Early Life and Interest in Computing:
John Hennessey was born in New York City but grew up on Long Island. His father worked in the aerospace industry, sparking his early interest in computing. In high school, he and a friend built a tic-tac-toe machine out of surplus relays, demonstrating his passion for building and programming.

Educational Background and Research Experience:
Hennessey pursued an undergraduate degree in electrical engineering at Villanova University. He had a strong interest in computing, which was further ignited by his first programming course and participation in an advanced section due to his prior Fortran programming experience. During his undergraduate years, he worked on a research project involving a self-microprogrammed machine, deepening his fascination with computer science.

Decision to Pursue Graduate Studies in Computer Science:
Hennessey’s undergraduate research experience and growing interest in computer science led him to pursue graduate work in the field. He completed his undergraduate degree in three and a half years and moved to Stony Brook University for his graduate studies.

Personal Life:
During his undergraduate years at Villanova, he met his future wife, who has been his partner for over 30 years.

High School Sweetheart Turned Wife:
John Hennessey and his wife met in senior year of high school and later reunited after college, eventually marrying in 1974.

Thesis Work at Stony Brook:
Hennessey’s thesis focused on real-time programming, specifically developing a language and compiler technology to control a finely controlled x-ray scanning device for bone density measurements.

Stanford Recruitment:
Hennessey interviewed at 14 universities before accepting an offer from Stanford University. He was drawn to Stanford’s strong computer science department and the opportunity to work with renowned researchers like Mike Flynn, Ed McCluskey, and Don Knuth.

Early Research Areas:
Hennessey continued his work in language design and compiler technology. He got involved in the S1 project at Lawrence Livermore, working on compiler technology for high-performance computing. Hennessey collaborated with Fred Chow on register allocation and developed the U-code concept, experimenting with single optimization components and intermediate formats. He explored language extensions to make Pascal more practical for systems programming, competing with C.

Geometry Engine Project:
Hennessey contributed to the Geometry Engine project, led by Jim Clark, by creating a programming language called SLIM and a system for writing microcode. This project sparked his interest in VLSI technology and exploiting it in hardware design.

VLSI and Silicon Compilers:
Hennessey presented his work on VLSI at a Caltech conference, catching the attention of Carver Mead. He began consulting for Silicon Compilers, a company developing tools for chip generation. Hennessey collaborated with Dave Cutler and others on the MicroVAX-1 chipset design at DEC.

Inspiration from the MicroVAX 1:
John Hennessey’s experience working on the MicroVAX 1 project sparked insights about the efficiency of using a compiler to eliminate the interpretation overhead of micro-coded engines.

MIPS Project Initiation:
MIPS (Microprocessor without Interlocked Pipeline Stages) project was conceptualized as a brainstorming class at Stanford University. The goal was to explore the potential of single-chip processors and leverage compiler technology to optimize performance.

Key Design Decisions:
MIPS architecture was designed with a focus on register-register operations and a significant number of general-purpose registers to enhance compiler efficiency. The project aimed to simplify the instruction set and eliminate unnecessary interpretation steps, unlike the prevailing trend of adding more instructions.

MIPS Team Members and Contributions:
The MIPS team consisted of dedicated students who later went on to make significant contributions in the field of computer architecture. Thomas Gross optimized pipeline scheduling, Chris Rowan co-founded Tensilica, Norm Juppe continued research at HP Labs and DECWRL, and Steve Przybylski became an independent consultant. Anant Agarwal and Forrest Baskin also played crucial roles in the project’s success.

Challenges and Advantages of Small University Projects:
Small university projects faced challenges due to limited resources compared to large corporations. However, they had the advantage of being able to take risks and explore unconventional ideas without being bound by industry constraints.

Collaboration with Berkeley and the RISC Movement:
Stanford interacted with the University of California, Berkeley, where Dave Patterson was conducting research on Reduced Instruction Set Computers (RISC). Both teams believed in the benefits of simplicity and compiler optimization for improving performance.

DARPA’s Role in Fostering Research:
DARPA provided funding and encouragement for the early VLSI work and subsequent MIPS project. DARPA’s focus on enabling out-of-the-box thinking and experimentation was crucial in driving innovation.

Decline of Industrial R&D and the Shift to Universities:
The decline of industrial research centers like Bell Labs, Xerox PARC, and IBM research has led to universities playing a more significant role in fundamental research. These centers once provided substantial resources and freedom for researchers, but their focus has shifted toward short-term results.

