• Edgar G. Daylight. From Mathematical Logic to Programming-Language Semantics — a Discussion with Tony Hoare. Journal of Logic and Computation (to appear).
  

  Section 2.3 covers Hoare’s Algol work at Elliot.

• Edgar G. Daylight. Pluralism in Software Engineering: Turing Award Winner Peter Naur Explains. CONVERSATIONS. Issue 1, Volume 2011, Lonely Scholar, 2011.
  

  Part I of this wide-ranging interview covers Naur’s work on Algol 60, including the DASK and GIER implementations. He also makes a few remarks about Algol 68.

• Pierre Mounier-Kuhn. From universal project to sunken culture : Algol in France. SHOT / SIGCIS Workshop 2011, Cultures and Communities in the History of Computing, Cleveland (OH), 6th November 2011. PDF

• Edgar G. Daylight. Dijkstra’s Rallying Cry for Generalization: The Advent of the Recursive Procedure, Late 1950s–Early 1960s.
  • The Computer Journal, Advance access, March 8, 2011. Oxford Journals
  • Peer-reviewed and edited preprint at dijkstrascry.com. HTML PDF

In a section on Future Work near the end of the paper, Daylight notes, “Research contributions of Gödel, Carnap, Turing and Tarski have been studied and documented over and over again by logicians and philosophers themselves. Computer scientists, by contrast, have yet to commence with similar work concerning the ideas of their fathers: Dijkstra, McCarthy, Hoare and others. This, in turn, explains my motivation to write this paper.” Daylight, who is a post-doctorate researcher in the history of computing, has set up the blog-style web site Dijkstra’s Rallying Cry for Generalization as a way to report on his ongoing research into Dijkstra’s writings, including the E. W. Dijkstra Archive at the University of Texas and additional materials Dijkstra’s family donated. Daylight is off to a good start. He welcomes suggestions for improving his blog, and notes he’ll be adding photographs of Dijkstra soon.

In that spirit, I offer the following photograph, taken at the 1973 Marktoberdorf Summer School, of instructor Dijkstra and student McJones. Dijkstra’s subsequent trip report (EWD385) mentions my friend Dave Redell (who took the photograph) and me because we served as “intelligent terminals” in an “interactive programming session”.

It was only recently, Bell notes, that “Software was finally added to list of things collected, such as the history of FORTRAN including original source code.” The FORTRAN collection to which Gordon refers is here; a catalog search of FORTRAN-related items in the museum’s archives is available here.

Bell gives a list of some two dozen “Mona Lisas” in the collection, all hardware artifacts. He concludes this section by saying “Regrettably, I omit that hard to see, hard to describe, essential software from COBOL, FORTRAN, and LISP, various Operating Systems, and on through Visicalc, and the Relational database.” I strongly agree with Bell about the importance of collecting and displaying such historic software. I’m glad to be able to point the previously-mentioned FORTRAN collection, and to similar collections for LISP, ALGOL, and C++. Others have assembled extensive collections on, for example, the Multics and Unix operating systems, PDP-10 systems and applications, and many more. Two of the earliest relational database management systems, Berkeley Ingres and IBM System R, have been preserved but are not yet easily accessible. For the most part, these collections are aimed at a more scholarly audience; I hope they will serve as source materials for future exhibits for a wider audience.

Thanks again to the many people down through the years who have patiently answered my questions, supplied copies of source code and documents, and allowed me to post copies.

For a number of years Bob has been involved in volunteer activities at the Computer History Museum, and recently he organized his thoughts on how museums can use the web to present technology, in the form of this article: “Museums in the Computer Age: meeting the challenge of technology“. Bob invites comments on the article via email at bobpatrick@mac.com.

Stoyan has been involved with Lisp for four decades. In the early 1970s he implemented Lisp using only Berkeley and Bobrow as a reference, and this system became the basis for all artificial intelligence work in his native East Germany. In the late 1970s he became interested in the history of Lisp, and published the book LISP – Anwendungsgebiete, Grundbegriffe, Geschichte (Akademie-Verlag, Berlin, 1980) about Lisp and its history. In 1981 he emigrated to West Germany and began a career as a university professor; by 1990 he became Professor of Artificial Intelligence of the Friedrich-Alexander-Universität Erlangen-Nürnberg. He also wrote the two-volume Programmiermethoden der Künstlichen Intelligenz (Springer, 1988) about artificial intelligence programming. (For more details, see his speaker biography from the 2007 International Lisp Conference.)

