Major IBM typewriter & keyboard models

IBM referred to major encompassing designs of pre-Selectric electric typewriters and keyboards by a lettered "model". As the nomenclature was reset between typewriter and keyboard, some designations conflict such as there is a Model B Electric Typewriter and a Model B keyboard family. This topic will list and explain the known typewriter and keyboard models. As IBM also referred to its major keyboard models as "Keyboard *insert letter*", Admiral Shark's Keyboards will refer to models as either "Typewriter x" or "Keyboard x" when the context to differentiate them is not present.

Contents

Prelude (Typewriter 01)

IBM Model 01 typewriter family

Typewriter 01 (Formsholder) was IBM's first electric typewriter and the beginning of a long and successful lineage. In 1933, IBM acquired Electromatic Typewriters, Inc., renaming it to "International". Electromatic had previously worked with Remington to electrify a typewriter based on the Remington Number 12. IBM invested heavily in their new acquisition and the "improved" IBM Electric Typewriter (Model 01) was introduced in 1935^[3][3]
IBM - IBM Model 01 electric typewriter [accessed 2024-07-31]. License/note: retrieved via Wayback Machine (2023-04-03 capture).. For the duration of the "Model 01" period, the typewriters themselves could be branded "Electromatic", "International" or "IBM Electric", with the absolute latter appearing more as the years went by (from the introduction of the Executive model onwards). Several subsequent typewriter model numbers were known before IBM began using letter models, but they were all based on 01. Some would have their unique purpose printed on their front. They and their differences were:

Typewriter A

IBM Model A typewriter family

Typewriter A was the first lettered model of the IBM Electric family announced in 1948. It was a visual overhaul compared to the Electromatic-derived styling of the 01 family. It was designed for increased "conform and control" and gained a tab key^[8][8]
IBM - IBM typewriter milestones [accessed 2024-08-01]. License/note: retrieved via Wayback Machine (2023-04-03 capture).. A introduced various styling elements retained by the next two models including squarer keys and a cover hiding the mechanism under said keys. Whilst numbered models were still used (like Model 11 for the standard A), specific versions of Typewriter A (such as the toll biller and Executive versions) were now considered under one "A" umbrella in marketing.

Typewriter B

IBM Model B typewriter family

Typewriter B looked a lot like the Typewriter A it replaced in 1954, but they feature cushioned carriages, electric ribbon rewind, changeable typebars, multiple copy control, and pastel colour options from the get-go^[8][8]
IBM - IBM typewriter milestones [accessed 2024-08-01]. License/note: retrieved via Wayback Machine (2023-04-03 capture).. As before, B was available in a standard and Executive version as well as several minor variants. 1958 proved to be an important year as IBM began to utilise IBM Electric Typewriters in different roles such as the printing element of the IBM 632 Electronic Typing Calculator. The IBM 7070 Data Processing System gave the Electric a 'big break' in the form of its IBM 7150 Console Typewriter & Operating Keyboard and IBM 7900 Inquiry Station Typewriter Keyboard components, which utilised Model B typewriting components inside a form of terminal computer, kickstarting the IBM printer-keyboard family that eventually became IBM's dominant keyboard design for the '60s/Selectric era.

Typewriter C

IBM Model C typewriter family

Typewriter C was announced in 1959 and represented a new visual update over Typewriters A and B, retaining the same key design but overall resembling the IBM printer-keyboards that had used IBM Electric Typewriter assemblies previously. Over Typewriter B, C introduced 28 new features aimed at improving productivity including personal touch control, a "Quiet-Glide" carriage design providing longer writing lines and making it easier to move by hand if needed, and a new margin reset key. As before, variants included the Standard (Model C1), Hektowriter, and Executive (Model C4) models^[8][8]
IBM - IBM typewriter milestones [accessed 2024-08-01]. License/note: retrieved via Wayback Machine (2023-04-03 capture).. Typewriter C possibly served as the basis of the alphabetic-layout data entry keyboards for IBM 702 and 705 Data Processing Systems.

Typewriter D

IBM Model D typewriter family

Typewriter D was the final model of the IBM Electric family introduced in 1967, which was in fact a few years after IBM Selectric was first released. Typewriter D can be seen as mainly a visual overhaul of Typewriter C, both of which shared the same service manuals after D's launch^[13][13]
IBM - IBM Typebar Typewriter Model C & Model D Service Manual (#241-5665-1) [accessed 2024-08-01]. License/note: document archived by bitsavers.. Despite this, IBM claimed improvements included the ability to justify right-hand margins, expand or contract words, creature ligatures and spread headings. The keys are now the same double-shot (likely SAN) spherical-style caps IBM Selectric I and II family typewriters and then-future Keyboard B family used. As per usual, at least a Standard (Model D1) and an Executive (Model D4) variant were available. Unlike before, Typewriter Ds were not a typical choice for IBM printer-keyboards and similar consoles as the IBM Selectric family had now supplanted the Electric family in that role.

