![Flexowriter](https://upload.wikimedia.org/wikipedia/commons/e/e5/Flexowriter.JPG)
The Friden Flexowriter produced by the
Friden Calculating Machine Company, was a
teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point and point-to-multipoint configurations. Initia ...
, a heavy-duty electric typewriter capable of being driven not only by a human typing, but also automatically by several methods, including direct attachment to a computer and by use of
paper tape
Five- and eight-hole punched paper tape
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
Punched tape or perforated paper tape is a form of data storage ...
.
Elements of the design date to the 1920s, and variants of the machine were produced until the early 1970s; the machines found a variety of uses during the evolution of office equipment in the 20th century, including being among the first electric typewriters, computer input and output devices, forerunners of modern word processing, and also having roles in the machine tool and printing industries.
History
Origins and early history
The Flexowriter can trace its roots to some of the earliest
electric typewriter
A typewriter is a machine, mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of Button (control), keys, and each one causes a different single character to be produced on paper by striking ...
s. In 1925, the
Remington Typewriter Company
E. Remington and Sons (1816–1896) was a manufacturer of firearms and typewriters. Founded in 1816 by Eliphalet Remington in Ilion, New York, on March 1, 1873, it became known for manufacturing the first commercial typewriter.
History
The r ...
wanted to expand their offerings to include electric typewriters. Having little expertise or manufacturing ability with electrical appliances, they partnered with
Northeast Electric Company
The points of the compass are a set of horizontal, Radius, radially arrayed compass directions (or Azimuth#In navigation, azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east ...
of Rochester and made a production run of 2500 electric typewriters. When the time came to make more units, Remington was suffering a management vacuum and could not complete contract negotiations, so Northeast began work on their own electric typewriter. In 1929, they started selling the Electromatic.
In 1931, Northeast was bought by
Delco. Delco had no interest in a typewriter product line, so they spun the product off as a separate company called Electromatic. Around this time, Electromatic built a prototype automatic typewriter. This device used a wide roll of paper, similar to a
player piano
A player piano (also known as a pianola) is a self-playing piano containing a pneumatic or electro-mechanical mechanism, that operates the piano action via programmed music recorded on perforated paper or metallic rolls, with more modern i ...
roll. For each key on the typewriter, there was a column on the roll of paper. If the key was to be pressed, then a hole was punched in the column for that key.
The Electromatic typewriter patents document the use of pivoted spiral
cam
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the bind ...
s operating against a hard rubber drive roller to drive the print mechanism. This was the foundation of essentially all later electric typewriters. The typewriter could be equipped with a "remote control" mechanism allowing one typewriter to control another or to record and play back typed data through a
parallel data connection with one wire per typewriter key. The Electromatic tape perforator used a wide tape, with punch position per key on the keyboard.
In 1932, a code for the
paper tape
Five- and eight-hole punched paper tape
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
Punched tape or perforated paper tape is a form of data storage ...
used to drive
Linotype and other
typesetting
Typesetting is the composition of text by means of arranging physical ''type'' (or ''sort'') in mechanical systems or ''glyphs'' in digital systems representing ''characters'' (letters and other symbols).Dictionary.com Unabridged. Random Ho ...
machines was
standardized
Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...
. This allowed use of a tape only five to seven holes wide to drive automatic typewriters, teleprinters and similar equipment.
In 1933,
IBM wanted to enter the electric typewriter market, and purchased the Electromatic Corporation, renaming the typewriter the
IBM Model 01, and continuing to use the Electromatic trademark.
IBM experimented with several accessories and enhancements for its electric typewriter. In 1942, IBM filed a patent application for a typewriter that could print justified and proportionally spaced text. This required recording each line of text on a paper tape before it was printed. IBM experimented with a 12-hole paper tape compatible with their
punched-card code.
Eventually, IBM settled on a six-hole encoding, as documented in their automatic justifying typewriter patents filed in 1945. Equipping an electric typewriter with both a paper-tape reader and punch created the basic foundation for what would become the Flexowriter.