The Importance of Public Goods in Technological Advancements:
Many groundbreaking inventions in industry, such as Unix, the personal computer, and IBM’s computing technologies, have become public goods. Universities are well-suited to pursue research that leads to public goods due to their long-term perspective and commitment to fundamental knowledge creation.

John Hennessey’s Industry Connections:
Hennessey’s early industry connections stemmed from Stanford’s emphasis on collaboration between academia and industry. His involvement with Silicon Graphics and MIPS Technologies allowed him to apply research findings to practical applications.

Experience Matters:
John Hennessey believes that faculty members benefit from engaging in consulting or other roles that expose them to industry practices. Real-world experience helps professors better understand how to apply theoretical principles and enhances their teaching.

MIPS’ Humble Beginnings:
Hennessey’s involvement with Silicon Compilers and Silicon Graphics led to the creation of MIPS. The initial goal was to make the technology accessible to industry, but they underestimated the challenges of commercialization. John Masuris, a co-founder of MIPS, joined Hennessey in the effort to bring the technology to market.

Gordon Bell’s Encouragement:
Gordon Bell, a prominent figure in the industry, urged Hennessey and his team to start a company to commercialize their technology. Bell believed that the technology had the potential to revolutionize the industry but would remain untapped if not actively pursued.

Venture Capital and a Naive Business Plan:
Hennessey and his team approached venture capitalists with a business plan that lacked market analysis and financial projections. They believed the revolutionary nature of their technology would be enough to secure funding. Mayfield, a venture capital firm that had previously funded Silicon Graphics, agreed to fund MIPS despite the shortcomings of the business plan.

Hennessey’s Leave of Absence:
Hennessey decided to take a leave of absence from Stanford to focus on MIPS but intended to return eventually. Investors were concerned about the lack of a CEO and management team among the founders.

Computer Systems Lab:
Hennessey ran the computer systems lab before starting MIPS.

Inspiration:
Mike Flynn and Ed McCluskey recognized the need for a bridge between electrical engineering and computer science at Stanford. The Digital Systems Lab, later renamed the Computer Systems Lab, became the home for experimental computer engineering and software research.

Early Members and Leadership:
Forrest Baskett, Vint Cerf, and John Hennessey were among the early members of the lab. Hennessey eventually took over as head of the lab after receiving tenure.

Interdisciplinary Culture:
The lab helped foster a collaborative culture, producing graduates who were proficient in both electrical engineering and computer science.

Bringing in Steve Blank:
MIPS sought to expand its marketing expertise and brought in Steve Blank, who had a wealth of ideas and marketing experience. Blank led the company’s marketing and sales efforts, including cold calls to potential customers.

Team Building:
Hennessey emphasized the importance of hiring great people from the beginning. Chris Rowan and Steve Przybylski joined the VLSI team. Larry Weber and John Mashey were hired to lead the compiler and OS teams, respectively.

Challenging Conventional Wisdom:
MIPS team members were willing to rethink conventional wisdom in both hardware and software. Mashey had previously considered a RISC-type chip proposal from Dave Ditzel at Bell Labs.

Shared Experience:
Patterson, Hennessey, John Cocke, and others had prior experience with CISC machines, leading them to believe that a simpler RISC approach was the way to go.

Founding of MIPS Technologies:
MIPS Technologies was founded in 1984 by John Hennessey and John Mashey. The company aimed to develop and commercialize the MIPS architecture, a reduced instruction set computer (RISC) architecture. Prime Computer, facing challenges with its hardware, expressed interest in a new board for their computers, leading to an early partnership with MIPS Technologies.

Challenges and Milestones:
The initial project faced a tight schedule for designing software, chips, and other components. MIPS Technologies redesigned the MIPS architecture, implemented the chip, and developed an operating system. The team managed to deliver an engineering sample unit to Prime Computer by the end of 1985, showcasing the dedication and capabilities of a smaller, dedicated team.

Management and Team Building:
MIPS Technologies faced challenges in building out its management team, particularly in terms of CEO, sales, and marketing leadership. The company struggled to find the right team members and develop effective strategies for scaling the business.

Business Model and Product Development:
To demonstrate and deliver MIPS technology, MIPS Technologies realized the need to build an engineering team capable of creating an entire computer system. The company faced challenges in structuring a business model that could support the size of the engineering team required for product development.

