This article is now outdated. For now, see this DT thread for my latest info on M6/M6-1.
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Hey all!
This is my long-awaited follow-up to the IBM Model M4 article I released back in July! This one talks about the Model M3 and M6 that preceded and succeeded the M4s in the portable computer space.
This has been many months in the making and I really hope you enjoy it! I know these keyboards themselves won’t be interesting to everyone, but for the sake of documentation and presenting their mark on history, I hope you can appreciate the goal of the article at least. Especially, I wanted to figure out exactly how many IBM portables used these keyboards, and it turns out, more than I thought… and even laptops from other companies used these.
The article: https://sharktastica.co.uk/articles/m3- ... es_laptops
Deserving of thanks is everyone who helped me with supplying photos for the article! All helpers should be noted under the "Acknowledgements" section.
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In the interest of possible discussion, I'll summarise a few things here. Just note that all the evidence/detailed explanation for things will be in the article.
Model M3-based assembly (also applicable to M4/M4-1):
The original IBM buckling sleeves assembly type developed for the IBM PS/2 L40SX, named after the L40SX's numeric keypad designation for convenience. I appreciate there's a Model M2 variant also called M3, but the L40SX numpad beats the claim by several years, so... These have rod-actuated buckling sleeves switches and keyboards using this style are known to always have squarer-profile F and nav keys. The assembly was adopted for the Model M4 & M4-1 Space Saver Keyboards and later Unicomp Mighty Mouse.
- Uberman765_l40sx_keyboard.jpg (96.6 KiB) Viewed 6125 times
Model M6 assembly
The original slider-actuated variant of IBM buckling sleeves assembly. These had brown sliders that looked more 'minimalistic' than the later M6-1's sliders. These launched on the ThinkPad 700, aka, the first true ThinkPad as we now know and recognise as a "ThinkPad". These mostly did away with the squarer profile for F and nav, however, the ThinkPad 350 and PS/Note 425 (both essentially the same machine) are notable exceptions.
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Model M6-1 assembly
The revised slider-actuated variant of IBM buckling sleeves assembly. These had a black slider instead. These launched on the ThinkPad 750 and were used up until and including the RS/6000 Notebook 860. After Lexmark exited the keyboard business, Key Tronic took over production.
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M3/M4/M4-1 type switch components
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M6/M6-1 type switch components
- m6_components.jpg (461.19 KiB) Viewed 6115 times
IBM laptops using these buckling sleeves
- IBM PS/2 L40SX (M3-based)
- IBM PS/2 CL57SX (M3-based)
- IBM PS/55 Note N27sx (M3-based)
- IBM PS/Note 2141-x82 series (M3-based)
- IBM PS/55 Note T22sx (M3-based)
- IBM ThinkPad 700 series (M6)
- IBM PS/55 Note C52 (M6)
- IBM ThinkPad 720 series (M6)
- IBM ThinkPad 350 series (M6)
- IBM PS/Note 425 series (M6)
- IBM ThinkPad 500 (Presumed M6)
- IBM ThinkPad 750 series (M6-1)
- IBM PS/55 5535-ZAD (Presumed M6)
- IBM RS/6000 Notebook N40 (M6-1)
- IBM ThinkPad 360 series (M6-1)
- IBM ThinkPad 370C (M6-1)
- IBM ThinkPad 355 series (M6-1)
- IBM ThinkPad 510CS (M6-1)
- IBM ThinkPad 755C series (M6-1)
- IBM ThinkPad Power Series 850 (M6-1)
- IBM ThinkPad 365 series (M6-1)
- IBM RS/6000 Notebook 860 (M6-1)
- Lexmark Lexbook AR-10 (M3-based)
- Lexmark Lexbook GS-20 (M3-based)
- Lexmark Lexbook MB-10 (M6-based)
- Lexmark Lexbook MB-15 (M6-based)
- SAIC Galaxy 1100 (M3-based)
- Tadpole SPARCbook 3 series (M6-1 based)
- Tadpole SPARCbook 3000 series (M6-1 based)
- Tadpole P1000 series (M6-1 based)
- Tadpole ALPHAbook 1 (M6-1 based)
- Lexmark Lexbook SE-10 (M6 based)
- AST Ascentia 9x0N series (M6-1 based)
