For a while now I’ve always wanted to get hold of an IBM Model M Keyboard, purely to experience the tactility of the Buckling Spring switches. However, I’ve never really found one which ticked all the boxes, or wasn’t ridiculously overpriced for what it is (they fetch quite a premium still), so it was more of a ‘wish-list’ type of thing.
Recently, while having a sort out in my parents attic, I came across a box simply labeled ‘Pauls Bits & Keyboard’. I had no idea what this was, and just assumed it was some old stuff of mine which my late step-father had boxed up and put in the attic about 15 years prior, maybe more, but when I opened it I had quite a surprise. In the box, was an old BNC network switch, some cables, and something I didn’t even remember I had…
No, not the boxed Dreamcast (although I was pretty chuffed with that too) but the keyboard atop the pile.
IBM Model F/AT Keyboard (Model 6450225) from 1986. So, not only have I always had (and completely forgot I had) a Buckling Spring keyboard, but instead of it being a Model M, it was the earlier Model F!
Originally produced from 1981, the Model F keyboard was the ‘cost saving‘ successor to the Model B, or affectionately called ‘Beamspring’ keyboard. With the Model F, IBM introduced the Buckling Spring key switch, which is now widely renowned as one of the most influential and best feeling clicky switches. The Model F series of keyboards consist of a Buckling Spring over a Capacitive PCB, with the main contact of the switch being a conductive plastic ‘hammer’. In its unpressed state, the hammer would be raised and not in contact with the PCB, but as the key is pressed, the spring would ‘buckle’ causing the hammer to hit down on the PCB, thus creating the unmistakable ‘Click’.
This was also an extremely loud switch too, but there were still some models which had an electronic servo installed to give more feel and noise from keypresses, bringing a level of familiarity to those who were coming to use the Model F from previously being typists on older mechanical typewriters.
However, let’s get back to this specific Model F.
Now, as mentioned, I’ve no idea how long this had been in the attic to begin with, but it was certainly in need of a damned good clean, and I really wanted to see how the condition of this faired inside. All of the keys felt absolutely fine when being pressed, with no signs of binding or other issues, and when I did come to strip it all down, I was very surprised by the condition inside.
The ‘Rainbow Plate’ as it’s referred to, is a heat treated steel backplate.
The construction of the F/AT is pretty impressive, and is what adds to its overall weight. Although not as heavy as other Model F keyboards, this does still pack quite a bit given the solid steal backplate, and also the steel key barrel. Upon removing all of the keys, I got a better look as to how dirty this thing really is, and noticed some spots of corrosion on the switch plate itself, but given the age and where it’s been over the past 15 years, I’m certainly impressed by the condition still!
All of the springs showed no signs of corrosion or rust, and looking down the barrels, I could see no corrosion or anything worrying on the parts of the PCB or Flippers which I could see.
Another common weak spot is the internal foam, which over time degrades and just turns into a mess causing the keys to feel terrible, but also cause some issues with them either not registering or repeating. Thankfully, it looks like the foam in this isn’t too bad, but I’ll certainly want to replace it at some point in the future, as this required removal of the barrel plate which is certainly not for the faint hearted!
Now with the keyboard dismantled, it’s time to give it a good clean. Unlike other keyboards from this era, the Model F doesn’t really yellow at all, the case is a very thick ABS plastic, which even itself over time doesn’t appear to yellow like other ABS plastics. The keys themselves are also made from PBT, and have dye sublimated legends, the quality of these is unreal, and the clarity of the legends themselves is crisp and sharp. But, I want to get this keyboard cleaned up as best as can be, so with all the keys popped off, they get a good soak in some warm soapy water for a few hours, before being rinsed & dried off. Annoyingly though, there is only 1 part which seems to be yellowing, and that’s the feet for the keyboard (you can see in the following picture the change in colour).
Once the case was cleaned up (using a combination of warm soapy water with a microfibre cloth, followed by a bit of furniture polish), it was time to put it all back together. Honestly, this is one very nice looking example of the F/AT!
So what’s next? I’d like to get this thing working! I know there are many converters available, but if I’m honest, I’ve been doing some reading recently on the new RP2040 MCU released by the Raspberry Pi Foundation, and wouldn’t mind trying to write and build something myself to do it! So that’s my next part of this journey. And hopefully, I can make something which not only works with this keyboard, but could work with others!
Stay tuned!
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