Technology History | Chippewa Falls — Serial Number One Came Home

The Cray-1 in this museum is serial number 001, and it is back in the town that built it.

Seymour Cray was born here in 1925 and kept returning. He opened a Control Data laboratory in Chippewa Falls in 1962, and when he left CDC in 1972 to start Cray Research, he put the research and the manufacturing here again.

The Cray-1 was announced in 1975. Serial 001 went to Los Alamos National Laboratory in 1976 as a test system, on trial, before anyone had agreed to buy one.

Its shape is the argument. Electricity takes time to cross a wire, so Cray bent the cabinet into a C to shorten the longest connections inside the machine.

The ring of padded benches around the base is not seating.

It hides the power supplies and the cooling plumbing, and in 1976 Computerworld called the result the world's most expensive love seat.

Eighty megahertz, 160 megaflops, roughly eight megabytes of memory, five and a half tons.

It was the first supercomputer to make vector processing actually work, which is a narrower claim than it sounds. The CDC STAR-100 and Texas Instruments' ASC had both implemented the idea earlier and both were crippled by how they did it.

Cray Research passed to Silicon Graphics in 1996, to Tera Computer in 2000, and to Hewlett Packard Enterprise in 2019.

Chippewa Falls survived every one of those changes. HPE committed $22 million to the site in 2021 and named it a manufacturing centre of excellence for high performance computing.

Machines for the American exascale programme are still built in this town.

Seymour Cray died in 1996, and the highway running past the plant was renamed Seymour Cray Sr Boulevard.

Serial 001 travelled once more in 2018, on loan to the SC18 conference in Dallas for the meeting's thirtieth anniversary, then came back to the museum.

In April 2026 the United States Mint issued the Wisconsin American Innovation dollar with a stylized aerial view of the Cray-1 on the reverse. Reviewers sent the design back to be redrawn so the number of wedges matched the real machine.

The cover photograph shows a Cray-1 displayed at EPFL in Lausanne, not the museum's serial 001.

Photo: Rama, CC BY-SA 2.0 fr, via Wikimedia Commons.