Keyboard A

Keyboard A is presently disputed. It's somewhat assumed to be a Micro Switch/Honeywell hall-effect keyboard such as the "Type A" IBM 3275/3277 Display Station Keyboards that debuted in 1971. When asked about it, Richard Hunter Harris (beam and buckling spring keyswitch inventor) was not sure whether it was a Micro Switch/Honeywell keyboard but at least did not question its existence as he did with Keyboard D and E^[15][15]
Deskthority - Dick Harris question/answer thread [accessed 2024-07-03]..

It's also been suggested it may also refer to IBM Elastic Diaphragm encoded keyboards such as the IBM 5475 Data Entry Keyboard Attachment and the IBM 5496 Data Recorder Keyboard. They were introduced at the end of the '60s and were IBM's first keyboard family using a named keyswitch design - the titular elastic diaphragm. The elastic diaphragm was an early multi-layer membrane assembly design that attached to a given IBM Selectric-based keyboard assembly in place of their mechanical assembly used to encode key input into typewriting.

By 1995, the IBM Basic II Keyboard was introduced, which bore the designation "Model A". It was made by Siam United Hi Tech on behalf of Lexmark, for IBM. The keyboard was a fairly unremarkable rubber dome keyboard and it's unclear why IBM reintroduced the "Model A" moniker for it.

Keyboard B

IBM Model B keyboard family

More information: IBM Model B (beam spring) keyboards

Keyboard B was a large family of keyboards exclusively using clicky IBM beam spring keyswitches. Keyboard B originated as 1972's IBM 3158 66-key Display Console Keyboard before being adopted by IBM 3275 and 3277 Display Stations as their "Type B" keyboards, displacing their original "Type A" Micro Switch/Honeywell keyboards. Afterwards, they saw widespread adoption and became flagships for IBM products in various industries and product segments, remaining internally unchallenged for the rest of the '70s. They were exclusively made by IBM. It's unclearly exactly when Keyboard B production stopped. According to IBM, several host terminals of Bs were still on the market in 1987, meaning they could be in production at least that late unless IBM maintained a surplus of keyboards and parts produced at an earlier time.

Keyboard C

Keyboard C was an unreleased metal buckling dome contact console panel as confirmed by Richard Hunter Harris^[15][15]
Deskthority - Dick Harris question/answer thread [accessed 2024-07-03].. No photos or timeline is available, and given C was unreleased, it's unlikely many (if any) photos exist.

Keyboard D

It's presently unclear what Keyboard D could be if it indeed existed. When asked about it, Richard Hunter Harris did not recall knowing what it was and believed it might not use a unique keyswitch module compared to Keyboard B if it did exist^[15][15]
Deskthority - Dick Harris question/answer thread [accessed 2024-07-03]..

Keyboard E

Keyboard E has been referred to in IBM literature but no photos or timeline is available. One such mention was in June 1982's IBM SiteLine magazine, where it is implied that it is similar in size to Keyboard B (at least in terms of thickness)^[21][21]
IBM - SiteLine June 1982 [accessed 2024-07-03]. License/note: photo excerpts used under fair dealing.. As with Keyboard D, when asked about it, Richard Hunter Harris did not recall knowing what Keyboard E was and believed it might not use a unique keyswitch module compared to Keyboard B^[15][15]
Deskthority - Dick Harris question/answer thread [accessed 2024-07-03]. (which would explain why Keyboard B and E are of similar size).

Keyboard F

IBM Model F keyboard family

More information: IBM Model F keyboards

Keyboard F was a large family of buckling spring keyboards introduced in 1981. All members of Keyboard F use clicky IBM capacitive buckling spring keyswitches (the original buckling-spring incarnation) and were flagships for IBM products in various industries and product segments. F-based keyboard assemblies were also used in the IBM Electronic Typewriter models 65, 85 and 95. They were formally supplanted by Keyboard M in 1985, but production of a select few F variants continued into the early to mid '90s. They were mostly made by IBM, though Lexmark made and refurbished some late examples.

Keyboard G

IBM Model G keyboard (IBM Model M Enhanced Keyboard)

More information: Model G as the original designation for Model M & the existence of Models 1A and 1B

Keyboard G was the original sequential designation for Keyboard M. It seems it was later repurposed to strictly designate the IBM Enhanced Keyboard amongst IBM Display Stations (315X, 316X, 3179, 3180, 319X, 347X and 348X) and thus technically a subset of M. Early Enhanced Keyboards made in the United Kingdom can refer to themselves as "G" via internal stickers, regardless of whether they were intended for terminals or IBM PCs. Only the IBM 3161 and 3164 ASCII Display Station Keyboards were designed and (initially) produced when the original meaning was in effect. Enhanced Keyboards made in the United States even from around their 1985 introduction refer to themselves as "M" on their external rear labels. Technically speaking, Keyboard Gs of the revised meaning were made by IBM (1985-1999), Lexmark (1991-1996) and Unicomp (1996-2004*).

*Unicomp still makes keyboards derived from Keyboard G/Enhanced Keyboard, but no longer for IBM.