In addition to his first book, Stoyan has published a number of papers on the early history of Lisp, including:

• LISP History. LISP Bulletin #3, December 1979, pages 44-55. PDF at www.artinfo-musinfo.org and ACM Digital Library
• Early LISP history (1956-1959). A version was published in: Proceedings of the 1984 ACM Symposium on LISP and functional programming, Austin, Texas, pages 299-310. ACM Digital Library
• The Influence of the Designer on the Design – J. McCarthy and Lisp. Originally published in: V. Lifschitz, editor. Artificial Intelligence and Mathematical Theory of Computation: Papers in Honor of John McCarthy. Academic Press Professional, Inc., 1991.
• Lisp: Themes and History. Invited Lecture at International Lisp Conference 2007. MP3 at CHM

The Herbert Stoyan Collection on LISP Programming (Lot X5687.2010) is quite large (94.5 linear feet in 87 boxes), and the Museum is currently in the throws of construction for the major new exhibit Revolution: The First 2000 Years of Computing. But through the combined efforts of staff and volunteers, the collection will be organized and made accessible, with portions scanned and available online. To get a taste of the depth and breadth of the collection, see Stoyan’s LISP Bibliography and searchable LISP-Museum.

The arrival of this collection at CHM fulfills a dream that began for me in 2005 as I began work on History of LISP and first contacted Herbert Stoyan to timidly suggest he might contribute scans of selected items from his collection to CHM. His response — that he would be retiring in 3 years and needed to think about a permanent home for his collection — encouraged me to think that CHM might be the recipient. To get here from there, many people played important roles. At the risk of forgetting someone, I would like to thank Alex Bochannek, Grady Booch, Elizabeth Borchardt, Richard Gabriel, William Harnack, John Hollar, Paul Jabloner, Al Kossow, Karen Kroslowitz, Sara Lott, Bernard Peuto, Len Shustek, Dag Spicer, Herbert Stoyan, Kirsten Tashev, and JonL White. In addition, CHM volunteers John Dobyns and Randall Neff have labored to survey, pack, and catalog portions of the collection. (Additional volunteers would be welcome!)

Update 9/22/2010: corrected URL for Whetstone at Software Preservation Group website.

The ALGOL 58/60 implementations for which I’ve been able to find source code for include:

• Burroughs 205 (Knuth)
• Burroughs 220 (Erdwinn et al.)
• Burroughs B-5500
• DEC PDP-10 (Habermann et al.)
• Electrologica X1 (Dijkstra and Zonneveld – Mathematisch Centrum)
• Electrologica X8 (Kruseman Aretz – Mathematisch Centrum)
• Electrologica X8 (Bron et al. – Technische Hogeschool Eindhoven)
• Elliot 803 (Hoare et al.)
• English Electric Whetstone (Randell and Russell)
• G.E.C. process control computer (Higman)
• Regnecentralen GIER (Naur et al.)
• Stantec Zebra (van der Mey – Netherlands PTT)

The appendices to Maurice Halstead’s book Machine-Independent Programming (Spartan Books, 1962) contain compiler source listings of Neliac (an ALGOL 58 dialect) for the UNIVAC M-460, IBM 704, and CDC 1604.

I also found compiler source code and listings for several versions of ALGOL W.

I’ve just gotten started looking for ALGOL 68 implementations.

I welcome your comments, corrections, and suggestions for the ALGOL web site.

In a recent oral history I conducted for the Computer History Museum, Don put into context his work designing SQL in collaboration with Ray Boyce. Don described the pre-relational database management systems, Ted Codd’s development of the relational model, various implementation projects at IBM culminating in System R, which was the first RDBMS to support SQL. Don went on to describe other pioneering relational systems, including Ingres and Oracle. He also described his subsequent work on text processing, DB/2, and XQuery.

