My grandfather worked for IBM starting in 1979 till the mid 2000's. Towards the finale of his career, he worked from home, so a lot of IBM hardware ended up accumulating in his home office. One day, years after he retired, I was going through the closet and I saw a bit of beautiful beige sticking out from under a pile of other useless keyboards. A 1987 IBM Model M. I nearly had a heart attack. It was in perfect condition and only needed a bit of dusting. It has been my primary keyboard ever since, no modern mechanical has come anywhere close to matching it for me. The noise drives my coworkers absolutely bonkers though.
Wow! This was way more involved than I expected, and a super interesting read.
I did get confused near the end, when the author began speaking about "total force". The author states:
> Total Force (gfmm) is the area under the press force curve from 0 mm to bottom out
And
> The term Actuation Force is often incorrectly used for Force at Actuation (63 gf below). As Actuation Force really means how much force did it require in order to activate the switch (gfmm). So, just like Total Force we take the area under the force curve, but from 0 mm to actuation point
It seems to me that the author is measuring work (i.e. the integral of force over distance). Seems like it would be easier to understand if terms like "total work" and "actuation work" or "actuation energy" were used instead. To define "actuation force" in a way where actuation force != force at actuation strikes me as bizarre.
I still have two Model M's. (they were three but one died in an accident).
Not an advertisement or an endorsement but these guys here still manage to provide them (at a dear price, but hey, they are original refurbished Model M's):
http://clickykeyboards.com/
If you liked the original IBM "clickey" Buckling spring keyboard, you can still get something very similar from Unicomp [1]. I have one and I love it because it has such a gradual force increase as you press the key. My fingers don't "bottom out" like they do on cheap keyboards. After many years of writing a lot of code I started to develop some minor pain in my fingers from using cheap keyboards every day. When I switched to this keyboard my problems gradually subsided.
