Although the designs were never finished and no models ever went into production, the project spawned a number of organizational techniques and architectural innovations that have since become incorporated into nearly all high-performance computers in existence today.
Gene Amdahl took the opportunity to start his own company, building IBM-compatible mainframe computers using the ECL designs worked on for ACS.
They had to withdraw it from the market when tests at the launch customer, Los Alamos Scientific Laboratory, demonstrated it had very poor real-world performance.
[1] In the spring of 1962, Control Data Corporation (CDC) announced that they had installed two computers at Lawrence Radiation Laboratory and had received a contract for a third, a much more powerful design.
Bertram brought in John Cocke, Frances Allen, Brian Randell, Herb Schorr, and Edward H. Sussenguth, among others.
Schorr developed the initial instruction set and recruited his former student, Lynn Conway, to work on a system simulator.
Watson was convinced that the 360 instruction set would not be suitable for the new design and was worried that development would be slowed by the turmoil at the labs due to the 360 problems.
[3] Harwood Kolsky gave a presentation on the various competing designs, while Gene Amdahl and Chen Tze-chiang talked about their work on the high-end 360 Model 92.
As a Fellow, Amdahl was entitled to work at any IBM facility of his choosing and decided to join ACS at the invitation of Bob Evans.
While it might run marginally slower than the ACS, due largely to it using a 32-bit word and having 16 registers instead of 32 48-bit ones, it would offer customers of the Model 92 an upgrade path to much higher performance and leverage all of the software and especially their compiler technology developed for that machine.
In 1966, a new building with 38,000 square feet (3,500 m2) was built at 2800 Sand Hill Road in Menlo Park, California, near the Stanford Linear Accelerator and the project moved there late in the year.
Reviewing the system, Schorr and Dick Arnold concluded it would not work, and decided to reimplement it as a single-level with hardware caching of 32 or 64 kWords.
In comparison to the 7090, IBM's older scientific offering, ACS-1 would perform the Lagrangian Hydrodynamics Calculation (LHC) 2,500 times faster.
Among its features was the ability to unwind loops, schedule instructions around the basic block concept, and separate those optimizations that were code-based vs. platform-based.
In January 1967, Ralph L. Palmer asked John Backus, Robert Creasy, and Harwood Kolsky to review the project and Amdahl's concept.
The ACS team responded with a "frantic" redesign that reduced the number of gates from 270,000 to 200,000 with little effect on performance, which strongly suggested it was overdesigned.
But a key point made by Conti was that if the ACS system was so reliant on the compilers for its performance, moving that code to some other machine could result in far different outcomes and that could be considered a disadvantage.
"[11] Although the ACS would have outperformed the Model 95 by a wide margin, by this time Watson Jr. was considering withdrawing from the supercomputer market entirely.
IBM faced a similar problem with Stretch, but over time it was shown that the R&D in that project had been widely used in the company and if it was billed out then it was slightly positive.
[13] What had initially been intended to be a project to compete with the fast-moving CDC had now stretched on for the better part of a decade and showed little evidence that it would release a machine in the short term.
[14] When the ACS project was cancelled, many of the engineers were not interested in returning to the main IBM research campus in New York and wished to remain in California.
Some ended up at IBM's hard drive research facility in San Jose, California, while many others left to form a new company, Multi Access System Corp, or MASCOR.