For further historical information about Don and his work, see:

• Burt Grad, Moderator. RDBMS Workshop: Technology Through 1983, Computer History Museum, June 12, 2007. http://www.computerhistory.org/collections/accession/102658267
• Donald D. Chamberlin, OH 329. Oral history interview by Philip L. Frana, 3 October 2001, San Jose, California. Charles Babbage Institute, University of Minnesota, Minneapolis. http://www.cbi.umn.edu/oh/display.phtml?id=317
• Paul McJones, editor. The 1995 SQL Reunion: People, Projects, and Politics. Technical Note 1997-018, Systems Research Center, Digital Equipment Corporation, August 1997.
  http://www.hpl.hp.com/techreports/Compaq-DEC/SRC-TN-1997-018.html

The lecture was in the form of an interview by New York Times technology reporter John Markoff, who noted:

The Internet has many fathers, but few deserve the label more than Robert W. Taylor.

Authors M. Mitchell Waldrop (The Dream Machine) and Michael A. Hiltzik (Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age) shared their views as well. J Strother Moore and Gary Chapman (who each worked with Bob in the past and now have UT positions) served as masters of ceremony.

The announcement for the lecture includes links to news stories about Bob, as well as the famous 1968 paper by Licklider and Taylor, “The Computer as a Communication Device”. The recap of the lecture includes links to a video and photographs.

Here are summaries of the contents (corresponding to the six videotapes):

1. Taylor’s childhood, education, military service in the US Navy during the Korean War, and his first positions after graduating from college: teaching at a prep school in Florida, and systems engineering at The Martin Company in Orlando, Florida; managing research at NASA and at ARPA IPTO.
2. The ARPANET project, the founding of the graphics work at the University of Utah; his own brief stay at the University of Utah; the founding and early history of the Xerox PARC Computer Science Laboratory (CSL); Xerox’s purchase of Scientific Data Systems (SDS), and CSL’s MAXC, Alto, and EARS projects.
3. More on the Alto system and what it influenced (including TCP/IP); the Future Day held by PARC for Xerox executives; the Dorado project.
4. His departure from Xerox; the founding of the DEC Systems Research Center (SRC); the Firefly, Alpha Demonstration Unit, Autonet, AN2, and Petal projects; the founding of the DEC Paris Research Laboratory and its collaboration with SRC; the nearby DEC Western Research Laboratory (WRL) and its Titan project; a recap of the commercialization of Ethernet.
5. Wes Clark, his TX-2 work, his LINC work, and his suggestion of decentralizing control for the ARPANET via a small computer (IMP) at every host; Taylor’s work in Vietnam at the end of his ARPA tenure; his approach to research management, including recruiting, interviewing, and performance appraisals.
6. More on research management: informal celebrations, and the importance of a college intern program; reminiscences about people who worked at Xerox PARC CSL or DEC SRC or both.

The available books include:

• Aho and Ullman: The theory of parsing, translation, and compiling
• Apple: Macintosh human interface guidelines
• Brinch Hansen: Operating system principles
• Brinch Hansen: The architecture of concurrent programs
• Codd: The relational model for database management: version 2
• Dahl, Dijkstra, and Hoare: Structured programming
• Denning: Cryptography and data security
• Goldberg and Robson: Smalltalk-80: the language and its implementation
• Hoare and Jones: Essays in computing science
• Hopcroft and Ulman: Formal languages and their relation to automata
• IBM: IBM system/360 principles of operation
• Papert: Mindstorms: children, computers, and powerful ideas

Update: I had neglected to include the book by Aho and Ullman..

Update: The URL above for the ACM Classic Books Series was updated to http://www.acm.org/classics.

• Kent M. Pitman. The Revised MacLisp Manual. “Saturday Morning Edition”, M.I.T. Laboratory for Computer Science Technical Report MIT-LCS-TR-295, June 1, 1983.

This has been out of print for many years, but Kent just made available an updated, hypertext “Sunday Morning Edition”.

If you are interested in more MacLisp history, including earlier manuals, source code, and more, see the MacLisp area of the Lisp website at the Computer History Museum.

If you’re interested, the show will be broadcast at various times December 18 and 19 (today and tomorrow); local schedules are available at this web page:
http://www.bbc.co.uk/cgi-bin/worldservice/psims/ScheduleSDT.cgi

The Fortran segment starts at about 19m38s into the show.

