Mr. Walden eventually enrolled at San Francisco State College (now university) and received his bachelor’s degree in mathematics in 1964. His interest in computer science grew through a numerical analysis course he took on an IBM computer.
After college, he went to work for the Lincoln Laboratory at the Massachusetts Institute of Technology as a computer programmer in the Space Communications Division.
In 1965 he met Sara Elizabeth Cowles, an education clerk, and they married the following year. He was hired by Bolt Beranek and Newman in 1967. Shortly after, the company won a contract to build the first IMP.
“It was a very small group that worked together all the time,” Mr. Walden said in a 1990 interview with the University of Minnesota’s Charles Babbage Institute, an archival and research center specializing in information technology.
“We were in and out of each other’s offices, helping each other debug,” he added.
Each discovery sparked excitement. “We’d run in and say, ‘Look, I’ve got this spinning!'” he said.
Mr. Walden left Bolt Beranek in 1970 for a year to join Norsk Data and helped that company build a computer modeled on the IMP. He returned to Bolt Beranek in 1971 and stayed there until 1995. He later became an expert in management. An avid computer historian, he edited the IEEE Annals of the History of Computing, published by what was originally the Institute of Electrical and Electronics Engineers.
Although he did not hold a senior degree, Mr. Walden received an honorary doctorate from California State University in 2014 for his work at Arpanet. “He has told me more than once that he never thought he would receive such an honor,” Alex McKenzie, a former colleague of Mr Walden’s, said in an interview.
Besides his wife, Mr. Walden leaves behind his son Luke; his brother, Daniel; his sister, Velma Walden Hampson; and two grandchildren.
