IBM Selectric typewriter

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The IBM Selectric typewriter (occasionally known as the IBM Golfball typewriter) is the electric typewriter design that brought the typewriter into the electronic age starting in 1961.

Image:IBM Selectric.jpg Instead of typebars it had a pivoting typeball that could be changed to use different fonts in the same document, resurrecting a capacity that had been pioneered by the Blickensderfer typewriter sixty years before.

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Features

The ability to change fonts, combined with the neat regular appearance of the typed page, was revolutionary and marked the beginning of desktop publishing. Later models with selective pitch and built-in correcting tape carried the trend even further. Any typist could produce a polished manuscript. By 1966, a full typesetting version with justification and proportional spacing was released.

Due to their speed (14.8 character/s), immunity to clashing typebars, and reliability, Selectric models with an RS-232 connector were also widely used as terminals for computers, replacing Teletypes.

The machine had a key lockout feature called "Stroke Storage" that smoothed out the irregular finger strokes of the typist. When a key was pressed a narrow metal tab on the corresponding interposer was pushed down into a slotted tube, called the Selector Compensator, full of ball-bearings under the keyboard. These balls were adjusted to have enough horizontal space for only one interposer tab to enter at a time. The typist could press two keys virtually simultaneously and both characters would print once each in rapid succession. Trying to press three or more keys simultaneously resulted in all the keys being blocked from their full downward travel and no characters typed. Two keys – the Spacebar and the Dash (or Minus)/Underline would repeat at full mechanism speed if held down firmly. At the end of each cycle, the active interposer was pushed forward withdrawing its tab from the Selector Compensator and allowing another interposer's tab to descend. This gave some users the impression that there was a storage buffer. (See typeahead for more information.)

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Design

The Selectric typewriter was first released in 1961 and is generally considered to be a design classic. After the Selectric II was introduced a few years later, the original design was designated the Selectric I. The Correcting Selectric II differed from the Selectric I in many respects:

  • The Selectric II was squarer at the corners, whereas the Selectric I was rounder.
  • The Selectric II had a Dual Pitch option to allow it to be switched (with a lever at the top left of the "carriage") between 10 and 12 characters per inch, whereas the Selectric I had one fixed "pitch".
  • The Selectric II had a lever (at the top left of the "carriage") (option available only on dual pitch models) that allowed characters to be shifted up to a half space to the left (for inserting a word one character longer or shorter in place of a deleted mistake), whereas the Selectric I did not.
  • The Selectric II had optional auto-correction (with the extra key at the bottom right of the keyboard), whereas the Selectric I did not. (The white or transparent correction tape was at the left of the typeball and its orange take-up spool at the right of the typeball.)
  • The Selectric II had a lever (above the right platen knob) that would allow the platen to be turned freely but return to the same vertical line whereas the Selectric I has the same feature, but with a different lever design. This feature is found on almost every typewriter, manual or electric. It can be used for typing super- or subscripts, although accurate alignment is difficult.
  • The Selectric II used a new ribbon cartridge technology consisting of wider ribbons that give more typed characters per inch because successive characters were staggered vertically on the ribbon, which incremented less than a full character position each time as a result. Ribbons came in two types: Correction Film with its associated Lift-Off tape, and Tech-3 permanent ribbon with its associated Cover-up tape. Tech-3 ribbons provided both security and long life because unlike the Correction Film ribbon, Tech-3 ribbons incremented only a fraction of the character width after being struck, and provided exceptionally high quality impressions for several characters from each spot on the one-time-use ribbon. Because characters overstrike each other on a Tech-3 ribbon several times as it moves more slowly through the cartridge it could not be removed and easily read to discover what had been typed on this typewriter, hence its higher security value. Some colored ribbons (e.g. brown) were also available.

Both Selectric I and Selectric II were available in standard, medium, and wide-carriage models and in various colors, including red and blue as well as traditional neutral colors, and both used the same typeballs, which were available in many fonts, including symbols for science and mathematics, OCR faces for scanning by computers, script, Old English, and more than a dozen ordinary alphabets. The typeballs came in two styles: Original models had a metal spring clip with two wire wings that squeezed together, later models had a fragile flip-up black plastic lever that could break off, which was later redesigned to have a substantial plastic lever that did not break. Over the years, there were several different styles for the ribbons, even in the same model Selectric, and they were not interchangeable. Selectric I models used either a cloth cartridge ribbon or a spool film ribbon. Non-correcting Selectric II models could use the earlier cloth cartridge.

In 1966, IBM released the Selectric Composer, the first desktop publishing system. The hybrid typewriter produced camera-ready justified copy using proportional fonts in a number of font sizes and styles, using the typeball. The machine required that material be typed twice. The first time was to measure the length of the line and count the spaces, recording special measurements on the right margin. The second time it was typed, the operator used the measurements to set justification for the line.

In the 1980s IBM introduced a Selectric III and several other Selectric models, some of them word processors or type-setters instead of typewriters, but by then the rest of the industry had caught up with the trend, and IBM's new models did not dominate the market the way the first Selectric had.

The Selectric III features a 96 character type element vs. the previous 88 character element.

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Elements and Fonts

Some of the interchangeable font elements available for the Selectric models included:

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Small (12-pitch) fonts

  • Elite 72
  • Auto Elite
  • Large Elite (12)
  • Prestige Elite 72
  • Prestige Elite 96*
  • Adjutant
  • Artisan
  • Contempo
  • Courier (12)
  • Courier Italic
  • Courier Italic 96*
  • Forms
  • Letter Gothic
  • Letter Gothic 96*
  • Light Italic
  • OCR
  • Olde World
  • Oriental
  • Report 96 (12)*
  • Scribe
  • Scribe 96*
  • Script
  • Symbol
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Large (10-pitch) fonts

  • Pica 72
  • Prestige Pica 72
  • Pica 96*
  • Advocate
  • Boldface
  • Bookface Academic 72
  • Business Script
  • Courier (10)
  • Courier 96 (10)
  • Bold Courier (10)
  • Delegate
  • Delegate 96*
  • Manifold
  • Orator
  • Sunshine Orator
  • Orator 96*
  • Orator Presenter
  • Report 96 (10)*
  • Title

Starred fonts were 96-character elements made for the Selectric III.

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Selectric Trivia

  • Capitalizing on the then-new Selectric typewriters, the IBM Pavilion at the 1964 New York World's Fair was a large theater shaped and styled like a very-much over-grown Selectric type element. The audience seating area was lifted up into the type element theater for the presentation.
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External links

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