HJKL is a layout used in the Unix computer world, a practice spawned by its use in the vi text editor. The editor was written by Bill Joy for use on an Lear-Siegler ADM-3A terminal, which places arrow symbols on these letters since, like the original Mac shown above, it did not have dedicated arrow keys on the keyboard. These correspond to the functions of the corresponding control characters Ctrl-H, Ctrl-J, Ctrl-K, and Ctrl-L when sent to the terminal, moving the cursor left, down, up, and right, respectively. [5] (The Ctrl-H and Ctrl-J functions were standard, but the interpretations of Ctrl-K and Ctrl-L were unique to the ADM-3A.) This key arrangement is often referred to as "vi keys". HJKL keys are still ubiquitous in newly developed Unix software even though today's keyboards have arrow keys. They have the advantage of letting touch-typists move the cursor without taking their fingers off of the home row. Examples of games that use HJKL are the text-based "graphic" adventures like NetHack, the Rogue series, and Linley's Dungeon Crawl. It is also used by some players of the Dance Dance Revolution clone StepMania, where HJKL corresponds directly to the order of the arrows. Gmail, Google labs' keyboard shortcuts and other websites use J and K for "next" and "previous". |