By the late 1930s, IBM had a nearly complete
monopoly
A monopoly (from Greek language, Greek el, μόνος, mónos, single, alone, label=none and el, πωλεῖν, pōleîn, to sell, label=none), as described by Irving Fisher, is a market with the "absence of competition", creating a situati ...
on
unit record equipment
Starting at the end of the nineteenth century, well before the advent of electronic computers, data processing was performed using electromechanical machines collectively referred to as unit record equipment, electric accounting machines (EAM) o ...
and related
punched card
A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...
machinery, and expanding the product line into automatic typewriters equipped with paper tape raised
antitrust
Competition law is the field of law that promotes or seeks to maintain market competition by regulating anti-competitive conduct by companies. Competition law is implemented through public and private enforcement. It is also known as antitrust l ...
issues. As a result, IBM sold the product line and factory to the Commercial Controls Corporation (CCC) of
Rochester, New York
Rochester () is a City (New York), city in the U.S. state of New York (state), New York, the county seat, seat of Monroe County, New York, Monroe County, and the fourth-most populous in the state after New York City, Buffalo, New York, Buffalo, ...
, which also absorbed the National Postal Meter Corporation. CCC was formed by several former IBM employees.
World War II
Around the time of
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
, CCC developed a
proportional spacing
A typeface (or font family) is the design of lettering that can include variations in size, weight (e.g. bold), slope (e.g. italic), width (e.g. condensed), and so on. Each of these variations of the typeface is a font.
There are thousands o ...
model of the Flexowriter known as The Presidential (or sometimes the President). The model name was derived from the fact that these units were used to generate the
White House
The White House is the official residence and workplace of the president of the United States. It is located at 1600 Pennsylvania Avenue NW in Washington, D.C., and has been the residence of every U.S. president since John Adams in 1800. ...
letters informing families of the deaths of service personnel in the war. CCC also manufactured other complex mechanical devices for the war effort, including
M1 carbine
The M1 carbine (formally the United States Carbine, Caliber .30, M1) is a lightweight semi-automatic carbine that was a standard firearm for the U.S. military during World War II, the Korean War and the Vietnam War. The M1 carbine was produced ...
s.
In 1944, the pioneering
Harvard Mark I
The Harvard Mark I, or IBM Automatic Sequence Controlled Calculator (ASCC), was a general-purpose electromechanical computer used in the war effort during the last part of World War II.
One of the first programs to run on the Mark I was initi ...
computer was constructed, using an Electromatic for output.
Postwar
In 1950, Edwin O. Blodgett filed a patent application on behalf of Commercial Controls Corporation for a "tape controlled typewriter." This machine used a six-level
punched paper tape
Five- and eight-hole punched paper tape
Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program loop
Punched tape or perforated paper tape is a form of data storage ...
, and was the basis for the machines CCC and Friden built over the next 15 years. This improved machine was contemporaneous with the first generation of commercial computers. Applications for Flexowriters exploded in the 1950s, covering territory in commercial printing, machine tools, computers, and many forms of office automation. This versatility was helped by Friden's willingness to engineer and build many different configurations. In the late 1950s, CCC was purchased by
Friden, a maker of electromechanical calculators, and it was under their name that the machines achieved their greatest diversity and success; applications are further detailed below.
Two tape stations allowed implementation of what was then called the
form letter
A form letter is a letter written from a template, rather than being specially composed for a specific recipient. The most general kind of form letter consists of one or more regions of boilerplate text interspersed with one or more substitution pl ...
, the combination of standard text (one tape) with varying name and address information (the other tape).
End of product line
![Flexowriter 2201 Programatic](https://upload.wikimedia.org/wikipedia/commons/9/91/Flexowriter_2201_Programatic.jpg)
Edwin Blodgett, Chief Engineer of Friden R&D, was replaced in 1964 while ill. It is unclear what effect this had on development, especially as Blodgett was apparently biased against electronics, favoring electromechanical solutions to design problems.