Interactions Between Compilers and Operating Systems:
The team recognized the importance of optimizing compilers and their interactions with C and operating systems. Compilers became more sophisticated and aggressive in reordering code, impacting instruction sequences and requiring careful consideration during development.

Early Machine Shipments and Research Directions:
By mid-1986, MIPS Technologies had shipped early machines, encountering various surprises and challenges. Hennessey returned to Stanford, consulting part-time and running the Computer Systems Laboratory (CSL). Research focus shifted toward addressing issues with floating point, virtual memory, and parallelism in the MIPS architecture. The team began exploring multiprocessors as a cost-effective way to build powerful machines, leading to brainstorming and projects at Stanford.

Scalability and Cache Coherency:
Conventional wisdom suggested that scalability required sacrificing cache coherency, making memory placement visible to programmers. Machines like IBM’s RP3 and Carnegie Mellon’s CM star faced programming challenges due to this approach.

Divergence of Message Passing and Cache Coherent Models:
In the 1980s, there was a growing consensus that scalable parallel machines required message passing. John Hennessey and his colleagues believed that a shared memory cache coherent model could still be viable. They were concerned that a split between message passing and cache coherency would fragment the parallel processing market and hinder software development.

Development of the DASH Machine:
Hennessey and his team at Stanford University designed and built the DASH machine, a shared memory cache coherent parallel computer. The DASH machine used a distributed memory model with a directory-like structure to maintain coherency. It was implemented using small-scale multiprocessor boards from SGI machines.

Impact on SGI’s Work:
The DASH project influenced SGI’s later work on parallel machines. Dan Lenowski and Jim Loudon, key members of the DASH team, joined SGI and contributed to the development of the Origin series of machines. The Origin series improved upon the implementation of the DASH machine and became a successful commercial product.

Challenges in Designing the Flash Machine:
Hennessey and his team at Stanford embarked on the Flash project, aiming to build a second-generation parallel machine. The initial concept involved a communications processor capable of both shared memory and message passing. Intel’s withdrawal from the high-end computing business forced them to switch to LSI Logic’s gate array technology. The redesign caused delays and required significant re-engineering of the project.

Software Challenges in Parallel Processing:
The Flash project highlighted the importance of software development for parallel systems. Mendel Rosenblum’s SimOS work helped understand the interaction between the operating system and the hardware architecture, leading to the development of VMware technology. Research efforts focused on understanding parallel program behavior and characterizing properties such as locality and sharing patterns.

MIPS R4000: Transition to 64-bit Architecture:
Hennessey played a role in the decision to make the MIPS R4000 a 64-bit processor. The motivation was to anticipate the need for larger address space and the increasing demand for data movement in applications like gaming and graphics. The 64-bit design also attracted interest from companies like Nintendo and Cisco Systems.

ECL Technology and the MIPS Acquisition by SGI:
MIPS acquired a company with a new bipolar technology called ECL, aiming to improve processor performance. Dependence on a single supplier and challenges with the technology led to delays and distractions. The ECL technology was eventually abandoned, and MIPS shifted its focus to CMOS technology. MIPS faced difficulties in the system business, leading to its acquisition by Silicon Graphics.

MIPS’s Business Model Challenges and Semiconductor Partnerships:
MIPS faced challenges in establishing a viable business model, particularly in the workstation and server domains. Semiconductor partners were crucial for MIPS’s success, providing access to world-class technology and expanding sales reach. Motorola nearly became a semiconductor partner but ultimately opted for a short-term, less painful route, despite recognizing MIPS’s long-term potential. The debate over proprietary systems versus open architecture persisted, with companies clinging to proprietary solutions to protect gross margins.

John Hennessey’s Tenure as Department Head of Computer Science at Stanford:
Hennessey became department head in 1993-1994, overseeing the move to the Gates Computer Science building. The department was scattered across multiple buildings, and the new space provided an opportunity for increased cross-communication and collaboration. Hennessey facilitated more interaction between graphics and vision, as well as between theory and systems researchers.

John Hennessey’s Administrative Roles and Skills:
Hennessey transitioned from department chair to dean and eventually to president of Stanford. Administrative roles require strong people skills, patience, and the ability to celebrate the successes of others. Hennessey emphasized the importance of enjoying the successes of students, faculty, and researchers that one has helped enable.

