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Calvin N. Mooers papers

Identifier: CBI 81

Scope and Content Note

The collection contains personal correspondence of Calvin N. Mooers, and records of Zator Co., founded in 1947, and Rockford Research Institute, Inc., founded in 1961. Subjects found in the Zator Co. and Rockford Research Institute, Inc., records include information processing and retrieval, a punched card system known as Zatocoding, library and information science, a programming language that Mooers helped design called TRAC (Text Reckoning and Compiling language), programming languages standards, and reactive typewriters.

An additional donation of materials in 2000 (boxes 27-29) include Mooers' copies of his notebooks from the Naval Ordnance Laboratory (1944-1946); selected entries from Mooers' personal diaries during the same period; correspondence in regard to Mooers' testimony in the Honeywell vs. Sperry Rand patent case; correspondence relating to Mooers' two lectures at the University of Pennsylvania Moore School lecture series and unedited transcripts of his lectures. Also included are Mooers' "reminiscences," 1982, 1984, and a memoir, dated 1990.

Mooers' initial arrangement of the materials has been largely retained. For accessibility, the contents listing has been arranged alphabetically. Researchers should search for personal names in both normal (i.e., given name followed by surname) and inverted (i.e., surname, given name) forms as some entries were constructed in different ways.

A 2007 donation was arranged and described separately and is listed at the bottom of this finding aid. The donation includes Mooers' publications and other professional documents, including information about SIMPL!E, TRAC and SIMON, VXM and Command Technologies. Documents from Mooers' work at Rockford Research, Inc. and Zator Company are included in subseries in his Professional Subject and Working Files.


  • 1930-1992


Language of Materials


Access to materials:

Access to the collection is unrestricted.


The Charles Babbage Institute holds the copyright to all materials in the collection, except for items covered by a prior copyright (such as published materials). Researchers may quote from the collection under the fair use provisions of the copyright law (Title 17, U.S. Code).

Biographical Note

Calvin N. Mooers was the founder and research director of Zator Co. and founder, president, and research director of Rockford Research Institute, Inc. He conducted research on the development and use of information retrieval systems and created the Text Reckoning and Compiling (TRAC) programming language, which was designed specifically to handle unstructured text in an interactive mode, i.e., by a person typing directly into a computer.(Sammett, 449)

Mooers became interested in mathematics from his involvement with amateur radio and through the encouragement of Viola Marti, his high school mathematics teacher. While he was still a high school student, his teacher introduced him to a mathematics professors at the University of Minnesota. They encouraged Mooers' abilities and, after three years at the university, Mooers began taking graduate courses in mathematics and physics. In the spring of 1941, Professor Lynn H. Rumbaugh, from whom Mooers had taken theoretical physics, recruited him to join the Naval Ordnance Laboratory (NOL) in White Oak, Maryland as a physicist, where he worked on degaussing (the protection of ships against magnetic mines). While at NOL he met Charlotte Davis from the Acoustic Division. They married in 1945 and their union continued for 49 years until his death. At the end of World War II, NOL reorganized and Mooers became part of NOL's newly created Computer Division where he worked under John Vincent Atanasoff. (Mooers 1993)

Frustrated by his belief that we were just not getting anywhere at NOL in our computer project,Mooers left NOL in 1946 for graduate school at MIT hoping to capitalize on his computing experience. Mooers set out to explore the use of digital processes and mathematics to impose control on the technical reports then flooding out of government laboratories. At MIT, Mooers discussed his ideas with James W. Perry, a chemist interested in indexing and finding chemical information. Perry arranged at an American Chemical Society meeting for Mooers to present his ideas on the development of a machine capable of Boolean searching. In his paper, Mooers advocated that chemists should be involved in the development of such a machine. (Mooers 1951)

His research led Mooers to invent Zatocoding (Mooers 1950), which he described as a complete system. In terms of contemporary lingo,... [i]t was non-electronic, which equals mechanical; it was digital; it would be called a knowledge-based system; it was a selector device (you didn't pick the cards out by hand); it was automatic, in other words, a motor drove it; and it exploited the Zatocoding technique which can be characterized as selection based upon fuzzy sets.Zatocoding used a series of specially notched cards. Each notch was a descriptor representing information in the document to which that card referred. Mooers later commented that Zatocoding antagonized librarians... I was describing an operation which [replaced] live human librarians... This was contrary to their vitalistic idea. They believed you had to have a living human brain to perform such a selection. Yet, I was trying to demonstrate that you could do it mechanically. I did it, and it worked!

To develop practical applications for Zatocoding and market them, Mooers formed the Zator Company with his brother Howard in 1947. After a year and half it was clear that it [Zatocoding] would not be an overnight success,... so we parted amicably.Mooers remained in Cambridge conducting information retrieval research and marketing Zatocoding until the mid-1960s when he again turned his professional attention to computers. Much later, the American Society for Information Science (ASIS) recognized Mooers' pioneering efforts in information retrieval, a term which he had coined, when it presented him with its Award of Merit in 1978.