Friden was acquired by the
Singer Corporation
Singer Corporation is an American manufacturer of consumer sewing machines, first established as I. M. Singer & Co. in 1851 by Isaac M. Singer with New York lawyer Edward C. Clark. Best known for its sewing machines, it was renamed Singer Ma ...
in 1965. Singer had little or no understanding of the computer industry, and there was a clash of corporate culture with Friden employees.
There was a major redesign of the Flexowriter in the mid 1960s. The Model 2201 Programatic, introduced in 1965, had a sleek modern styling and 13 programmable
function key
A function key is a key on a computer or terminal keyboard that can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function ...
s. This was the first major change in appearance of Flexowriters in nearly forty years. Programming was done using a 320-contact
plugboard
A plugboard or control panel (the term used depends on the application area) is an array of jacks or sockets (often called hubs) into which patch cords can be inserted to complete an electrical circuit. Control panels are sometimes used to di ...
, and all of the logic was implemented using
relay
A relay
Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts
An automotive-style miniature relay with the dust cover taken off
A relay is an electrically operated switch ...
s. The case, although modern looking, was entirely metal, giving the machine a shipping weight of 132 pounds (60 kg). The selling price was £2900 (British pounds).
Although primarily sold as a stand-alone
word processor
A word processor (WP) is a device or computer program that provides for input, editing, formatting, and output of text, often with some additional features.
Word processor (electronic device), Early word processors were stand-alone devices ded ...
(a term not yet in use at the time), Friden also sold it with a communications option allowing it to be used as a computer terminal. Members of the 2200 family operated at 135
words per minute
Words per minute, commonly abbreviated wpm (sometimes uppercased WPM), is a measure of words processed in a minute, often used as a measurement of the speed of typing, reading or Morse code sending and receiving.
Alphanumeric entry
Since words ...
(11.3 characters per second). The family also included the 2210 and 2211, on which the function keys were replaced with a
numeric keypad
A numeric keypad, number pad, numpad, or ten key,
is the palm-sized, usually-17-key section of a standard computer keyboard, usually on the far right. It provides calculator-style efficiency for entering numbers. The idea of a 10-key nu ...
, and the 2261, using
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
instead of the proprietary eight-bit code used by other members of the 2200 family.
[G. W. A. Dummer, F. P. Thompson, J. M. Robertson]
Friden Flexowriter Data
Banking Automation Vol. 1, pages 469-481, Pergamon Press, Oxford, 1971.
The 2300 series were cosmetically similar to the 2200 series, although without the function keys or numeric keypad, with a simplified plugboard, and operating at 145 words per minute (12 characters per second).
In addition to the basic 2301, the 2302 supported the auxiliary tape readers and punches from the 2200 family. The 2304 offered
proportional spacing and a carbon ribbon mechanism, making it suitable for preparing
camera-ready
Camera-ready is a common term used in the commercial printing industry meaning that a document is, from a technical standpoint, ready to "go to press", or be printed.
History
The term camera-ready was first used in the photo offset printing ...
copy. The base price for the 2300 family was £1400 (British pounds). This would be the last hurrah for the line, with production halting in the early 1970s.
Sales and innovation declined. In the late 1960s, the market for word processing equipment was shifting to magnetic media. IBM introduced the
Magnetic Tape Selectric Typewriter
The IBM MT/ST (Magnetic Tape/Selectric Typewriter, and known in Europe as MT72) was a model of the IBM Selectric typewriter, built into its own desk, integrated with magnetic tape recording and playback facilities, located in an attached enclosur ...
(MT/ST) in 1964. In October, 1968,
Information Control Systems
Information Control Systems (founded in 1962) was a computer programming and data processing company serving clients in the Midwestern United States.
Overview
Founded in the mid 1960s, by a graduate student from the University of Michigan at a ...
introduced the Astrotype word processing system. Both of these used magnetic tape and
Selectric
The IBM Selectric typewriter was a highly successful line of electric typewriters introduced by IBM on 31 July 1961.
