- Published 15 April 2022
- Updated 16 April 2022
- Est. Reading Time: ~16-20 minutes
Yeah... this is definitely a title I'm going to enjoy using! Ever since the release of my last article on the Models M3, M6 and M6-1, I've been increasingly more vigilant in searching for other keyboards both IBM and third-party that use the buckling sleeve key-switches I've come to enjoy. Whilst I haven't made much progress in the five-ish months since that article was published, I've at least made one big discovery. An Apple keyboard with IBM buckling rubber sleeves that's essentially a Model M6-1 ThinkPad keyboard in disguise.
The journey of this discovery stretches back to the 2nd July 2021, a day before I published my seminal Model M4 story article. During email correspondence, Jack @ laptop.pics (who has contributed to two Admiral Shark's Keyboards articles now) raised the possibility that his Apple Newton MessagePage Keyboard felt almost like it was buckling sleeve. Whilst I didn't research into this then, the idea persisted in my mind in the following months. I didn't have any evidence during the M3/M6/M6-1 article so it wasn't included in that article either. But, now we've got somewhere.
The Apple Newton itself is an interesting device. Released in 1993 it was quite ahead of its time but let down by its "high price and early problems with its handwriting recognition feature" and eventually axed by Steve Jobs upon his return to Apple. Perhaps due to the latter issue, Apple made this dedicated keyboard (model X0044) available in early 1996 upon the release of Newton OS 2.0.
Note: I highly recommend you also read the first two sections of my Revealed: IBM Model M3 & M6 laptop buckling sleeves keyboards article either before or after as well. It may help explain why I believe this keyboard's connection to those keyboards is both cool and, in my opinion, special.
Tour around the keyboard
Starting with the case, we have a fairly functionally styled keyboard and I quite like its charm. The colour is a bit difficult to define since I found it contrasts very differently with various backgrounds and comparison objects. Generally, it ranges from a slight blue tint to a slight green tint. Taking a colour sample, iColorpalette calls it "dark slate" (#495555, RGB(73, 85, 85)). Anyway, I've tried my best to make sure my photos of this keyboard reflect this in this article but I can't guarantee it. The keyboard is also very small, small for even a 60%: 264mm x 103mm x 27mm (see full specifications table for imperial conversions). The reason for this is explained later.
Opening up the keyboard I, unfortunately, found that the inner keyboard assembly is retained by plastic clips from all sides and that most at the bottom of the keyboard had snapped. Indeed, the keyboard flexes when pressing keys on the bottom row. In lieu of a more permanent solution, I'm using sellotaped rolls of paper as padding to support the keyboard assembly. Also of note is that the bottom case piece has "ABS" embossed into it, indicating the case material. There is also a very much IBM/Lexmark esque part number (1404795) embossed just below "ABS".
After noticing and dealing with the broken plastic, I found myself amused at the fact a zip tie is being used as a cable retainer. Funny indeed, but it clearly does the job. Last thing to note is the plug, which is an 8-pin mini-DIN. We'll come back to that later.
Relation to the M6-1
Okay, so I mentioned a relationship to the Model M. The Model M family of keyboards is extremely diverse, and contrary to popular belief does not solely include buckling spring keyboards. A significant chunk of the family use buckling rubber sleeve key-switches such as the Models M3, M4, M4-1, M6, M6-1, M7, M8, M9, M11 and M-e (Model M POS extended family). Where the X0044 ties in is the M6-1.
The Model M6-1 was IBM's designation for most of their laptop keyboards from 1993 to 1996, introduced with the IBM ThinkPad 750C series and last seen with the RS/6000 Notebook 860. Whilst they were introduced by Lexmark, Key Tronic had taken over their production by Q1 1996, ahead of Lexmark exiting keyboard production in April 1996. Presumely due to their 1996 Q1 introduction, most X0044s were probably made by Key Tronic in Mexico despite being a Lexmark design. Anyway, M6s typically feature what's considered the classic ThinkPad layout that's essentially a compressed tenkeyless layout, along with a TrackPoint II or III pointing stick and two mouse buttons. The X0044 is not quite this, but a lot of M6-1 DNA is apparent. Taking logic explained in the M3/M6/M6-1 article:
- The X0044 has a metal backplate on its inner assembly that features very specific teeth-like riveting that holds the assembly together. This generally confirms the keyboard is some form of derivative of the IBM Personal System/2 L40SX keyboard assembly (aka, the Model M3).
- The keycaps mount using a crosspoint, which further refines the keyboard to belonging to either the Model M6 or M6-1. Models M3, M4 and M4-1 use a more convoluted keycap mount and a different actuator for the membrane (keycap rod actuation versus barrel slider actuation, for M3/M4/M4-1 and M6/M6-1 respectively).