Keyboard H

Keyboard H might be a series of Brother-made Apple PowerBook 2400c Keyboard Assemblies. The 2400c was produced by IBM Japan for Apple, and it appears they subcontracted Brother to make the keyboard assemblies for them. Some of these keyboards (excluding ones for the 240MHz Japanese-exclusive model) have been seen with an "H", "HOS", "HOS-1", "HOS-2" or "HOS-3" designation, but further research is needed and is in progress.

Keyboards I through L

No concrete evidence for Keyboards I through L exists. As explained under Keyboard M, the change from G to M seemed deliberate and purposeful; to now refer to the keyboard's core keyswitch technology (the use of a membrane assembly) instead of it being a sequential replacement to a large backlog of previous major keyboard designs. This changed the nomenclature's nature, potentially obsoleting it as all future IBM keyboards were membrane-driven. Keyboard H may exist as an isolated anomaly, but this came a considerable time after G/M was introduced. Around that time and thereafter, IBM was no longer designing its own large, elaborate keyboard families centred around a self-designed technology. IBM, like most of the PC industry at that point, started relying on ODMs and OEMs with at most mandating specific features on top of an ODM/OEM platform.

Keyboard M

IBM Model M keyboard family

More information: IBM Model M keyboards

Keyboard M is a massive family of membrane-driven keyboards intended to be flagships for IBM products in various industries and product segments. It was originally the same as Keyboard G but assumed to be redesignated so that the "Keyboard/Model" directly refers to their membrane nature, leaving "G" to be repurposed. The G/M lineage began in 1984 with the IBM Wheelwriters 3 and 5 and Quietwriter 7 keyboard assemblies. Whilst also originally clicky buckling-spring based keyboards, Keyboard M variants using quieter but still tactile IBM buckling sleeve and IBM Quiet Touch rubber dome keyswitches appeared in the 1990s. During this time, various unique subvariants differing on their exact keyswitch, use of an integrated pointing device, and even industry were introduced. Sometimes, these new variants received a number discriminator - for example, "M6" and "M6-1" notably served as the original IBM ThinkPad Keyboard with TrackPoint. Buckling spring Model M production has continued under Unicomp since 1996 and buckling sleeve Model Ms has continued under Toshiba Global Commerce Solutions since 2014. Besides those two, buckling-spring Model Ms were also made by IBM (1984-1999), Lexmark (1991-1996) and Maxi Switch (1995-1998), whereas buckling-sleeve ones were made by IBM (1991-1992), Lexmark (1991-1996), Key Tronic (1995-1999), Maxi Switch (1996-2002), XAC (2002-2011) and XSZ (2005-2014).

The following number discriminators are known:

Keyboard 1A

IBM Model 1A keyboard family (IBM Model M 122-key Converged Keyboard family)

More information: Model G as the original designation for Model M & the existence of Models 1A and 1B & Comparison & classifications of 122-key Model M Converged Keyboards

Keyboard 1A is a subset of Keyboard M, specifically their self-designed 122-key IBM Converged Keyboards for IBM Display Stations (3179, 3180, 319X, 347X and 348X). "1A" as a term was believed to be introduced specifically as a counterpart to the 'revised' Keyboard G meaning amongst IBM Display Station keyboards in general. The Model M Converged Keyboard went through 5 major design/featureset iterations with the first 3 - Types 1 through 3 - at least considered "1A" by IBM. It is presently unclear if they also considered Type 4 (PS/2 Host Connected Keyboards) as "1A", and Type 5 (POS Host Connected Keyboards) is unlikely to be since it's a Unicomp-introduced design with no IBM affiliation. Early Type 1 and 2 keyboards made in the United Kingdom can refer to themselves as "1A" via internal stickers, and additionally Type 2 keyboards made in the Netherlands may say "K1A" on their large external rear labels. Keyboard 1As were made by IBM (1985-1999), Lexmark (1991-1996) and Unicomp (1996-2004*).

*Unicomp still makes keyboards derived from Keyboard 1A, but no longer for IBM.

Keyboard 1B

IBM Model 1B keyboard

More information: Model G as the original designation for Model M & the existence of Models 1A and 1B

Keyboard 1B denotes the IBM 104-key Quiet Touch Keyboard made by Micro Switch/Honeywell for IBM Display Stations (319X, 347X and 348X) and first seen in February 1987. Unlike its 1A counterpart, "1B" is not related to the Keyboard M family but as a term still serves to indicate it is a counterpart to the 'revised' Keyboard G meaning amongst IBM Display Station keyboards in general. 1B does not include Keyboard F era 104-key Converged Keyboards despite the form-factor similarity and same physical layout. No production 1B keyboard has been found to refer to itself as such on any stickers they have.

Further reading & resources

External

Acknowledgements

Thank you to Mr. Haelscheir and shoggot of the typewriter hobby for donating a photo of their Model 01 and advising me on how to improve the IBM Electric series typewriter briefs respectively.

Sources

ASK. Admiral Shark's Keyboards original content. License/note: CC BY-NC-SA 4.0.

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