IBM Model M6/M6-1 ThinkPad, PS/note & PS/2 laptop keyboard assemblies

User avatar
sharktastica

08 Aug 2023, 19:33

Anyone who has or had particularly early ThinkPads (700 to 755, 350 to 365, etc.) and taken them apart or lifted the keyboard may have noticed they have an "M6" or "M6-1" Model M designation on their manufacture sticker... The IBM Model M6 was the original family of ThinkPad keyboards used on many historical models, using IBM's own key-switch technology (IBM buckling rubber sleeves, thus related to the Model M3 IBM PS/2 L40SX keyboards/numpads and M4/M4-1 desktop keyboards) and were the first keyboards with integrated TrackPoints and the vessel that popularised the 7-row 'classic' layout ThinkPad fans are fond of. In my opinion, good keyboards in their own right and much loved by period press and current ThinkPad fans.

This is my wiki page documenting all known variations of these keyboards. A nice exercise to see how this type of keyboard developed over the '90s. Built upon my earlier article from late 2021 (that is now grossly out of date). Included are not only IBM branded ones, but various others that a former part of IBM who made most of these keyboards - Lexmark - produced for their own branded laptops and third parties. Non-IBM laptops using IBM keyboard technology!

The page: https://sharktastica.co.uk/wiki?id=modelm6

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Included are some common design specs, a discussion on M6 vs M6-1, and a description of the "types" system I came up with to describe the 6 common layout/form-factor combo lineages ...and of course, a full variants list! Some fun pixel art at the end too. This wiki page too ages to finish - like ~15k words, ~100k characters, and 110 citations! Applicable IBM portables include the PS/2 CL57SX; PS/note 182, 425; ThinkPads 350, 355, 360, 365, 370C, 500, 510, 700, 720, 750, 755C, Power Series 850; RS/6000 Notebook N40 and 860.

Enjoy!

Special thanks to the following:
  • laptop.pics - once again helped as an important collaborator, providing many photos from their collection
  • Jason Eckert - photos of the Tadpole 3000ST's keyboards
  • micrex22 - the initial inspiration and technically starting the process of highlighting M6-1 in their 2016 DT post
  • themk - for having their Discord DMs open and listening to me as I ramble on and stream my train of thought whilst writing this

User avatar
sharktastica

08 Aug 2023, 19:52

Full applicable laptop/subnotebook/portable workstation list

M6 or M6-1 is given either by IBM/Lexmark's assignment or based on a keyboard's closest related M6 or M6-1 (pretty much all the keyboards are related to at least another or based on another's layout) with the discussion in the "M6 versus M6-1" section of the page in mind. Types are given to represent layout and form-factor lineages.
  • IBM 8554 PS/2 CL57SX (1992, Type I Model M6)
  • IBM 5527 PS/55note N27sx (1992, Type I Model M6)
  • Lexmark AR10 OEM series (1992, Type II Model M6)
  • IBM 9552 ThinkPad 700 series (1992, Type III Model M6)
  • IBM 9552 PS/55 note C52 (1992, Type III Model M6)
  • IBM 2141 PS/note 182 series (1992, Type II Model M6)
  • IBM 9552 ThinkPad 720 series (1993, Type III Model M6)
  • IBM 2618 ThinkPad 350 series (1993, Type II Model M6)
  • IBM 2618 PS/note 425 series (1993, Type II Model M6)
  • IBM 2603 ThinkPad 500 series (1993, Type IV Model M6-1)
  • IBM 9545 ThinkPad 750 series (1993, Type V Model M6-1)
  • Lexmark GS20 OEM series (1993, Type II Model M6)
  • Lexmark Lexbook MB10 & MB15 (1993, Type IV Model M6-1)
  • Tadpole SPARCbook 3 series (1993, Type III Model M6-1)
  • Lexmark Lexbook SE10 (1994, Type IV Model M6-1)
  • IBM 7007 RISC System/6000 Notebook N40 (1994, Type V Model M6-1)
  • IBM 2620 ThinkPad 360 series (1994, Type V Model M6-1)
  • IBM 9545 ThinkPad 755C "early" series (1994, Type V Model M6-1)
  • Winbook XP series (1994, Type VI Model M6-1)
  • IBM 2619 ThinkPad 355 series (1994, Type V Model M6-1)
  • AST Ascentia 900N series (1994, Type VI Model M6-1)
  • IBM 2604 ThinkPad 510Cs (1994, Type IV Model M6-1)
  • IBM 9545 ThinkPad 755C "late" series (1994, Type V Model M6-1)
  • IBM 9545 ThinkPad 370C (1995, Type V Model M6-1)
  • IBM 6042 ThinkPad Power Series 850 (1995, Type V Model M6-1)
  • Tadpole P1000 series (1995, Type III Model M6-1)
  • IBM 2625 ThinkPad 365 series (1995, Type V Model M6-1)
  • Tadpole ALPHAbook 1 (1995, Type III Model M6-1)
  • IBM 7249 RS/6000 Notebook 860 (1996, Type V Model M6-1)
  • Apple Newton MessagePage Keyboard (1996, Type IV Model M6-1)
  • Tadpole SPARCbook 3000 series ([as late as] 1997, Type III Model M6-1)
Definition of types
  1. An M6 with M3-style (IBM PS/2 L40SX) 6-row layout and standardgauge buckling sleeves
  2. An M6 with M3-style keys but ThinkPad-like 7-row layout and standard or alt-standard gauge sleeves
  3. An M6 or M6-1 with true ThinkPad-style 7-row layout and standard, alt-standard and medium gauge sleeves
  4. An M6-1 with a very compacted 5/6-row layout and medium and small gauge sleeves
  5. An M6-1 with true ThinkPad-style 7-row layout, hinges to allow the keyboard to lift, and standard, alt-standard and medium gauge sleeves
  6. An M6-1 with a "normal sized" (like IV but normal unit sizes) 6-row layout with standard or small gauge sleeves
Sleeve gauges for reference

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