1960s Electronic Typing Technology

The 1960s was the first “information overload” decade, as the capacity to produce business/professional documents and paperwork increased exponentially and the need to organize and manage it grew right alongside.  Information management technology, relatively primitive at this time, did not hold ready solutions.

IBM was the 800 pound gorilla of the day.  The Selectric typewriter, introduced in 1961, was a technological marvel which quickly became the workhorse standard typing machine for business and professional use and remained so for nearly three decades.  According to Wikipedia, “Selectrics and their descendants eventually captured 75 percent of the United States market for electric typewriters used in business.”  But the Selectric produced paperwork, it didn’t manage it.

Word Processing 

IBM’s big play into the information management space came with the IBM MT/ST machine, launched in 1964.  The MT/ST, which stands for “Magnetic Tape / Selectric Typewriter”, was a standalone word processing system powered by a Selectric machine.  It launched to great fanfare, was hailed by IBM president Gordon M. Moodie as a “radically new concept in typewriting which will change the traditional approach to typing jobs at thousands of typing stations around the country”.

The MT/ST contained two magnetic tape cartridges that could store and edit inputs then play back the output along with a control panel that an operator would use to make revisions.  It was a very sophisticated machine for its day.

A Selectric cost around $500 while the MT/ST came in at nearly $10,000.  To deal with this IBM put the  MT/ST to the Office Products Division (not in the Selectric division) which was focused on the executive suite, marketing the concept of “power typing” (documents that required lots of revision, form letters, forms, transcribed dictation) and selling dictation machines and other peripherals as well as setup consulting,  to provide a comprehensive information management solution.  The effect was to directly yoke an executive’s microphone to the secretary’s keyboard, thus ensuring that a single sales representative now handled a complete system for the origination, revision, and duplication of text.  This is a business plan!

This story is beautifully told by Matthew Kirshenbaum in “Track Changes: A Literary History of Word Processing”.  IBM was so bullish on this project that in 1967 they commissioned the Jim Henson Company to produce a short film about the MT/ST called “The Paperwork Explosion”.

For the most part “power typing” consisted of letters, numbers and punctuation… not scientific or mathematical notation.  It is unlikely that many MT/ST documents contained sub/superscripts or other esoteric symbols.  

For more sophisticated typography IBM introduced the “Selectric Composer” in 1966 followed by the “Magnetic Tape Selectric Composer” in 1967.  Using a highly modified Selectric mechanism, these machines produced camera-ready justified copy using proportional fonts in a variety of font styles from eight to fourteen points.  This machine was more designed for technical typing. 

Here is a mathematical article with lots of symbols and superscripts, produced on a Selectric Composer in the 1970s.

These MT/ST machines, these office management solutions, had the full weight of IBM’s brand marketing behind them… but they were first generation stand-alone single purpose word processing machines, they were not controlled by computers and did not associate with computers.

Computer Line Printers  

Computers in the 1960s were too limited to do what IBM needed to get done with business office management… and text editing/word processing wasn’t the first mission for computers of this time either.  The first job of computers at the time was to become liberated from batch processed inputs that used paper punch cards, evolve to become interactive with users.  For much of the decade, the rock solid standard was for operators to feed punch cards into their computers then wait for their line printer to print out the results.  “Throwing around card decks” was one way of describing the situation.

IBM also dominated the business computer market during the 1960’s, and their most successful line printer was the 1403.  It was a workhorse machine… a print chain with up to 15 copies of the character set spun horizontally in front of the ribbon and paper. Hammers struck the paper from behind at exactly the right moment to print a character as it went by.  The original model could print 600 lines of text per minute and could skip blank lines at up to 75 inches per second.  It was a monster.

In 1968 Brian Kernighan printed his doctoral thesis on an IBM 1403.  As he describes it, “I did my thesis in the fall of 1968 at PU on IBM 1403 chain printers, which had no mechanism for subscripts or superscripts, so I was forced into notational contortions for the modest number of places where I needed them, and I did a handful of special characters with Type-its on a Selectric.”