John Hennessey’s Continued Involvement in Research and PhD Supervision:
Hennessey continued to supervise PhD students while serving as department chair and dean. He scaled back his PhD supervision slightly upon becoming dean but maintained a large group of students.

Challenges with Existing Textbooks:
Graduate-level computer architecture courses often relied on collections of papers with inconsistent terminology, making it difficult for instructors to stitch together a cohesive curriculum.

Motivation for a Quantitative Approach:
Hennessey and Patterson were dissatisfied with existing textbooks that merely summarized various papers.

Focus on Methodology:
They believed that the methodology for thinking about computer architecture, including quantitative analysis and performance measurement, was more important in the long term than specific architectural insights.

Quantitative Approach:
The book aimed to present computer architecture as a quantitative science, emphasizing performance analysis and measurement.

CPU Performance Equation:
The CPU performance equation, which had gained traction in the research world, served as a cornerstone for understanding core CPU performance.

Extension to Other Areas:
The quantitative approach could be applied to other areas of computer architecture, such as cache systems and I/O systems, despite the challenges in quantifying I/O performance.

Goal of the Book:
Hennessey and Patterson set out to write a book that provided a structured and quantitative approach to computer architecture, focusing on engineering principles and performance analysis.

Book Writing Initiation:
John Hennessey and David Patterson took a break from their university roles to focus on writing a groundbreaking book on computer architecture. They found a home at DEC World, a research lab in Palo Alto, where they could collaborate and receive feedback.

Setting High Standards:
Hennessey and Patterson aimed to create an exceptional book that would push the boundaries of computer architecture education. They established a collaborative working relationship that allowed them to challenge and motivate each other to produce high-quality content.

Involving Reviewers and Instructors:
The authors engaged a team of expert reviewers who provided constructive criticism and valuable suggestions. They actively listened to the reviewers’ comments and made significant improvements to the book’s content and structure.

Iterative Development Process:
The book underwent multiple stages of development, starting with a collection of notes used in Stanford and Berkeley classes. They progressed through alpha and beta versions, involving instructors and students in the feedback process. This iterative approach allowed for continuous refinement and improvement of the book’s content.

Publisher Selection and Collaboration:
Hennessey and Patterson sought a publisher that would provide creative freedom, support, and connections within the computer architecture community. They found the ideal partner in Morgan Kaufman, who agreed to accommodate their unique requirements, including a streamlined chapter pipelining process.

Timely Publication and Staying Current:
The authors recognized the importance of timely publication in a rapidly evolving field like computer architecture. They worked efficiently to minimize the time between writing and publication, ensuring that the book contained the most up-to-date information. Morgan Kaufman’s willingness to adapt their processes to the authors’ needs was crucial in achieving this goal.

Textbook Dominance:
John Mashey highlights the remarkable success of a textbook that rapidly became the standard in its field. This book’s widespread adoption showcases its exceptional quality and impact on education.

Transition to Dean of Engineering:
John Hennessey became the Dean of Engineering at Stanford in 1996. He reflects on the significant change in responsibilities compared to his previous role as department chair.

Motivation for Accepting the Deanship:
Hennessey’s decision to become Dean of Engineering was driven by the challenges faced by the computer science department, which extended beyond departmental boundaries. He saw an opportunity to address issues such as faculty compensation, housing, and interdisciplinary collaborations.

Condi Rice’s Involvement:
Condi Rice, then Provost at Stanford, played a crucial role in Hennessey’s final interview for the Dean of Engineering position. Her involvement underscores the importance of the decision and the high regard in which Hennessey was held.

Challenges and Changes in Engineering at Stanford:
During Hennessey’s tenure as Dean, the engineering school at Stanford experienced significant changes. The strongest departments continued to flourish, but other disciplines underwent key transformations.

Biomedical Sciences and Bioengineering:
A major focus for Hennessey was the development of bioengineering and the integration of biomedical sciences into the engineering school. He recognized the need for collaboration between engineering and the medical school to foster innovation in this field.

Collaboration with the Medical School:
At the time, Stanford had several collaborations with the medical school, but these were fragmented across various departments. Hennessey sought to create a more cohesive and comprehensive approach to biomedical research and education.

Expansion into the Biotech Sector:
Hennessey recognized the potential for growth in the biotech sector, which was primarily associated with chemical engineering. He made strategic hires in this area to strengthen Stanford’s position in the field.