Instead of the "basket" of individual typebars that swung up to strike the ribbon and page in a typical typewriter of the perio ...
print mechanisms. With its fixed type font and paper-tape recording medium, the Flexowriter had difficulty competing with these machines, although some Flexowriter documentation emphasized the fact that, unlike IBM's MT/ST tapes, Flexowriter users could cut and splice paper tapes, particularly if they could recognize some of the common codes such as carriage return.
The Diablo
daisy wheel printer
Daisy wheel printing is an impact printing technology invented in 1970 by Andrew Gabor at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to pr ...
, introduced in 1969, offered comparable print quality at twice the speed. Larger manufacturers such as IBM and DEC made their own console equipment, and
video terminal
A computer terminal is an electronic or electromechanical computer hardware, hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The Teleprinter, teletype was an example of an e ...
s began to appear, displacing paper-based systems. Eventually, even the CNC machine tool industry abandoned paper tape, although this was significantly slower because of the long working life of machine tools.
Applications
Automatic typewriters
From its earliest days through to at least the mid-1960s, Flexowriters were used as automatic letter writers.
While the US White House was using them during the Second World War, in the 1960s,
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
Members of Congress
A Member of Congress (MOC) is a person who has been appointed or elected and inducted into an official body called a congress, typically to represent a particular constituency in a legislature. The term member of parliament (MP) is an equivalen ...
used Flexowriters extensively to handle enormous volumes of routine correspondence with constituents; an advantage of this method was that these letters appeared to have been individually typed by hand. These were complemented by
autopen
An autopen (or signing machine) is a device used for the automatic signing of a signature. Prominent individuals may be asked to provide their signatures many times a day, such as celebrities receiving requests for autographs, or politicians sig ...
machines which could use a pen to place a signature on letters making them appear to have been hand-signed.
Auxiliary paper-tape readers could be attached to a Flexowriter to create an early form of "
mail merge Mail merge consists of combining mail and letters and pre-addressed envelopes or mailing labels for mass mailings from a form letter.
This feature is usually employed in a word processing document which contains fixed text (which is the same in eac ...
", where a long custom-created tape containing individual addresses and salutations was merged with a closed-loop form-letter and printed on continuous-form letterhead; both tapes contained embedded "
control character
In computing and telecommunication, a control Character (computing), character or non-printing character (NPC) is a code point (a number) in a character encoding, character set, that does not represent a written symbol. They are used as in-band ...
s" to switch between readers.
Console terminals
As the unit record equipment (tabulating machine) industry matured and became the computer industry, Flexowriters were commonly used as
console terminal
A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal and ...
s for computers. Because
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
character coding had not yet been standardized, each type of computer tended to use its own system for encoding characters; Flexowriters were capable of being configured with numerous encodings particular to the computer system the machine was being used with.
Computers that used Flexowriters as consoles include:
* The Electromatic on the
Harvard Mark I
The Harvard Mark I, or IBM Automatic Sequence Controlled Calculator (ASCC), was a general-purpose electromechanical computer used in the war effort during the last part of World War II.
One of the first programs to run on the Mark I was initi ...
* The
MIT
The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the mo ...
Whirlwind I
Whirlwind I was a Cold War-era vacuum tube computer developed by the MIT Servomechanisms Laboratory for the U.S. Navy. Operational in 1951, it was among the first digital electronic computers that operated in real-time for output, and the first t ...
computer, first designed to control a flight simulator, and later becoming the basis of the
SAGE
Sage or SAGE may refer to:
Plants
* ''Salvia officinalis'', common sage, a small evergreen subshrub used as a culinary herb
** Lamiaceae, a family of flowering plants commonly known as the mint or deadnettle or sage family
** ''Salvia'', a large ...
network.
* The Lincoln Laboratory
TX-0
The TX-0, for ''Transistorized Experimental computer zero'', but affectionately referred to as tixo (pronounced "tix oh"), was an early fully transistorized computer and contained a then-huge 64 K of 18-bit words of magnetic-core memory. Constru ...
