They call IBM keyboards "clicky" for a reason: With every keystroke, the keys produce a satisfying click-thunk-click via a patented mechanism called the "buckling-spring actuator." Every key press compresses the key spring until it suddenly snaps against the side of a black plastic cylinder (seen here), producing the "click" sound. Meanwhile, the spring, thus compressed, pushes a tiny pivoting rocker beneath each key that registers the key press on a membrane below.
So you KNOW when you've pressed a key. The Trackpoint never took off as much as the basic track pad, which is a shame because it's really superior, IMO. You don't have to move your hand from the keyboard area, and you don't have to keep scraping your finger across it to keep scrolling or anything. Wonderful little device. Completely confuses anyone who tries to use my computer though.
I always thought the keyboard got short shrift as fas as component manufacturers were concerned. Seems to be the last thing they think of and then just toss in some cheap off-the-shelf thing. When you think about it, second only to the screen it's the item you really interact with most often. I learned that when I almost bought a cheap laptop mail order, but thankfully checked one out at a store before I bought it. The keyboard was so flimsy you could feel the whole board area depress when you hit a key. Soft, squishy, and entirely not something you'd like to type at for very long. My Toshibas have traditionally had great keyboards, except this latest one which stinks. Feels okay, but I'm constantly hitting keys only not having them register.
They still make something like these although I haven't had to get a new one in years. At least I think they still make them similar to the original clicker. I think I may replace my current laptop with a desktop unit next, so I may have to go look for one. Hopefully, however, my trusty work keyboard will keep going strong for several more years.