Richard D. Greenblatt (born December 25, 1944) is an American
computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...
programmer
A programmer, computer programmer or coder is an author of computer source code someone with skill in computer programming.
The professional titles Software development, ''software developer'' and Software engineering, ''software engineer' ...
. Along with
Bill Gosper, he may be considered to have founded the
hacker
A hacker is a person skilled in information technology who achieves goals and solves problems by non-standard means. The term has become associated in popular culture with a security hackersomeone with knowledge of bug (computing), bugs or exp ...
community,
and holds a place of distinction in the
communities
A community is a Level of analysis, social unit (a group of people) with a shared socially-significant characteristic, such as place (geography), place, set of Norm (social), norms, culture, religion, values, Convention (norm), customs, or Ide ...
of the programming language
Lisp
Lisp (historically LISP, an abbreviation of "list processing") is a family of programming languages with a long history and a distinctive, fully parenthesized Polish notation#Explanation, prefix notation.
Originally specified in the late 1950s, ...
and of the
Massachusetts Institute of Technology
The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...
(MIT)
Artificial Intelligence Laboratory.
Early life
Greenblatt was born in Portland, Oregon on December 25, 1944. His family moved to Philadelphia, Pennsylvania when he was a child. He later moved to Columbia, Missouri with his mother and sister when his parents divorced.
Career
Becoming a hacker
Greenblatt enrolled in
MIT
The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...
in the fall of 1962, and around his second term as an undergraduate student, he found his way to MIT's famous
Tech Model Railroad Club. At that time,
Peter Samson had written a program in
Fortran for the
IBM 709
The IBM 709 is a computer system that was announced by IBM in January 1957 and first installed during August 1958. The 709 was an improved version of its predecessor, the IBM 704, and was the third of the IBM 700/7000 series of scientific compute ...
series machines, to automate the tedious business of writing the intricate timetables for the Railroad Club's vast model train layout. Greenblatt felt compelled to implement a Fortran
compiler
In computing, a compiler is a computer program that Translator (computing), translates computer code written in one programming language (the ''source'' language) into another language (the ''target'' language). The name "compiler" is primaril ...
for the
PDP-1
The PDP-1 (Programmed Data Processor-1) is the first computer in Digital Equipment Corporation's PDP series and was first produced in 1959. It is known for being the most important computer in the creation of hacker culture at the Massachusetts ...
, which then lacked one. There was no computer time available to
debug
In engineering, debugging is the process of finding the root cause, workarounds, and possible fixes for bugs.
For software, debugging tactics can involve interactive debugging, control flow analysis, log file analysis, monitoring at the ap ...
the compiler, or even to type it into the computer. Years later, elements of this compiler (combined with some ideas from fellow TMRC member Steven Piner, the author of a very early
PDP-4
The PDP-4 was the successor to the Digital Equipment Corporation's PDP-1.
History
This 18-bit machine, first shipped in 1962, was a compromise: "with slower memory and different packaging" than the PDP-1, but priced at $65,000 - less than half t ...
Fortran compiler while working for
Digital Equipment Corporation
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president until ...
) were typed in and "showed signs of life". However, the perceived need for a Fortran compiler had evaporated by then, so the compiler was not pursued further. This and other experiences at TMRC, especially the influence of
Alan Kotok, who worked at DEC and was the junior partner of the design team for the
PDP-6
The PDP-6, short for Programmed Data Processor model 6, is a computer developed by Digital Equipment Corporation (DEC) during 1963 and first delivered in the summer of 1964. It was an expansion of DEC's existing 18-bit systems to use a 36-bit da ...
computer, led Greenblatt to the
AI Lab, where he proceeded to become a "hacker's hacker" noted for his programming acumen as described in
Steven Levy
Steven Levy (born 1951) is an American journalist and editor at large for '' Wired'' who has written extensively for publications on computers, technology, cryptography, the internet, cybersecurity, and privacy. He is the author of the 1984 boo ...
's ''
Hackers: Heroes of the Computer Revolution'', and as acknowledged by
Gerald Jay Sussman and
Harold Abelson when they said they were fortunate to have been apprentice programmers at the feet of
Bill Gosper and Richard Greenblatt.