His remarkable story of what is likely a historic event is told in his book “UNIX: A History and a Memoir”.

Click image for story excerpt
Click image to view actual typed copy from a 1403

Teletype Computer Terminals  

During the 1960s there were two primary companies producing computer teletype machines… IBM and the Teletype Corporation, which was a part of AT&T’s Western Electric manufacturing arm.  The best snapshot image we can find to describe the leading teletype machines of the mid-1960’s is a description from “Where Wizards Stay Up Late” by Katie Hafner and Matthew Lyon, pgs 12-13.  Referring to Bob Taylor, working for ARPA at the Pentagon in 1966, the authors relate…

… “The IPTO director’s suite, where (Bob) Taylor hung his coat from 1965 to 1969, was located in D-ring… Inside the suite, beside Taylor’s office, was another door leading to a small space referred to as the terminal room.  There, side by side, sat three computer terminals, each a different make, each connected to a separate mainframe computer running at three separate sites.  There was a modified IBM Selectric typewriter terminal connected to a computer at the Massachusetts Institute of Technology in Cambridge (ed:  confirmed by Alan Kaye to be an IBM 2741).  A Model 33 Teletype terminal, resembling a metal desk with a large noisy typewriter embedded in it, was linked to a computer at the University of California in Berkeley.  And another Teletype terminal, a Model 35, was dedicated to a computer in Santa Monica, California.”

NB: John Markoff interviewed Bob Taylor about the creation of the ARPAnet, very interesting article… 

Neither the Teletype Model 33 nor the Model 35 were much of a printer, neither one could even handle lower case letters.  These machines were not good candidates for printing mathematical or other technical papers.

The IBM 2741, on the other hand, was a teletype terminal with significant typographic possibilities.  Like the MT/ST word processor and its sister terminal the IBM 1050, the 2741 was built around the IBM Selectric typewriter which gave access to the full range of fonts on the golf-ball elements.

And IBM had been at it from the beginning.  When in November 1961, Fernando J. Corbató (Corby) demonstrated at MIT what was called the “Experimental Time-Sharing System” (which became the Compatible Time-Sharing System (CTSS)) at MIT, he was using an IBM 7090 computer attached to a 1050.  

Jerry Saltzer wrote RUNOFF and TYPSET originally for an IBM 7094 computer attached to a 1050.  He printed his doctoral thesis in 1966 on a 1050.

Image of a 2741

But IBM missed their chance to use the 2741 to catapult the company into the modern era.  As described in an IBM “Icons of Progress” historical memo…     

“Yet to IBM computer scientist Bob Bemer, the Selectric represented “one of the biggest professional failures of my life.” Bemer had pioneered the creation of the American Standard Code for Information Interchange, or ASCII, which still defines the alphabet for computers. When prototypes of the Selectric were already being manufactured at IBM’s typewriter plant in Lexington, Kentucky, Bemer reviewed the Selectric typewriter’s specifications. To him, the Selectric would make a natural computer keyboard. He argued that the type ball should be designed to carry 64 characters required for ASCII, rather than the typewriter standard 44. That would make it relatively easy to convert the Selectric for computer input. The response, as Bemer remembers it, was dismissive. As a result, the Selectric never spoke ASCII, instead employing a unique code based on the tilt and rotate commands to the golf ball. While Bemer viewed this as his failure, engineers continued to rig Selectric typewriters to function as the first generation of computer keyboards and input devices.”

There is a lot about the 2741 that we still need to uncover.  It didn’t communicate perfectly with computers but it did communicate well enough to be in prominent use throughout the decade and beyond.  

Dennis likely used a 2741 when he worked at MIT Project MAC using CTSS during graduate school.  Dennis had a 2741 terminal in his home office at Bell Labs, though we are not certain when this was installed.  

If there was a way that he used some form of computer assist to type his doctoral thesis, by far the most likely scenario would be that he used a 2741 rather than any other choice available at the time.  

We’ll keep hunting and update when we find more information.


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