Jack Dennis
Encyclopedia
Jack Dennis is a computer scientist
and retired MIT professor.
Dennis entered the Massachusetts Institute of Technology
(MIT) in 1949 as an electrical engineering major; he received his MS degree in 1954, and continued doctoral research and received his ScD in 1958. He became a full professor at MIT in 1969.
He was involved in early work on time-sharing
through the PDP-1
which his research group owned at MIT; that hardware later became famous in computer science
history as the machine on which hacker culture started. He also sponsored the MIT student-run Tech Model Railroad Club
in its early years, where the hacker culture is said to have taken root before spreading to the MIT Artificial Intelligence Lab.
Later, he was one of the founding members of the Multics
project, to which he contributed one of its most important concepts, the single-level memory. Multics, though not particularly commercially successful in itself, was an inspiration for Ken Thompson to develop Unix
.
The latter part of his career was devoted to non-von Neumann models of computation, architecture, and languages. He wanted to free programs from the concept of a program counter. So adopting the concept of "single-assignment," he along with his students and others developed data flow concepts which executed instructions as soon as data became available (this specific model came to be called "static" in contrast to Arvind's
later "dynamic").
He retired from MIT in 1987 to do independent projects and consulting. He developed the VAL static data-flow language which in turn inspired the compiler for the SISAL
programming language. Dennis was a visiting scientist at NASA
's Research Institute for Advanced Computer Science
(RIACS). In 1994 he was inducted as a Fellow
of the Association for Computing Machinery. He was elected to the National Academy of Engineering
in 2009.
Computer scientist
A computer scientist is a scientist who has acquired knowledge of computer science, the study of the theoretical foundations of information and computation and their application in computer systems....
and retired MIT professor.
Dennis entered the Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...
(MIT) in 1949 as an electrical engineering major; he received his MS degree in 1954, and continued doctoral research and received his ScD in 1958. He became a full professor at MIT in 1969.
He was involved in early work on time-sharing
Time-sharing
Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...
through the PDP-1
PDP-1
The PDP-1 was the first computer in Digital Equipment Corporation's PDP series and was first produced in 1960. It is famous for being the computer most important in the creation of hacker culture at MIT, BBN and elsewhere...
which his research group owned at MIT; that hardware later became famous in computer science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...
history as the machine on which hacker culture started. He also sponsored the MIT student-run Tech Model Railroad Club
Tech Model Railroad Club
The Tech Model Railroad Club is a student organization at the Massachusetts Institute of Technology , and one of the most celebrated model railroad clubs in the world, because of its historic role as a wellspring of hacker culture...
in its early years, where the hacker culture is said to have taken root before spreading to the MIT Artificial Intelligence Lab.
Later, he was one of the founding members of the Multics
Multics
Multics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
project, to which he contributed one of its most important concepts, the single-level memory. Multics, though not particularly commercially successful in itself, was an inspiration for Ken Thompson to develop Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
.
The latter part of his career was devoted to non-von Neumann models of computation, architecture, and languages. He wanted to free programs from the concept of a program counter. So adopting the concept of "single-assignment," he along with his students and others developed data flow concepts which executed instructions as soon as data became available (this specific model came to be called "static" in contrast to Arvind's
Arvind (computer scientist)
Arvind is the Johnson Professor of Computer Science and Engineering in the Computer Science and Artificial Intelligence Laboratory at the Massachusetts Institute of Technology...
later "dynamic").
He retired from MIT in 1987 to do independent projects and consulting. He developed the VAL static data-flow language which in turn inspired the compiler for the SISAL
SISAL
SISAL is a general-purpose single assignment functional programming language with strict semantics, implicit parallelism, and efficient array handling. SISAL outputs a dataflow graph in Intermediary Form 1...
programming language. Dennis was a visiting scientist at NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Research Institute for Advanced Computer Science
Research Institute for Advanced Computer Science
The was founded June 1, 1983 as a joint collaboration between the Universities Space Research Association and the NASA Ames Research Center...
(RIACS). In 1994 he was inducted as a Fellow
Fellow
A fellow in the broadest sense is someone who is an equal or a comrade. The term fellow is also used to describe a person, particularly by those in the upper social classes. It is most often used in an academic context: a fellow is often part of an elite group of learned people who are awarded...
of the Association for Computing Machinery. He was elected to the National Academy of Engineering
National Academy of Engineering
The National Academy of Engineering is a government-created non-profit institution in the United States, that was founded in 1964 under the same congressional act that led to the founding of the National Academy of Sciences...
in 2009.
External links
- Jack B. Dennis home page
- Photograph of Jack B. Dennis
- Oral history interview with Jack B. Dennis at the Charles Babbage InstituteCharles Babbage InstituteThe Charles Babbage Institute is a research center at the University of Minnesota specializing in the history of information technology, particularly the history since 1935 of digital computing, programming/software, and computer networking....
, University of Minnesota. Dennis describes his educational background and work in time-sharing computer systems at the Massachusetts Institute of Technology (MIT), including the TX-0TX-0The TX-0, for Transistorized Experimental computer zero, but affectionately referred to as tixo , was an early fully transistorized computer and contained a then-huge 64K of 18-bit words of magnetic core memory. The TX-0 was built in 1955 and went online in 1956 and was used continually through the...
computer, the work of John McCarthyJohn McCarthy (computer scientist)John McCarthy was an American computer scientist and cognitive scientist. He coined the term "artificial intelligence" , invented the Lisp programming language and was highly influential in the early development of AI.McCarthy also influenced other areas of computing such as time sharing systems...
on time-sharing, and the influence of the Information Processing Techniques Office of the Advanced Research Projects Agency. Dennis also recalls the competition between Digital Equipment CorporationDigital Equipment CorporationDigital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
, General ElectricGeneral ElectricGeneral Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
, Burroughs, and International Business Machines, to manufacture time-sharing systems. He describes the development of MULTICSMulticsMultics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
at General Electric. - Parallel Computing Pioneers — Jack B. Dennis