- The barrel slider is black and has a solidified mounting socket, which firmly indicates it's an M6-1. M6s almost always had a brown slider with a more 'skeletal' mounting socket. Although some M6-1s could have a black 'skeletal' socket, that was just a nuance within M6-1 and no M6 had a solidified-socket black slider.
Now that the relationship has been established and proven, there are some notable differences in the design to discuss. The most obvious one is the fact the keys are physically smaller than typical M6/M6-1 (and M3/M4/M4-1) keys. The X0044's single-unit keys measure 16mm x 16mm x 3mm (excluding the crosspoint stem) compared to 18mm x 18mm x 3.8mm for a typical IBM M6-1, allowing the keyboard to be overall smaller than most other 60% keyboards. Due to this, the sleeves also need to be slightly smaller and they indeed use the same slightly smaller sleeves IBM M6s and M6-1s generally use for their function, navigation and escape keys - the medium gauge sleeve. As such, the X0044's key-travel is limited to 2.5mm versus 3mm for most IBM buckling sleeve standard keys. This may sound bad, but 2.5mm key-travel is still more than most laptop keyboards today.
However, this doesn't mean the X0044 is alone in the M6/M6-1 family with these specs. Key parts of the X0044 such as its first four key row layout and the enlarged up-arrow key in the bottom right reminded me of something... the Lexmark Lexbook MB-10, MB-15 and SE-10 Model M6 keyboards. These keyboards also use medium gauge sleeves and keycaps with a circular sleeve alignment support structure like the X0044. The Lexbooks have a mouse key in the bottom-right, but notice that the mouse key plus the padding around it matches that of the X0044's up-arrow key.
The next interesting observation is that a cutout for a pointing stick module is present on the X0044's barrel plate below the G, H and B keys. I'm unsure if Apple ever truly considered adding a pointing stick to the keyboard, but as explained in the M3/M6/M6-1 article the aforementioned Lexbooks are siblings to the ThinkPad 500 and 510CS. My logic is that if the X0044 is a retrofitted MB-1x/SE-10 keyboard, and the MB-1x and SE-10 are siblings to the ThinkPads 500 and 510CS, any quirks in shared tooling should also apply to this!
It's also worth noting that like all other M6s, all the multi-unit keys are wire stabilised and they all seem to work well. They don't seem to rattle noticably, but if you think so, it's nothing that white lithium grease (etc.) couldn't fix. However, the X0044 has a prominent grounding cable that most M6s lack.
|Outer case||264mm x 103mm x 27mm (~10.4" x 4.05" x 1.06")|
|Inner assembly||245mm x 85mm x 0.4mm (~9.7" x 3.35" x 0.016")|
|Controller PCB||122.7mm x 32mm x 1.6mm (~4.8" x 1.26" x 0.06")|
|Cable (KB to plug tip)||48cm (~1.57')|
|Keycap||16mm x 16mm x 3mm (~0.63" x 0.63" x 0.12")|
One thing that one may also be curious about is whether there was any variance or revision for the keyboard during its lifecycle, so I ended up buying two X0044s to try my luck with. And thankfully, it paid off! Let's explore the differences I found, but first, let's clarify the two keyboards:
- Keyboard A: serial # MQ5510026L5A, IC # 1F15BLLAF9534, UK English version (note: all photos of the X0044 in previous sections are of this example).
- Keyboard B: serial # PK7172HF6L5A, IC # 1F15BCTCTAA9715, US English version.
Note the four last digits of the IC number; it looks like a year and week code. Whilst I'm not 100% certain of this, from what I've seen of other X0044 examples this makes sense since ones with post 95xx numbers seem to have the revisions I found but 95xx examples do not. Anyway, let me introduce you to Keyboard B. Outwardly and keyboard assembly wise, it looks like nothing has changed.
Thankfully, the plastic assembly retainers haven't broken with this example and the reason why seems clear... It seems two plus-shaped protrusions were added just below the PCB area that helps support the assembly by preventing it from flexing down. This flex is what probably destroyed the plastic retainers in Keyboard A. To stop Keyboard A from flexing as mentioned before, I've taped some folded cardboard and paper to the bottom cover as a stopgap (and easily reversible) solution in lieu of designing a more elegant one. I could probably 3D print something to help, but I'm just waiting to find time to model something robust enough for it.
The next change is on the keycaps. It seems the printing method was changed or updated during the keyboard's lifecycle. Keyboard A's legends are clearly pad printed and have a visible outline extended outwards from the text itself. Keyboard B's legends lack this and it looks like it may be possibly silk-screened but I can't say for sure since I don't have a microscope or good enough camera to examine properly. Either way, the change is visible.
