IBM-ACS: Reminiscences and lessons learned from a 1960’s supercomputer project

By Lynn Conway

Professor of Electrical Engineering and Computer Science, Emerita

University of Michigan, Ann Arbor, Michigan

[Version of 5-28-11]



Online table of references, with links:


[CAL58] S. H. Caldwell, Switching Circuits and Logical Design, John Wiley & Sons, 1958; See especially: Chapter 7: Symmetric Functions, p. 236-274; Chapter 8: Synthesis of non-series-parallel contact networks, pp. 274-318.


[LEE62] D. N. Leeson and D. L. Dimitry, Basic Programming Concepts and the IBM 1620 Computer, Holt, Rinehart and Winston, 1962.


[WIL63] M. V. Wilkes, "An Experiment with a self-compiling compiler for a simple list-processing language", Tech. Memorandum No.63/1, University Mathematical Laboratory, Cambridge University, Feb. 1963.


[WIL63-2] M. V. Wilkes, "An Experiment with a self-compiling compiler for a simple list-processing language (PART-2)", Tech. Memorandum No.63/1, University Mathematical Laboratory, Cambridge University, Aug. 1963.


[CON66] L. Conway, B. Randell, D. Rozenberg, D. Senzig, "Dynamic Instruction Scheduling", IBM-ACS, February 23, 1966.


[ROZ66] D. Rozenberg, L. Conway, R. Riekert, "ACS Simulation Technique", IBM-ACS, Mar. 15, 1966.


[GAR67] H. Garfinkel, Studies in Ethnomethodology, Prentice Hall, Englewood Cliffs, N.J., June 1967.


[CON67-1]L. Conway, “MPM Timing Simulation”, ACS AP #67-115, August 25, 1967.


[CON67-1.1] L. Conway, “Timing Simulator Source Code Listings”, August 1967.


[CON67-1.2] L. Conway, “MPM Architecture and Simulator Notebook”, August 1967.


[CON67-2]L. Conway, "A Proposed ACS Logic Simulation System", IBM-ACS, October 31, 1967. 


[CON67-3] L. Conway, "ACS Logic Design Conventions: A Guide for the Novice", November 29, 1967. 


[IBM68] ACS-1 MPM Instruction Manual, Advanced Computing Systems, January 8, 1968.


[CON68] L. Conway, "The Computer Design Process: A Proposed Plan for ACS", IBM-ACS, August 6, 1968. 


[SCH71] H. Schorr, “Design Principles for a High-Performance System,” Proceedings of the Symposium on Computers and Automata, Polytechnic Institute of Brooklyn, April 13-15, 1971, pp. 165-192.


[HAS73] L. Hasbrouck, W. Madden, R. Rew, E. Sussenguth, and J. Wierzbicki, “Instruction execution unit,” U.S. Patent 3,718,912, February 1973.


[BRO75] F. P. Brooks, Jr., The Mythical Man-Month: Essays on Software Engineering, Addison-Wesley, 1975.


[CON79] L. Conway, The M.I.T.'78 VLSI System Design Course: A Guidebook for the Instructor of VLSI System Design, Xerox PARC, Aug. 12, 1979.  


[MEA80] C. Mead and L. Conway, Introductions to VLSI Systems, Addison-Wesley, 1980.


[CON80] L. Conway, A. Bell and M.E. Newell, “MPC79: The Large-Scale Demonstration of a New Way to Create Systems in Silicon”, Lambda, Second Quarter 1980.


[CON81] L. Conway, “The MPC Adventures: Experiences with the Generation of VLSI Design and

Implementation Methodologies”, Xerox PARC Tech. Report VLSI-81-2, Jan. 1981. Also in Microprocessing and Microprogramming, 10 (1982), pp. 209-228. 


[ALL81] F. Allen, “The history of language processor technology in IBM,” IBM Journal of Research and Development, Vol. 25, Issue 5, September 1981, pp. 535-548.


[MAR81] M. Marshall, L. Waller and H. Wolff, “The 1981 Achievement Award: For optimal VLSI design efforts, Mead and Conway have fused device fabrication and system-level architecture,” Electronics, Oct.20, 1981.


[DEL86] R. T DeLamarter, Big Blue: IBM's Use and Abuse of Power, Dodd, Mead and Co., 1986.


[COC88] J. Cocke, “The Search for Performance in Scientific Processors,” Turing Award Lecture, CACM, Vol. 31, No. 3, pp. 250-253, March 1988.


[WAT90] T. J. Watson, Jr., Father, Son & Co.: My Life at IBM and Beyond, Bantam [paperback], 1990, pp. 282-283; 315-316.


[CAR93] P. Carroll, Big Blues: The Unmaking of IBM, Crown Publishers, Inc., 1993.


[SMI95] J. E. Smith and G. S. Sohi, “The Microarchitecture of Superscalar Processors.,” Proceedings of the IEEE Vol. 83, No. 12, December 1995, pp.1609 - 1624.


[HEN96] J. L. Hennessy and D. A. Patterson, Computer Architecture: A Quantitative Approach, 2nd Ed., Morgan-Kaufman, 1996, Figure 4.60: Recent high-performance processors and their characteristics, p.359.


