Apple Newton Keyboard - The time Apple turned to IBM/Lexmark for a Model M derivative

[sharktastica]

This is definitely a title I'm going to enjoy using.

Once again, I've got more buckling sleeve Model M content but with an interesting twist this time around! The Apple Newton Keyboard (model X0044) turns out is a Lexmark keyboard design and is a derivative of the IBM ThinkPad 500 and various Lexmark Lexbook (IBM Model M6/M6-1) keyboard assemblies, something that may give both Apple and ThinkPad folk the shudders.

Included is a brief tour around the keyboard, explanation and evidence of how it's related to the Model M family (via Model M6-1), comparison of two discovered revisions, and pointers on how you can convert one to USB (including pinout diagrams)!

The article: https://sharktastica.co.uk/articles/apple_model_m

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Re converting an X0044: I'll extract this part of the article for visibility and ease of further reference and finding. The X0044 is not ADB and uses a 8-pin mini-DIN connector. Thankfully, TheMK has made a port of TMK that supports this keyboard. For help with wiring, here is the plug pinout and the inner header pinout.

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Enjoy!

[Findecanor]

I read "Manufactured for IBM by Key Tronic".

The cross-shaped plunger with integrated snap is a design that I think is distinct for Key Tronic.
See this Key Tronic patent that uses it: (US5298706A).

[sharktastica]

I read "Manufactured for IBM by Key Tronic".

Yes, the example I used is a later Key Tronic M6-1 because it was the most 'photogenic' I had at the time I was taking photos for this article. Doesn't make much of a difference though since KT M6-1s use the same tooling as Lexmark ones. Same as with M4s, KT took over immediate production after Lexmark 'lexited' in April 1996.

Here's a Lexmark example I got recently. I didn't retake the photos with this one since this UK-made example is missing the "M6-1" designation I wanted for show.

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Here's what it should look like on a US-made example, I just didn't have my own example to take higher res photos of (but I've now included anyway in the article to hopefully resolve any future confusion):

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The cross-shaped plunger with integrated snap is a design that I think is distinct for Key Tronic.
See this Key Tronic patent that uses it: (US5298706A).

IMO, that patent looks to be more related to the IBM TrackWrite Keyboard that KT made for the ThinkPads 701C and 701Cs. Those match the sleeve orientation shown in that patent and use a plunger (although of a different shape). M6s and M6-1s use a barrel fixed slider instead with the keycap having a small crosspoint mount. That said, I can't find any specific patents that match these designs but then again I can't find any for the earlier version the M3 had (and the M4s also used) that predate both of these designs (would have been circa 1990).

[LambdaCore]

You know, I don't think I've ever heard of a buckling sleeve keyboard before, are they any good/worth looking into?

[Muirium]

So, you are still a bit wet around the ears then!

search.php?keywords=Buckling+sleeve+&te ... mit=Search

To be fair, I’ve never tried a buckling rubber sleeve keyboard either. Given my fondness for oneness with cup rubber on the one hand (Topre, Topre über alles) and buckling spring on the other (IBM supremacy!), you might think they’d be my cup of tea. I somehow doubt it! Is nominative determinism truly so real?

Anyone care trying to talk me into it? They do come in dyesub and compact layouts, right?

[LambdaCore]

That's true, only started seeking out better keyboards a year or two ago when I got my unicomp model M and went on from there. So far out of everything I've tried, I've preferred the tactile switches for what it's worth!;

[sharktastica]

You know, I don't think I've ever heard of a buckling sleeve keyboard before, are they any good/worth looking into?

To be fair, I’ve never tried a buckling rubber sleeve keyboard either.

Anyone care trying to talk me into it?

As with anything, depends on the implementation. I believe IBM buckling sleeves are rather good but there's certainly a spectrum. Generally, the main pro of a switch design using buckling sleeve is that the rubber component is divorced from direct actuation. When done right, this can avoid the bottom-out mushiness associated with your average rubber dome. The main thing to keep in mind though is key travel since IBM (and Alps) implementations are intended for portable computers - if you're fine with short-throw Topre, you should be fine with these. Generally, there's two types of sleeves; outwards expanding conical sleeves and more conservative dome-shaped sleeves.