, an early experimental transistor-based minicomputer, which was to be a seminal influence on
hacker
A hacker is a person skilled in information technology who uses their technical knowledge to achieve a goal or overcome an obstacle, within a computerized system by non-standard means. Though the term ''hacker'' has become associated in popu ...
culture at MIT in the late 1950s prior to the introduction of 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 famous for being the computer most important in the creation of hacker culture at Massachusetts ...
.
* The
BMEWS
The RCA 474L Ballistic Missile Early Warning System (BMEWS, "474L System", Project 474L) was a United States Air Force Cold War early warning radar, computer, and communications system, for ballistic missile detection. The network of twelve ra ...
DIP computer,
NORAD
North American Aerospace Defense Command (NORAD ), known until March 1981 as the North American Air Defense Command, is a combined organization of the United States and Canada that provides aerospace warning, air sovereignty, and protection ...
Combat Operations Center (COC), Colorado Springs, Colo., beginning in 1960. Tape code was essentially base-32.
*
Electrodata 205.
ElectroData was purchased by the
Burroughs Corporation
The Burroughs Corporation was a major American manufacturer of business equipment. The company was founded in 1886 as the American Arithmometer Company. In 1986, it merged with Sperry UNIVAC to form Unisys. The company's history paralleled many ...
, and many later Burroughs machines also used Flexowriters
* The
Librascope LGP-30 and LGP-21
* The Packard Bell PB 250
* The SEA CAB 500
* The
ALWAC III-E
The ALWAC III-E was an early commercial vacuum-tube computer employing a rotating magnetic drum main storage unit, operational in 1955. It weighed about .
The invention of the ALWAC III-E is attributed to Axel Wenner-Gren, and the name is derived ...
* The
English Electric
N.º UIC: 9094 110 1449-3 (Takargo Rail)
The English Electric Company Limited (EE) was a British industrial manufacturer formed after the Armistice of 11 November 1918, armistice of World War I by amalgamating five businesses which, during th ...
KDF9
KDF9 was an early British 48-bit computer designed and built by English Electric (which in 1968 was merged into International Computers Limited (ICL)). The first machine came into service in 1964 and the last of 29 machines was decommissioned ...
.
The Whirlwind I deployment in 1955 is notable as it seems to have been the first
time that a typewriter-like input device was directly connected to a general-purpose electronic computer, becoming directly ancestral to today's computer keyboards.
Offline punch and printer
Flexowriters could also be used as
offline punches and printers. Programmers would type their programs on Flexowriters, which would punch the program onto paper tape. The tapes could then be loaded into computers to run the programs. Computers could then use their own punches to make paper tapes that could be used by the Flexowriters to print output. Among the computers which commonly used Flexowriters for this task was the
DEC 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 famous for being the computer most important in the creation of hacker culture at Massachusetts ...
.
Machine tools
The ability to support diverse encodings meant that adapting Flexowriters to generate the paper tapes used to drive
CNC
Numerical control (also computer numerical control, and commonly called CNC) is the automated control of machining tools (such as drills, lathes, mills, grinders, routers and 3D printers) by means of a computer. A CNC machine processes a p ...
machine tool equipment was a relatively simple affair, and many Flexowriters found homes in
machine shop
A machine shop or engineering workshop (UK) is a room, building, or company where machining, a form of subtractive manufacturing, is done. In a machine shop, machinists use machine tools and cutting tools to make parts, usually of metal or plast ...
s into the 1970s, when magnetic media displaced paper tape in the industry.
Unit record and early computing
Friden manufactured equipment which could connect their calculators to Flexowriters, printing output and performing unit record tasks such as form letters for bills, and eventually manufactured their own computers to further enhance these capabilities. These variants were sold as the Friden Computyper. Computypers were electromechanical; they had no electronics, at least in their earlier models. The calculator mechanism, inside a desk-like enclosure, was much like a Friden model STW desktop calculator, except that it had electrical input (via solenoids) and output (low-torque rotary switches on the dial shafts) .
