEATTLE (AP) _ Walter H. Brattain, who shared the 1956 Nobel Prize in physics for discovering the transistor, died today of Alzheimer's disease at a nursing home. He was 85.

Brattain, John Bardeen and William Shockley, all research scientists at Bell Telephone Laboratories at Murray Hill, N.J., shared the physics prize for their research in semiconductors and the discovery of the transistor effect in 1947. Shockley later became known for his controversial theories on genetics.

The men's research gave birth to modern electronics, revolutionizing technologies in space exploration, satellite communications and computers. It led to the transistor radio and improved televisions and telephone service.

Brattain was raised and educated in Washington state, and received a bachelor's degree from Whitman College in Walla Walla in 1924, college spokeswoman Elaine Prentice said.

He served as a visiting lecturer at Harvard University and at the universities of Minnesota and Washington, and received honorary doctor of science degrees from numerous schools, including Whitman.

He was a visiting lecturer and professor at Whitman from 1962 to 1972, and later served as a consultant there.

Brattain was elected to the National Inventors Hall of Fame.

His funeral will be in Pomeroy, but no date or time has been set, Ms. Prentice said.