S-1 Supercomputer (1975-1988)
(below: Lowell Wood)
".. at Livermore, Lowell [Wood] asked the graduates students [Tom McWilliams and Curt Widdoes] to team up and give some thought to designing a supercomputer from scratch."
-- William Broad, Star Warriors, p. 32
The project was envisioned by Lowell Wood at the Lawrence Livermore National Lab in 1975 and staffed for the first three years by two Stanford University Computer Science graduate students, Tom McWilliams and Curt Widdoes.
That two graduate students could design and almost completely build a supercomputer by themselves is an amazing feat, comparable to the design and building of the CDC 6600 by Seymour Cray and a small staff a dozen years earlier.
However, McWilliams and Widdoes are even better known for the major advances in CAD tools for logic design that they developed as part of the early days of the project and for the startup company they founded, Valid Logic Systems.
The project was supported by the US Navy and ramped up in 1978 with the addition of more students, including Mike Farmwald and Jeff Rubin, and again in 1979.
Dr. Carl Haussman provided the day-to-day oversight as the project team grew in size.
Five generations of S-1 processors were planned, and two MSI/ECL generations were built.
The project independently invented two-bit branch prediction, directory-based cache coherency, and multiprocessor synchronization using load linked and store conditional.
The project also influenced the development of programming languages and compilers including Common LISP and gcc.Dr. Lowell Wood, a physicist at LLNL and protege of Edward Teller, led the special studies group at LLNL, which was called the O-Group.
The O-Group members had many interests, but their work mainly revolved around ideas for a national missile defense.
Wood was also an interviewer for the Hertz Foundation, which awarded prestigious scholarships to graduate students interested in the applied sciences.
From this position, Wood could occasionally recruit top students to work at the lab.
Two Hertz Foundation scholarship recipients, Tom McWilliams and Curt Widdoes, enrolled in the Ph.D. program in computer science at Stanford in 1975 and came to work with Wood at LLNL.
Wood challenged them to design and build a supercomputer.
In fact, Wood envisioned a family of multiprocessor supercomputers, with each having nodes of comparable power of contemporary commercial supercomputers.
The plan was to build five generations of processors with the same general architecture and to develop computer-aided logic design tools that would ease the task of reimplementing the processors in each new logic technology family.