Indeed, he spent so much time programming the
Programmed Data Processor
Programmed Data Processor (PDP), referred to by some customers, media and authors as "Programmable Data Processor," is a term used by the Digital Equipment Corporation from 1957 to 1990 for several lines of minicomputers.
The name "PDP" i ...
(PDP) machines there that he failed out of MIT as a first-term junior and had to take a job at a firm, Charles Adams Associates, until the AI Lab hired him about 6 months later.
Lisp Machines, Inc.
In 1979, he and
Tom Knight were the main designers of the MIT
Lisp machine. He founded
Lisp Machines
Lisp Machines, Inc. was a company formed in 1979 by Richard Greenblatt of MIT's Artificial Intelligence Laboratory to build Lisp machines. It was based in Cambridge, Massachusetts.
By 1979, the Lisp Machine Project at MIT, originated and he ...
, Inc. (later renamed Gigamos Systems), according to his vision of an ideal hacker-friendly computer company, as opposed to the more commercial ideals of
Symbolics
Symbolics, Inc., is a privately held American computer software maker that acquired the assets of the former manufacturing company of the identical name and continues to sell and maintain the Open Genera Lisp (programming language), Lisp sy ...
.
Significant software developed
He was the main implementor of
Maclisp
Maclisp (or MACLISP, sometimes styled MacLisp or MacLISP) is a programming language, a dialect of the language Lisp. It originated at the Massachusetts Institute of Technology's (MIT) Project MAC (from which it derived its prefix) in the late 19 ...
on the
PDP-6
The PDP-6, short for Programmed Data Processor model 6, is a computer developed by Digital Equipment Corporation (DEC) during 1963 and first delivered in the summer of 1964. It was an expansion of DEC's existing 18-bit systems to use a 36-bit da ...
. He wrote
Mac Hack, the first computer program to play tournament-level chess and the first to compete in a human chess tournament. AI skeptic
Hubert Dreyfus
Hubert Lederer Dreyfus ( ; October 15, 1929 – April 22, 2017) was an American philosopher and a professor of philosophy at the University of California, Berkeley. His main interests included phenomenology, existentialism and the philosophy of ...
, who famously made the claim that computers would not be able to play high-quality chess, was beaten by the program, marking the start of "respectable"
computer chess
Computer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysi ...
performances. In 1977, unbeaten chess champion
Bobby Fischer
Robert James Fischer (March 9, 1943January 17, 2008) was an American Grandmaster (chess), chess grandmaster and the eleventh World Chess Championship, World Chess Champion. A chess prodigy, he won his first of a record eight US Chess Champi ...
played three games in
Cambridge, Massachusetts
Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...
against Greenblatt's computer program, and Fischer won all of them.
Greenblatt, along with
Tom Knight and
Stewart Nelson, co-wrote the
Incompatible Timesharing System
Incompatible Timesharing System (ITS) is a time-sharing operating system developed principally by the MIT Artificial Intelligence Laboratory, with help from Project MAC. The name is the jocular complement of the MIT Compatible Time-Sharing Syste ...
(ITS), a highly influential
time-sharing
In computing, time-sharing is the Concurrency (computer science), concurrent sharing of a computing resource among many tasks or users by giving each Process (computing), task or User (computing), user a small slice of CPU time, processing time. ...
operating system for the
PDP-6
The PDP-6, short for Programmed Data Processor model 6, is a computer developed by Digital Equipment Corporation (DEC) during 1963 and first delivered in the summer of 1964. It was an expansion of DEC's existing 18-bit systems to use a 36-bit da ...
and
PDP-10
Digital Equipment Corporation (DEC)'s PDP-10, later marketed as the DECsystem-10, is a mainframe computer family manufactured beginning in 1966 and discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especi ...
used at
MIT
The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...
.
References
External links
A speechby
Richard Stallman
Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...
in which he gives some background about Greenblatt
{{DEFAULTSORT:Greenblatt, Richard
1944 births
Living people
Lisp (programming language) people
People from Portland, Oregon
Massachusetts Institute of Technology alumni
American computer businesspeople
American artificial intelligence researchers
Hackers