Update 2: With the permission of BBC Radio, I’ve added the audio of the Fortran segment to the Memoirs and user stories section of the CHM Fortran web site:

• Gareth Mitchell, presenter. Fortran is 50. Digital Planet programme, BBC Radio World Service, December 18, 2007, 6′:40″. MP3 (7.6 megabytes)
  

  Mitchell interviews Paul McJones on the occasion of the 50th birthday of Fortran; additional commentary by Bill Thompson; produced by Helena Selby.

Update: A BBC reorganization removed the download link from the page above; in a comment below, Derek Mahar notes the episode download site is now http://www.bbc.co.uk/radio/podcasts/digitalp/ and this download itself is http://downloads.bbc.co.uk/podcasts/worldservice/digitalp/digitalp_20071218-1232.mp3

By the way, what was previously called the Software Collection Committee at the Computer History Museum has a new name (the Software Preservation Group), a new domain name (www.softwarepreservation.org) and a new chairman (Al Kossow, the Museum’s Software Curator and the creator of www.bitsavers.org).

In early 1974 I was looking for a job. My friend Jim Gray, who was then working at IBM Research in San Jose, introduced me to John, who was looking for someone to work with him on the design of his Red language and to implement an interpreter. We seemed to hit it off, and in March I accepted his employment offer. John mostly worked out of his home in San Franscisco. We discussed the possibility of locating my office in IBM’s Palo Alto Science Center, but I wound up joining the staff of IBM Research in San Jose, which was then located in the triangular Building 28 of the IBM Cottle Road Campus. John began driving down to San Jose once or twice a week in his diesel Mercedes. The only place in the area he could refuel was a truck stop in North San Jose. IBM colleagues told me I’d had an immediate positive impact: they now saw John much more than before.

For the next 15 months or so, I worked with John, discussing language features, writing various prototypes in Lisp and McG (an ISWIM-like language by W.H. Burge), reading papers on programming language semantics, and writing a report “A Church-Rosser Property of Closed Applicative Languages” that showed the operational semantics for Backus’s Red language was well-defined.

John was an inspiring person to work for and with. Despite his accomplishments (inventor of Fortran and BNF; Algol contributor; IBM Fellow) and the age difference (he started work at IBM the year after I was born), he treated me like he treated everyone: as a respected colleague. I had many suggestions for changing and extending Red, and John gave them all his complete attention. At that time, John was interested in pure functional programming, with no side-effects on storage or the external world. I advocated extending the language to allow writing complete interactive applications. John conceded the importance of this, and came up with a scheme in which one would write a function to express the complete transformation of an application on the global state. I struggled with John’s variable free style, and suggested we allow lambda variables when defining a new functional form (higher-order function), but he stuck to his guns. Gradually, I came to the conclusion that it was still too early to build a full implementation of Red, and I began spending more time talking to the System R team down the hall, who were designing one of the first relational database managers, and inventing the SQL query language and formalizing atomic transactions along the way.

John rarely wanted to talk about himself, but when asked he had interesting stories to tell. When he first joined IBM, he programmed the Selective Sequence Electronic Calculator (SSEC), a huge electromechanical machine whose programs and data were punched into a paper tape the width of regular 80-column punched cards, but many feet long. By gluing a data tape into a loop, it could be traversed multiple times. John recalled having to debug a program that would go through cycles of correct and incorrect behavior. Eventually they realized that the tape had a half-twist when it was glued into a loop, converting it into a one-sided Möbius strip.

John’s 25th service anniversary at IBM was in 1975. A recognition luncheon was planned in San Jose (at the IBM Country Club, or customer conference center), and John was asked who he’d like to attend. He named several of his current San Jose colleagues (I was honored to be included), as well as his old colleagues from the 1950s, including people from the Fortran project. The person arranging the event said, “But these people are in New York…”, and then came up with the travel expenses.

