In vim, why is 'j' used for down and 'k' for up?

Question

I\'ve been using vim for many years and have never really thought about it. A friend of mine asked why that is, noting that in our culture, left would usually map to up while ri

Answer 1

The answer is in the wikipedia entry for vi. Bill joy, who wrote the visual mode of ex - which ended up being vim precursor vi - used a Lear Siegler ADM3A terminal on which the H, J, K, L keys mapped to left, down, up, right - and its been that way ever since.

Here's the keyboard layout:

A couple of other points of note on the ADM3A layout:

• Left of the Q: the escape key - somewhat handier than where it is on keyboards today, hence a good choice for switching between normal and insert modes.
• Top right: the 'Home' key doubles as the tilde (~), which subsequently became shorthand for a Unix user's home directory.