Exploring a Joint Department:
In collaboration with the Dean of the Medical School, Hennessey explored the possibility of creating a joint department dedicated to biomedical sciences. This initiative aimed to foster closer ties between engineering and medicine and promote interdisciplinary research and education.

Engineering’s Translational Role:
Engineering takes basic science insights and applies them to practical problems. At Stanford, a new department was needed to bridge the gap between clinical and basic science departments in medicine.

Bioengineering Department:
Stanford’s bioengineering department is unique in being jointly located between the medical and engineering schools. This structure was essential for effective collaboration and the department’s success.

Civil Engineering’s Transformation:
Civil engineering at Stanford shifted its focus towards environmental issues. This change reflected the department’s commitment to addressing contemporary challenges.

Fostering Cooperation:
Building a bridge between medicine and engineering was crucial for Stanford’s success. Despite commonalities in goals, differences in work styles and funding structures existed. Engineering’s emphasis on education contrasted with medicine’s focus on patient care.

Background:
John Hennessey, former Dean of Engineering at Stanford University, believed that biology would be the transformational science of the 21st century. He saw opportunities for progress in interdisciplinary collaborations, particularly between biology and other fields like engineering, physics, and chemistry.

BioX Concept:
Hennessey and a group of faculty from across the university came together to develop the concept of BioX, a center for interdisciplinary research and collaboration in the biosciences. The goal was to create a nucleus that would bring together researchers from different disciplines to work on common problems.

Location and Architecture:
BioX was strategically located at the intersection of computer science, the medical school, and electrical engineering. The building was designed by architect Norman Foster to be a meeting place and a symbol of the collaborative spirit of BioX.

Success and Impact:
BioX became a successful incubator for interdisciplinary research and collaboration, leading to the establishment of the new bioengineering department at Stanford. It attracted renowned faculty members and fostered a vibrant community of researchers.

Conclusion:
Hennessey’s vision for interdisciplinary collaboration in the biosciences has had a lasting impact on Stanford University and beyond. BioX continues to be a hub for groundbreaking research and a model for successful interdisciplinary collaboration.

Challenges of Being Provost and President at Stanford:
As provost, John Hennessey faced the challenge of overseeing a large and diverse university with faculty from a wide range of disciplines. He had to make difficult decisions about resource allocation and academic priorities. As president, he faced additional demands on his time and travel schedule and had to balance the needs of various constituencies.

Contemplating the Presidency:
John Hennessey initially hesitated to accept the position of president, as it would mean leaving his familiar role as provost and taking on even greater responsibilities. However, he was persuaded by the opportunity to shape the direction of Stanford University and address pressing global challenges.

Stanford’s Role in Innovation and Addressing Global Challenges:
John Hennessey emphasized the growing importance of universities as sources of innovation and breakthrough thinking. He identified environmental challenges, energy and global warming, threats to peace, and economic disparities as some of the pressing issues that Stanford should address. He believed that the university’s strengths in research and education could contribute to finding solutions to these problems.

Industry Collaborations for Energy and Environment:
During his tenure as president, John Hennessey initiated several collaborations between Stanford University and industry partners to address energy and environmental challenges. He recognized the need for universities to engage with industry to translate research findings into practical solutions.

Early Career and Influences:
John Hennessey’s academic career began at Stanford University, where he was guided by mentors such as Mike Flynn and Forrest Baskett. His early research focused on building experimental research teams and pursuing experimental computer science and computer engineering projects.

MIPS and Entrepreneurial Experience:
Hennessey co-founded MIPS Computer Systems, driven by the need to bring technology out into the world. This entrepreneurial experience taught him the importance of making quick decisions, dealing with complex personalities, and understanding the pressure of time constraints.

Transition to University Leadership:
Hennessey became the Dean of Engineering at Stanford University and later the President of Stanford University. He recognized the need for universities to address global problems collaboratively and interdisciplinarily. Under his leadership, Stanford focused on environmental and international issues, securing funding for research projects like the Global Climate and Energy Project (GCEP).

Advice and Reflections:
Hennessey emphasizes the importance of taking risks, being bold, and recruiting the best people to work with. He believes that technology alone does not guarantee success and appreciates the role of students as magnifiers of impact. Hennessey acknowledges the challenges of leading a university but values the opportunity to facilitate the accomplishments of others. He advises students to be unafraid of taking risks and to work with great people to create new things. Hennessey expresses his appreciation for being in the computing field, which he sees as constantly reinventing itself and having a profound impact on the world.