Commercial printing
A product known as the Justowriter (or Just-O-Writer) was developed for the printing industry. It allowed typists to produce
justified text for use in typesetting. This worked by having the user type the document on a Recording unit, which placed extra codes for spacing on the paper tape. The tape was placed into a second specially adapted Flexowriter which had two paper tape reading heads; one would read the text while the other controlled the spacing of the print. Spacing codes were stored in relays inside the machine as a line of text progressed. At least some Justowriters used carbon (as opposed to ink-impregnated fabric) ribbons to produce cleaner type, suitable for mass photo-set reproduction, sometimes referred to as cold type composition.
The Line Casting Control or LCC product generated paper tapes for Linotype and
Intertype automatic typesetters. In addition to punching a tape containing the text to be typeset, it turned on a lamp easily seen by the operator to show that the text on the line being typed could be typeset—it was within justifiable range. The LCC had a four-wheel rotary
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
, and a set of gears between the carriage rack and the escapement, to permit the smallest unit of spacing at the escapement to be quite small at the carriage. The spring-tensioned tape that moved the carriage had far more tension (possibly 20 lbs?) than did a standard Flexowriter.
American Type Founders
American Type Founders (ATF) Co. was a business trust created in 1892 by the merger of 23 type foundries, representing about 85% of all type manufactured in the United States. De Vinne, Theodore Low, ''The Practice of Typography,'' Century Comp ...
produced a
phototypesetter
Phototypesetting is a method of setting type. It uses photography to make columns of type on a scroll of photographic paper.
It has been made obsolete by the popularity of the personal computer and desktop publishing (digital typesetting).
The ...
based on the Justowriter/Flexowriter platform.
Finance
There was an "accounting" model with an ultra-wide carriage and two-color ribbon for printing out wide financial reports. The Friden accounting model was called "5010 COMPUTYPER" and was capable of arithmetic functions (addition, subtraction, multiplication & division) at electronic speeds and to print the results automatically in a useful document.
Hardware
As a cutting edge device of their time, Flexowriters, especially some of the specialized types like typesetters, were quite costly. They were made for extreme durability. There were porous
sintered
Clinker nodules produced by sintering
Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction.
Sintering happens as part of a manufacturing ...
bronze bearings, many hardened steel parts, very strong springs, and a substantial AC motor to move all the parts. Most parts are made of heavy gauge steel. The housing and most removable covers were heavy
die casting
Die casting is a metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which have been machined into shape and work similarly t ...
s. While the final Singer models did make some use of plastics, even they were quite heavy compared to other electric typewriters of their time.
As a result, the platen carriage was very heavy, and when the "Carriage Return" key was pressed, the carriage moved with about of force and enough momentum to injure a careless operator. If used only as manual typewriters, and properly maintained, Flexowriters might last a century. When reproducing form letters from punched tape, the considerable speed and loud sound of the device made watching it a somewhat frightening experience.
Towards the bottom of the unit there was a large rubber roller ("power roll") that rotated continuously at a few hundred rpm. It provided power for typing as well as power-operated backspace, type basket shift, and power for engaging (and probably disengaging) the carriage return clutch.
Referring to the photo of the cam assembly (often simply called a cam; it was not meant to be disassembled), the holes in the side plates at the lower left were for the assembly's pivot rod, which was fixed to the frame. At the extreme upper left was part of a disconnectable pivot that pulled down on the typing linkage. As installed, "down" was to the right in the photo.
Referring again to the part at the upper left, the mating part had a threaded mounting for adjusting cam clearance from the power roll. The irregular "roundish" part, lower right center, was the cam itself. It rotated in the frame while in contact with the power roll. The surface of the cam in contact with the power roll had grooves for better grip. As the radius at the contact patch increased, the frame rotated clockwise to pull down on the linkage to type the character.
This particular cam assembly had a cam that rotated a full turn for each operation; it might operate the backspace, basket shift, or carriage-return clutch disengage mechanism. Cams for typing characters rotated only half a turn, the halves being identical.
