Code Nation. Michael J. Halvorson

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СКАЧАТЬ to use hand-written notes (as well as cumbersome mechanical devices) to accomplish their work, and in these contexts, errors crept in.²¹

      A complete FORTRAN program consisted of a deck of punched cards that a technician could feed into a card reader, which was attached to the mainframe computer. Once the program was loaded into memory it could be compiled, and the technician would receive a report if there were any errors. The process of debugging the program then began, which could take some time to complete and might involve many team members. In batch-processing contexts like these (i.e., before interactive terminals with keyboards), it might take days or weeks to fix a relatively simple logic or runtime error in a program. Debugging

      My favorite textbook describing this process for new programmers is Marshal H. Wrubel’s A Primer of Programming for Digital Computers (1959).²² This well-written book includes step-by-step instructions for filling out coding sheets, creating punched cards, loading cards into an IBM 650 system, and then testing programs using a variety of methods. There is also a fascinating chapter comparing the early FORTRAN, IT, and FORTRANSIT compilers—all designed to help scientists solve math problems. Marshal Wrubel (1924–1968) was a Juilliard piano prodigy and a University of Chicago astrophysicist who took up computing in the 1950s and eventually ran the Research Computing Center of Indiana University. He is relatively unknown in the history of computing because he died unexpectedly at the age of 42 on a hike in the mountains of Colorado. Sadly, he published this innovative primer but nothing more about programming. However, he made an important contribution to technical writing with this title.

      The first official manual to document the FORTRAN compiler arrived in October 1956, when IBM released the Programmer’s Reference Manual.²³ This formal guide offered a short introduction to FORTRAN and gave experienced programmers the information they needed to use the compiler on the IBM 704 system. The book carefully documented each new language feature, highlighting the language’s Formula translation (FORTRAN)keywords and grammar, or what programmers called Statement syntaxstatement syntax. The manual also included a short chapter on how to create solutions for two “sample problems.”

      Soon after this, a selection of user-friendly primers teaching FORTRAN began to appear. These introduced the language to a broader audience (i.e., not just IBM customers). These books included Grace E. Mitchell’s Mitchell, Grace E.Programmer’s Primer (1957), Daniel McCracken’s A Guide to FORTRAN Programming (1961), and Elliott Organick’s A Primer for Programming with the FORTRAN Language (1961).²⁴ These books demonstrate that the nascent programming movement was spreading beyond research labs and academic contexts into settings where quantitative calculations were part of everyday work.

      As primary sources for historians, the first FORTRAN primers provide evidence of how coding was gradually seeping into public consciousness. Students, business people, and engineers were now the audience for these books, rather than IBM customers who were using just one system. The computer books also document literary developments in technical writing, i.e., the use of a less-formal “author voice” in scientific descriptions. Some of the books felt open-ended, engaging a wider audience. The tutorials also benefited from the gradual shift from batch-processing to time-sharing, which allowed for greater access to computers and a more interactive experience.

      Grace E. Mitchell’s Programmer’s Primer was among the most influential books of this era for budding technical writers. (See Figure 3.7.) Although Mitchell was uncredited in the text and the book was published as an IBM reference manual, it was just as pioneering as the commercial tutorials published by mainstream publishers.

      Mitchell joined IBM’s FORTRAN group in the Spring of 1957, and she made important contributions to the FORTRAN II compiler release, as well as IBM’s newest operating systems and programming tools. Although Mitchell possessed formidable engineering skills, her Primer was designed for non-programmers who were preparing to take their first steps with a new language. In reality, readers did need some knowledge of college algebra, trigonometry, and matrix operations to make much use of this book. But no specific computer knowledge was required, and Mitchell assumed that programming would be an entirely new concept. In 1957, most of IBM’s FORTRAN users were scientists who were well-trained in engineering but knew little about computers. Formula translation (FORTRAN)

      

      Figure 3.7Programmer’s Primer for FORTRAN: Automatic Coding System for the IBM 704 (1957). Grace E. Mitchell was the uncredited author of this early “how to” programming tutorial from IBM. (Courtesy of the Computer History Museum)

      Mitchell’s primer offered a concise analysis of FORTRAN’s core features, including some of the complexities only hinted at in the original Reference Manual. (See Figure 3.8.) For example, Mitchell included a lengthy section on working with two- and three-dimensional arrays in FORTRAN I. The tutorial explored how to declare arrays, assign initial values, and step through arrays using DO loops and other control structures.Arrays²⁵ Mitchell also included practical information about debugging unruly programs, a topic that was largely neglected in the Reference.

      

      Figure 3.8Excerpt from Mitchell’s Programmer’s Primer (1957, page 44), showing how to write a FORTRAN program that computes matrix multiplication. The FORTRAN code was displayed on a standard coding sheet, making it easier to identify the columns, statement numbers, and language elements needed. (Courtesy of the Computer History Museum)

3.5Daniel McCracken’s primersDaniel McCracken’s Primers

      Daniel D. McCracken (1930–2011) also established his reputation as a programming author, publishing some of the first general textbooks about software development in the U.S. (See Figure McCracken, Daniel3.9.) McCracken wrote his first computer book at the age of 24 while working for General Electric, a 256-page text entitled Digital Computer Programming that appeared during the fall of 1957.²⁶ This title was published by John Wiley & Sons, one of the first computer book publishers. Wiley went on to develop an international reputation for reliable computing titles in several categories. The influential acquisitions editor at Wiley who worked with McCracken was Walker Stone, a determined technologist who had taken a few programming courses in the 1950s and quickly recognized the computer’s importance and value.Daniel McCracken’s primers²⁷ Stone oversaw technical publishing at Wiley for several years, establishing the Information Science Series and other well-regarded imprints.

      

      Figure 3.9Former ACM President and computer book author Daniel D. McCracken. (Image courtesy of the Charles Babbage Institute, University of Minnesota Libraries)

      Looking back at his career, McCracken said that he wrote the Wiley book in 1957 because there was no textbook available for programmers, and he wanted to write one that described the features of a “hypothetical machine,” which he conceived of as a cross between an IBM 704 and an IBM 650.Hypothetical machine²⁸ Using this platform, McCracken introduced students to basic programming concepts like looping, branching, input, output, and floating-point arithmetic. The textbook had a relatively limited appeal because of its narrow audience (at the time, his book competed with the second Daniel McCracken’s primersedition of Maurice Wilke’s book on EDSAC programming), but McCracken’s text did find its way into some of the earliest programming courses in America. For example, Jean Sammet is reported to have used McCracken’s book at Adelphi College on Long Island soon after its release.Sammet, СКАЧАТЬ