In August 1960, Mr. Diamond and his wife, Joanne Lyon Diamond, were vacationing in Cleveland.

She was having trouble sleeping and visited a clinic there, where she was given thalidomide. She was a few weeks pregnant.

The Diamonds' son Thomas David was born April 6, 1961, at Abington Memorial Hospital with short appendages instead of arms, and multiple medical problems.

In 1962, the Diamonds filed a $2.4 million federal lawsuit against Richardson-Merrell Inc., which produced thalidomide in the United States.

By then, the drug had been withdrawn from the market after reports of deformities in infants born to mothers who had used it as a sleep aid and for morning sickness during pregnancy.

Thalidomide was developed in West Germany in 1954. It was never approved by the Food and Drug Administration but was distributed on a trial basis to 1,200 physicians in the United States in 1960.

In 1969, the Diamonds' suit was settled as it was about to go to trial. The judge ruled that the terms would remain secret "for the protection of these fine parents so they will not be unduly harassed."

Mr. Diamond's younger son, Douglas, said his parents had used the money from the lawsuit for Thomas David's private-school education and occupational and physical therapy.

He said his brother had learned to function with his disabilities and could ski and drive.

Mr. Diamond helped families in Canada, where the drug was widely distributed, reach settlements with Richardson-Merrell, Douglas Diamond said.

Mr. Diamond graduated from Springfield High School in Montgomery County, where he quarterbacked the undefeated football team in his senior year.

He served in the Army Air Force in the Pacific during World War II and was later stationed in occupied Japan.

He earned a bachelor's degree from Lafayette College in Easton, Pa.

He worked for Remington Rand from 1950 to 1955 and then for 10 years was a systems analyst for the accounting firm Arthur Andersen in Philadelphia. From 1969 until retiring in 1999, he owned Diamond Management Systems Inc. in Jenkintown, a provider of accounting and point-of-sales software.

As a young man, Mr. Diamond was a competitive rower, winning singles events locally and at the Canadian Henley Regatta in 1957 and 1958. He was active with the Bachelors Barge Club, a rowing association, and was a member of the Union League and the Huntingdon Valley Country Club.

Mr. Diamond enjoyed hunting in Emporium, Pa., where he and his identical twin, Gilbert, had a log cabin. He and his brother, who died in March, participated in the Duke University Twins Study of Memory in Aging, which researches the causes of dementia. His brother had Alzheimer's disease; Mr. Diamond did not.

In addition to his sons, Mr. Diamond is survived by two granddaughters and his former wife.

A memorial service will be held at 11 a.m. Saturday at Gloria Dei Church, 570 Welsh Rd., Huntingdon Valley, Pa. 19006.

Memorial donations may be made to the church.