During the 1950s and early 1960s, Mooers conducted a number of information retrieval studies for government agencies. Raymond J. Solomonoff joined Zator Company in 1957, adding artificial intelligence to its research capabilities and Zator received one of the first federal grants for artificial intelligence research from the Air Force Office of Scientific Research. In 1959, Mooers began to develop the Text Reckoning and Compiling (TRAC) language. Mooers founded the Rockford Research Institute, Inc., a non-profit corporation, in the early 1960s to facilitate his and Solomonoff's grant-funded research.

In 1964, Mooers defined TRAC. Jean Sammet, in her Programming Languages: History and Fundamentals, noted that TRAC has combined concepts of LISP, COMIT, and macro facilities in a very unusual way... The basic concept in TRAC is that a program consists of strings containing sequences of functions which can be nested indefinitely deeply. Evaluations of these proceed from the innermost level outward, and from left to right within a level, to cause the execution of a program. Furthermore, since the executable statements are treated in the same way as a general character string, a procedure can act upon itself as well as other executable statements, thus giving completely general self-referencing capabilities.(Sammet, 450)

Mooers hired L. Peter Deutsch to program TRAC on a PDP-1 at Bolt, Beranek and Newman (BBN) and submitted a descriptive account to Communications of the ACM in 1965. He recalled the editors, when it came in, evidently were amazed since they had never heard of me. Of course they hadn't heard of me. I hadn't talked about programming languages. I wasn't one of the `big names.' So I came in with this finished piece of work, and they sent two of their big wheels out to look me over. One of them was Carlos Christensen and the other was Robert Floyd, a big wheel in parsing programming languages. They came to visit me at the office to find out who this guy Mooers was and how come they'd never heard of him. I brought them into the office and took them into the back room and turned on the teletype and we were in remote communications -- with a remote computer at BBN on which TRAC was running and I demonstrated it. So they were all ready to deflate a hoax! Quite different was the fact of the matter. So my paper was published.(Mooers 1966)

Mooers tried to make a commercial success out of TRAC and found there were no rights in computer software, the ideas were `foreign.' There was the belief in the legal profession that neither copyright nor patent would apply.Although he tried to protect TRAC as a trademark and service mark TRAC probably became the most widely bootlegged computer intellectual property that existed... the first issue of Dr. Dobb's Journal, one of the early publications in the personal computer field, has a vitriolic editorial against Mooers and his rapacity in trying to charge people for his computing language.Mooers' advocacy of protecting the intellectual property of software included a brief exchange of ideas with Bill Gates. Mooers later worked with Thorpe Wright and Andy Diamond at the firm Data Concepts on the application of TRAC to write insurance policies. After using TRAC to complete a policy writing program named SIMPL!E, Data Concepts declared bankruptcy before it could realize commercial success.

After his work with Data Concepts, Mooers spent time reformulating... the whole TRAC methodology and defined TRAC-II in 1983. Franco Vitaliano got very interested in the intellectual achievement... of TRAC-II and he thought he could commercialize it... Franco was able to catch the attention of many people, but was not really able to sell it.Mooers and Vitaliano parted ways after several years and Mooers continued to develop TRAC-II. He used it as the basis for developing a system he demonstrated at BBN for paging through documents via Telnet similar to the capabilities later exploited with Gopher, but, as his wife Charlotte commented, this, again, was a situation where there was a window of opportunity that wasn't taken.

Until his death in late 1994, Mooers explored using TRAC-II in combination with object-oriented programming on personal computers and remained an active participant in the field.

All quotations, except as noted, are from the Calvin N. and Charlotte D. Mooers oral history interview, 22 June 1993, OH 254, Charles Babbage Institute. Adapted from an obituary written for IEEE Annals of the History of Computing.


  1. Mooers, Atanasoff at the Naval Ordnance Laboratory,Ann. Hist. Comp, 15:2 (1993), 54-55.
  2. Mooers, TRAC, a Procedure-Describing Language for the Reactive Typewriter,CACM, 9:3 (March 1966), 215-219.
  3. Mooers, Putting Probability to Work in Coding Punched Cards: Zatocoding (Zator Technical Bulletin No. 10), 1947. Reprinted as Zator Technical Bulletin No. 30 (1950).
  4. Mooers, The Zator-A Proposal: A Machine for Complete Documentation, 1947. Reprinted with preface as Zator Technical Bulletin No. 65 (1951).
  5. Jean E. Sammet, Programming Languages: History and Fundamentals (Englewood Cliffs, NJ: Prentice-Hall, 1969)


39 boxes (37 cubic feet)


Collection contains personal correspondence of Mooers, and records of Zator Co., founded in 1947, and Rockford Research Institute, founded in 1961. Subjects found in the Zator Co. and Rockford Research Institute records include information processing and retrieval, a punched card system known as Zatocoding, library and information science, a programming language that Mooers helped design called TRAC (Text Reckoning and Compiling language), programming languages standards, and reactive typewriters.


The records were given to the Charles Babbage Institute by Calvin N. Mooers in 1987. Subsequent accruals were given to CBI in 2000 by the Mooers family and in 2007 by Helen Solorzano.

Calvin N. Mooers Papers, 1930-1992. Finding Aid.
Prepared by Kevin D. Corbitt, November 1992; revised by Elisabeth Kaplan, December 2000; revised by Stephanie Horowitz Crowe, January 2009.
Language of description
Script of description
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