Outwardly expanding examples:
* IBM: what this Newton Keyboard and the IBM Models M3, M4, M4-1, M6, M6-1, M7, M8, M9, M11, and "M-e" modular POS keyboards use. IBM sleeve switches actuate when a rod on the keycap or a barrel-fixed slider hits the membrane, and the sleeves are sculpted so that the rubber at the top buckles to rest aside the bottom rubber instead of all squishing at the bottom. Both allowing for a solid bottom out experience. These are my favourite sleeves I've tried so far.

* Mitsumi hybrids KKQ/KPQ: probably what people are most familiar with but perhaps unfortunately not the best representative. The sleeves themselves look like IBM's and from I've heard are fine, but the conductive rubber foot on the bottom of the their barrel sliders adds the mush back into the design from what I've been told.

* Alps: used on maybe a few Apple portables such as the PowerBook 5300cs and the IBM KeyPad III. Their sleeves are generally smaller than IBM and I find them to be less tactile, feel noticeably worse if you press a key off-centre, and the keycaps themselves are prone to wobbling to a severe degree.

Dome-shaped examples:
* KT tactile F&F: the overall feeling may be subject (eclipsed) to the condition of the foam. I have a NOS example (IBM 4683 Matrix Keyboard) and I didn't think it was that bad.

* KT sleeves for IBM TrackWrite Keyboard: what I alluded to in my reply to Findecanor. Despite the 701C/701Cs' cool novelty of the 'butterfly' keyboard, I think most people agree the sleeves don't hold up well. Examples I've tried were gummy. I'm not 100% if they were always like that, but it's interesting that IBM's own ones seem to hold up much better.

[sharktastica]

They do come in dyesub and compact layouts, right?

Pretty much all biege IBM buckling sleeve keyboards pre 2002 seem to be PBT dye-subs. The Models M3 and M4s certainly are, and the Models M7, M8, M9 and M11 POS keyboards made by Lexmark and Maxi Switch were too. However, after 2002, IBM changed OEMs for their POS keyboards that changed to lasered and pad-printed legends.

Here's a close-up of my M3 keypad's legends:

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In terms of compact layout, that'd be the Model M4/M4-1. It's a compressed tenkeyless design (compressed since the inner keyboard assembly was originally the Model M3 fitted on the IBM PS/2 L40SX and CL57SX).

[LambdaCore]

You know, I don't think I've ever heard of a buckling sleeve keyboard before, are they any good/worth looking into?

To be fair, I’ve never tried a buckling rubber sleeve keyboard either.

Anyone care trying to talk me into it?

As with anything, depends on the implementation. I believe IBM buckling sleeves are rather good but there's certainly a spectrum. Generally, the main pro of a switch design using buckling sleeve is that the rubber component is divorced from direct actuation. When done right, this can avoid the bottom-out mushiness associated with your average rubber dome. The main thing to keep in mind though is key travel since IBM (and Alps) implementations are intended for portable computers - if you're fine with short-throw Topre, you should be fine with these. Generally, there's two types of sleeves; outwards expanding conical sleeves and more conservative dome-shaped sleeves.

Interesting, if I find one on the cheap I might go for an IBM buckling sleeve, though I'll take it's probably worse than most decent mechanical switches out there from the sounds of things.

[sharktastica]

Interesting, if I find one on the cheap I might go for an IBM buckling sleeve, though I'll take it's probably worse than most decent mechanical switches out there from the sounds of things.

"Worse" is subjective. I personally prefer using them to Cherry MX tactiles and most clones of and even some Alps switches. Granted they don't have as much travel as either (although ~3mm is not far off from most Alps' ~3.5), but they have a specific tactility and snappiness I like.

[LambdaCore]

That's fair, right now I'm only now trying out Salmon Alps and utterly loving it, I also really liked 2nd gen SMKs and White Alps, based on those you think I'd like em?

[sharktastica]

Hard to say, they're just too dissimilar. I like them because they're not like other designs (except maybe short-throw Topre) if that makes sense. To be honest, it's best just to try it yourself. IBM or Toshiba CANPOS keyboards can be found cheaply on eBay and are usually the easiest way to try the switches. If you don't like them, you'd probably still be able to resell it as well.

[themk]

Hey thanks for the shout out! If anyone has any further questions about the converter I'm happy to answer.

With regards to trying IBM Buckling Sleeves, I definitely think they are worth a try. While it's certainly not the same experience as buckling spring, of course, it is a nice snappy tactile switch that works well in the keyboards it's in.