[HEN07] J. L. Hennessy and D. A. Patterson, Computer Architecture: A Quantitative Approach, 4nd Ed., Morgan-Kaufman, 2007; Chapter Two: Instruction-Level Parallelism and Its Exploitation, pp. 64-151.


[NRC99] Computer Science and Telecommunications Board, National Research Council, Funding a Revolution: Government Support for Computing Research, National Academy Press, 1999; Chapter 4, pp. 113-122.


[CON00] L. Conway, “IBM License to Make and Distribute Copies of Lynn Conway's ACS Archive”,, August 23, 2000.


[HIL00] M. A. Hiltzik, “Through the Gender Labyrinth: How a bright boy with a penchant for tinkering grew up to be one of the top women in her high-tech field”, Los Angeles Times Magazine, Cover story, Nov. 19, 2000.


[RAN05] B. Randell, “Reminiscences of Project Y and the ACS Project”, Technical Report Series CS-TR-891, School of Computing Science,University of Newcastle upon Tyne, February 2005.


[IEEE10] IEEE Computer Society, “Lynn Conway, 2009 Computer Pioneer Award Recipient,” January, 2010. 


[CHM10] Computer History Museum, Event: “IBM ACS System: A Pioneering Supercomputer Project of the 1960's”, February 18, 2010.


[EVA10] B. O. Evans, “The Ill Fated ACS Project”: pages 27-28 in Evans’ memoir The Genesis of the Mainframe, Wilhelm G. Spruth, ed., University of Leipzig, Department of computer science, June 2010.


[SMO10] M. Smotherman and D. Spicer, “Historical Reflections: IBM’s Single-Processor Supercomputer Efforts – Insights on the pioneering IBM Stretch and ACS projects”, Communications of the ACM, Vol. 53, No. 12, Dec. 2010, pp.28-30.


[ACO86] R. D. Acosta, J. Kjelstrup and H. C. Torng, “An Instuction Issuing Approach to Enhancing Performance in Multiple Functional Unit Processors”, IEEE Transactions of Computers, Vol. C-35, No. 9, September 1986, pp. 815-828.


[STE97] B. Steele, “CU professor is honored by Intel Corp. for his computer chip invention”, Cornell Chronicle, Dec. 11, 1997.


[USDC07] U.S. District Court for the Northern District of New York, Cornell University v Hewlett-Packard, Case 5:01-cv-01974-NAM-DEP, Summary Judgment, Jan. 31, 2007.


[STE08] B. Steele, “Cornell wins $184 million award from Hewlett-Packard for patent infringement”, Cornell Chronicle, June 6, 2008.


[DIC02] L. DiCarlo, “How Lou Gerstner Got IBM To Dance”, Forbes Magazine, November 11, 2002.


[ELL03] D. Ellenberg, “Book review -- Who Says Elephants Can't Dance?,”IBM developerWorks, May 15, 2003.


[ZUR68] F.W. Zurcher and B. Randell. “Iterative Multi-Level modelling: A methodology for computer system design,” Proc. IFIP Congress 68, Edinburgh, 1968, pp. D138-D142.


[WIR71] N. Wirth, “Program development by stepwise refinement”, CACM, Vol. 14, No. 4, April 1971, pp. 221-227.


[DIJ68] E. W. Dijkstra, “GOTO statement considered harmful”, CACM, Vol. 11, No. 3, May 1966, pp. 366-371.


[DAL72] O. J. Dahl, E. W. Dijkstra and C. A. R. Hoare, Structured Programming, Academic Press, 1972.


[AGE87] T. Agerwala and J. Cocke, “High Performance Reduced Instruction Set Processors," IBM Watson Research Center, RC 12434, 1987.


[SHR99] B. Shriver and P. Capek, “Just Curious: An Interview with John Cocke,” Computer Magazine, Vol. 32, No.11, November 1999, pp. 34-41.


[JOH90] M. Johnson, Superscalar Microprocessor Design, Prentice-Hall, 1990.


[SMO11]  M. Smotherman: File of DIS patent disclosures and correspondence, personal electronic communications, April-May, 2011.


[ASP00]  W. Aspray, Interviewer, Gene Amdahl Oral History, CHM Reference number: X5988.2011, Computer History Museum, September 24, 2000, p.26.


[THO67]  J. E. Thornton and S. R. Cray, “Simultaneous Multiprocessing Computer System”, U. S. Patent 3,346,851, October 10, 1967.


[MOSIS] MOSIS, “The MOSIS Service – More than 50,000 designs in over 25 years of operation”,


[SMO-STR] M. Smotherman, “IBM Stretch (7030) -- Aggressive Uniprocessor Parallelism”, historical reconstruction website, Clemson University.


[SMO-ACS] M. Smotherman, “IBM Advanced Computing Systems (ACS) -- 1961 – 1969”, historical reconstruction website, Clemson University.


[CON-ACS] L. Conway, Ed., “IBM-ACS Archive”,


[CON-VLSI] L. Conway, Ed., “The VLSI Archive: An online archive of documents and artifacts from the Mead-Conway VLSI design revolution”, 


[CON-web] L. Conway, Lynn Conway homepage,