Below the cam in this photo (hidden) was a spring-loaded lever that pushed against a pin on the cam. On the upper edge of the cam, as shown, was a little projection that engaged the release lever, which was at the lowest part of the image; this was an irregular shape.
When a key was pressed down, it moved the release lever and unlatched the cam for that letter; the spring-loaded lever pressing on the pin rotated the cam until it engaged the power roll. As the cam continued to turn, increasing radius rotated the cam's frame slightly (clockwise in the photo) to operate the typing linkage for that character.
As the cam continued to rotate, the spring-loaded lever pushed on the pin to move it toward home position, but if the key were still down, the cam (now out of contact with the power roll) stalled because the projection on the cam would catch on another part of the release lever. The cam stalled until the key was released. When released, the lever would catch the projection so the cam was now in home position. This resembled a simple clock
escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to ...
, and prevented repeated typing. (The "key-down" anti-repeat stop could be removed, so that fast repetitive typing could be done, but this change was difficult to undo.)
Carriage return was done by a non-stretch very durable textile tape attached to the platen advance mechanism at the left of the carriage. For a return, the tape wound up on a small reel operated from the drive system through a clutch. A cam engaged the clutch; it was disengaged by the left margin stop, perhaps directly, perhaps via another cam. A light-torque spring kept the return tape wound on the reel.
The basic mechanism looked just like an IBM electric typewriter from the late 1940s. In fact, some Flexowriter parts were identical in fit and function to the early IBM electric typewriters (those with rotary carriage escapements, a gear-driven power roll, and a governor-controlled variable speed "universal" (wound-rotor/commutator) motor).
The early IBM rotary-escapement proportional-spacing typewriters (three wheel rotary escapement, spur gear differentials) had code bars to control the amount of carriage movement for the current character. They were operated by the cams. However, the Flexowriter's mechanical encoder was a very different and far more rugged design, although still operated by the cams.
Flexowriters (at least those prior to 1969) do not have
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch e ...
s; electrical control operations were done with telephone-style (E-Class)
relay
A relay
Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts
An automotive-style miniature relay with the dust cover taken off
A relay is an electrically operated switch ...
s, and troubleshooting often involved problems with the timing on the relays. Another reader has also found that the timing settings of the various leaf switches (such as in the tape reader) are also important.
The screws used in the Flexowriter were unique, having large flat heads with a very narrow screwdriver slot and a unique thread size and pitch. This may have been a
conscious decision. Another reader found that standard 4-40UNC threads appear to fit some of the cover-attachments; internally, the headless set-screws require fluted Bristol keys, which were not commonly available in Great Britain.
There was a holder for a large roll of paper tape on the back of the unit, with tape feeding around to a punch on the left side, toward the rear. The tape reader was on the same side, toward the front, and was essentially identical to the reader shown on the front of the square housing in the photo of the auxiliary reader. The right side of a Flexowriter had a large (~1") connector for hooking the unit up to computers and other equipment. Depending on the model, this connector might be wired in many different ways.
At various times and in various configurations, "Flexos" came with 5-, 6-, 7-, or 8-channel paper tape reader/punches, could have several auxiliary paper tape units attached, and could also attach to IBM punched card equipment.
See also
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Expensive Typewriter
Expensive Typewriter was a pioneering text editor program that ran on the DEC PDP-1 computer which had been delivered to MIT in the early 1960s.
Description
Since the program could drive an IBM Selectric typewriter (a letter-quality printer), i ...
*
TECO
*
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 famous for being the computer most important in the creation of hacker culture at Massachusetts ...
References
External links
Friden Flexowriter: a part of Manuals at bitsavers.orgPhotos and historyRetrieved April 10, 2007
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ttp://www.textfiles.com/bitsavers/pdf/frieden/flexowriter/Patent_2700446_Jan55.pdf Flexowriter patentbr>
Firearms code markings including note of CCC produced M-1s.
Description of JustowriterAlso discusses Blodgett
Video of a Flexowriter SPD typing from a punched tapeComputer museum @ hack42.nl
{{Authority control
Typewriters
Word processors
Computer terminals