Cordial relations with John were not restricted to working hours. He and his wife Barbara invited my wife and me to dinner at their home, which turned out to be near the base of the Sutro Tower, with a beautiful view looking north from the Golden Gate bridge to the east bay. John said the only disadvantage of the location was RF interference to his stereo from the television transmitters. To combat this, he’d designed a Faraday cage by lining his equipment closet with aluminum foil. We invited John and Barbara back to our modest rental in San Jose, and they graciously accepted.

When I started at IBM, Nixon was still in office. John’s distaste for Nixon was no secret to his friends at the time. He learned he was one of seven people singled out to receive a “Presidential Prize for Innovation”, but then the plans were dropped. John later wrote that he “had been secretly planning to use the occasion to denounce Nixon and the Vietnam war. … I guess now my plan was not a gentlemanly scheme, but anyway I was relieved when the plan fell through.”

I stayed at IBM until November 1976, working on the System R recovery manager with Jim Gray, and then moved on to another job. A while later, I ran into John waiting in line for one of the West Coast Computer Faires — probably the first one, in 1977 in San Francisco. John told me he’d sent a deposit on an interesting computer called the MicroMind, from an outfit in Cambridge, MA, called ECD Corp. He was beginning to be skeptical that he would ever get a computer or his money back. I recently heard from Olin Sibert that ECD couldn’t build the machines cheaply enough, and returned all the deposits.

In 1977 John received the ACM Turing Award for “profound, influential, and lasting contributions to the design of practical high-level programming systems, notably through his work on Fortran, and for seminal publication of formal procedures for the specifications of programming languages.” John’s Turing Lecture, “Can Programming Be Liberated from the von Neumann Style? A Functional Style and Its Algebra of Programs” was devoted to his functional programming work, and had a large impact on the growth of a branch of academic computer science studying functional programming languages. John continued to work on functional programming until he retired in 1991.

I fell out of touch with John for many years. But in 2003, an effort I became involved with at the Computer History Museum to collect and preserve historic source code led me to get in touch with John regarding the original Fortran compiler. John was still living in the same house in San Francisco, and seemed pleased to hear from me. He didn’t have any source code, but did make several suggestions; eventually I found several versions of the IBM 704 FORTRAN II compiler source code.

Around this same time, I learned that John’s idea of an algebra of programs had had a big impact on my colleague Alex Stepanov (although Alex figured out how to apply this idea while extending the “von Neumann style” in an important way). At the time, Alex and I were organizing an internal technical conference for our employer, and we invited John to give a keynote speech. Just after he graciously accepted, his wife Barbara died; understandably he canceled the speech. John decided to move to Ashland, Oregon, to be near one of his daughters. Another colleague of mine, Dick Sweet, lives in Ashland and introduced John to a new circle of friends for what turned out to be his final years.

Although many people contributed to the early development of programming languages, John Backus deserves credit for creating the first successful higher-level programming language, Fortran. Fortran provided data types (integer and floating-point numbers), a powerful data structure (the array), expressions, statements, and abstraction mechanisms (functions and subroutines). The Fortran compiler generated optimized code taking advantage of the then brand new index registers and floating-point hardware of the IBM 704. Finally, the Fortran system provided a linking loader, a subroutine library, and I/O routines. The scientific and engineering users adopted it instantly, and it became the standard against which future programming language designs were compared.

Why was John’s contribution so important? He invented a language allowing one to express numeric algorithms in a way that was abstracted from irrelevant details of particular computers but that was efficiently implementable on a broad class of computers: from the vacuum tube IBM 704 of 1954 to the fastest supercomputer of 2007 and beyond. That idea, allowing the essential details of algorithms and data structures to be expressed in an abstract and yet efficient way, is at the heart of what programming language designers have been trying to accomplish for the last 50 years. Only a handful of them have made the kind of progress John Backus and his team did.

• FORTRAN 25th anniversary film, 1982, 12.5 minutes. Computer History Museum lot number X2843.2005, donated by Daniel N. Leeson. Windows Media Video (12.8 megabytes)

(Daniel N. Leeson describes this film in his article “IBM FORTRAN Exhibit and Film” in Annals of the History of Computing, Volume, 6, Number 1, January 1984, pages 41-48. He describes the production of the film in some detail, and includes a complete transcript.)