Getting it running
The X0044 does not use ADB protocol or connector like other Apple keyboards of the period, instead, it uses a unique protocol via an 8-pin mini-DIN plug - the same physical plug used for Macintosh LocalTalk. However, this had already been figured out and people have long devised ways of converting these keyboards to work on other systems:
Fellow /r/ModelM patron TheMK has also recently developed a TMK port for the X0044, which is what I'm currently running on a Pro Micro microcontroller. It so far works perfectly, effectively allowing the X0044 to be the only Model M6-1 that can be easily converted. This is the personalised layout I'm using:
Basically, a sort of 'UK English take' on ANSI. All the blank keys on the Fn layer diagram are "transparent", meaning they do the default layer function regardless of using Fn. Anyway, here are some pinout diagrams to help you with your own conversion projects:
|Function||Socket pin||Header pin||Wire colour||Microcontroller|
|DATA||8||3||Green||PD2 (typically denoted as RX1)|
Living with it
It was only fitting that I wrote pretty much all of this article using the two X0044s, so I've gotten pretty familiar with it over the two months or so I've owned Keyboard A. Since it uses IBM buckling sleeves, I knew I'd probably like this keyboard before I even touched it and indeed I do. But, it's definitely the weaker keyboard amongst my collection of Model M3s, M4s and M6s. The key-travel is of course a bit shorter meaning the keyboard feels a bit more 'binary', but not by much since it's only a 0.5mm difference. Key-feel alone, it's still fine and sports the characteristic snappiness feeling, delicious sound, and lack of mush due to the fundamental differences between sleeves and rubber domes. However, its keys are a bit more prone to binding than my other IBM buckling sleeve keyboards. It's certainly not a critical issue in my opinion, but I've definitely felt this issue at some point during usage and should be noted if you've used an M3 to M6-1 before and you're not expecting this.
I guess it may be a side effect of the scaling down of the sleeve and keycap size. The smaller sleeve probably has a harder time stabilising the keycap. For rubber domes, this issue led to the use of scissor-switches on most laptop keyboards (ie, every key gets its own stabiliser to offset how small the rubber dome is). Theoretically, IBM or Lexmark could have stabilised every buckling sleeve key in a similar manner too. But the fact the sleeve itself is usually the key's stabilising element was probably a reason sleeves were used in the first place, thus a sleeve so small that it needs its own stabiliser would defeat one of the reasons for their utilisation. This is probably why IBM gave up on buckling sleeves for portable computer keyboard assemblies after 1996 - they may have seen which way the wind was blowing (laptops were going to get thinner and thinner) thus they jumped ship to use the same tech the industry was moving towards and still uses today. My theory anyway, I haven't found any official text or narrative on IBM's rationale for laptop key-switches.
As far as real annoyances go, the only one I had was the arrow keys. I appreciate that Apple users would have been used to the various forms of arrow keys Apple had implemented on their keyboard designs of the 1980s, but I had a difficult time adjusting. I like to use arrow keys a lot so the idea of moving them to the Fn layer (say perhaps across WASD) wasn't something I was frilled about. That said, one possible solution for this could be to use the / key (on UK and US English layouts) as the up-arrow key and then position the rest below it to form a traditional inverted-T arrow key cluster, but I was worried about throwing off my muscle memory for / key. In the end, I just had to deal with it and just appreciate the fact that this is still an overall cool 60% compact IBM buckling sleeves keyboard.
This keyboard is a very interesting piece of history even when you exclude the fact it's intended for such an interesting device as the Apple Newton. It's another taste of the Apple and IBM worlds colliding in the mid-1990s, something that probably could have never been imagined just a decade before. Other examples of this 'overspill' include the fact IBM was the OEM behind the PowerBook 2400c (although that doesn't use an IBM sourced keyboard design) and of course Apple's use of PowerPC processors from 1994 to 2006. Another example of how company-to-company relationships are not clear cut.
For me in particular, this has been another interesting case study into how far the Model M family of keyboards actually penetrated the computing world. I usually use IBM's 1993 and onwards point of sale keyboards as the example of Model Ms in unexpected places, but this one is far cooler to think about! Anyway, I hope you learned something and enjoyed the read - cheers!
- Jack @ laptop.pics for making me aware of the X0044's possible buckling sleeve connection in the first place and providing photos of the Lexmark Lexbook MB-10.
- TheMK#1822 for implementing X0044 compatibility into TMK and for bouncing ideas back and forth throughout the entire writing process.