Thanks go to Micah Nutt for supplying me a DVD dub of the video, which I transcoded using Adobe Premiere Elements 2.0.

The first version of the memo says:

The FORTRAN II translator will accept an unlimited number of different statements. All statements presently in the system and a few others to be described below will be recognized and translated in the normal way. All others will refer to subroutines and must have the following form:

NAME ( A, B, C, I, X )

where NAME denotes the name of the desired subroutine to be executed. Enclosed in parentheses are the names of variable and/or arrays which the subroutine is to operate on and also the names of variables and/or arrays which are to receive the results produced by the subroutine. Variables may be fixed or floating point. After the subroutine has been executed the next executable statement in the FORTRAN program will be executed.

In this version, a subroutine begins with a SUB DEF statement, which also includes the name and argument list. There is a RETURN statement, but no END statement.

In the second version, SUB DEF becomes SUBROUTINE DEFINITION, and the END statement appears. An UPPER statement is added, for definining variables and arrays that will be allocated at the high end of memory, where they can be accessed from more than one subprogram.

In the third version, a subroutine call begins with the reserved word CALL. The UPPER statement becomes the COMMON statement.

By the time FORTRAN II shipped and the manual was published, a FUNCTION statement was added.

The last page of this 1959 research report by Grace Mitchell describes the changes that were required to add these features to the compiler.

In his 1978 HOPL paper (see here or here or here), Backus noted, “FORTRAN II was designed mostly by Nelson, Ziller, and myself. Mitchell programmed the majority of new code for FORTRAN II (with the most unusual feature that she delivered it ahead of schedule). She was aided in this by Bernyce Brady and LeRoy May. Sheridan planned and made the necessary changes in his part of section 1; Nutt did the same for section 6. FORTRAN II was distributed in the spring of 1958.”

Today the ability to build programs from separately compiled units is taken for granted, but 47 years ago this was a big thing. Recently Dennis E. Hamilton, who remembers the release of FORTRAN II, told me:

“However, the impact of small changes and improvements can be immense. The ability to build Fortran programs out of independently-compilable modules and to have the ability to decompose into functions and subroutines using Fortran or any other tool that produced compatible code (usually the assembler, in those days) had an immense impact. In Fortran I programs were one giant file and there was no modularization structure. That small change in Fortran II was earthshaking in terms of software development and, I think, the endurance of Fortran as a technical-software programming tool.

It also changed the way that computers had to operate to make software building and use work more smoothly. I think it is no coincidence that this paralleled increased interest in operating systems (called things like tape monitors, at the time) and the use of the computer for organizing the data processing workflows. (There was also a lot of resistance to operating systems in those days.)”

For much more about the FORTRAN/FORTRAN II project, visit the Computer History Museum’s History of FORTRAN web site.

At the recent International Lisp Conference, I gave a short presentation, and afterwards several LISP pioneers chatted with me. Lynn Quam volunteered to provide me with scanned copies of a number of historic documents concerning LISP 1.6: SAILON 28.1 (compare with MIT AIM-116a), SAILON 28.2, SAILON 28.3, and SAILON 28.6, as well as memos describing various library packages.

Lynn also provided a copy of Stanford AIM-90, the 1969 Standard LISP specification by Anthony Hearn. Hearn designed Standard LISP as an abstraction layer upon which his REDUCE computer algebra system was implemented. AIM-90 included a 5-page appendix of definitions to make Stanford’s LISP/360 conform to Standard Lisp. (The later Portable Standard LISP project was a from-scratch implementation.)

• John McCarthy, Paul W. Abrahams, Daniel J. Edwards, Timothy P. Hart and Michael I. Levin. LISP 1.5 Programmer’s Manual. The M.I.T. Press, 1962, second edition. PDF
• Berkeley and Bobrow, editors. The Programming Language LISP: Its Operation and Applications. Information International, Inc., March 1964 and The MIT Press, April 1966. PDF

In addition to these I have continued to track down information about more versions of LISP, so the web site keeps growing.

I also gave a brief announcement of this project at the recent International Lisp Conference 2005, and a number of people volunteered to help me track down more information.

If I’ve neglected your favorite version of LISP, please go through your closet or basement and find those manuals, listings, mag tapes, etc.