Substitute character actions than the last one can also be undone by pressing multiple times. was one of a handful of keyboard sequences chosen by the program designers at Xerox PARC to control text editing. Presumably these particular keystrokes were chosen because of their location on a standard QWERTY keyboard, since the Z (undo), X (cut), C (copy), and V (paste) keys are located together at the left end of the bottom row of the standard QWERTY keyboard. Substitute character A substitute character (␚) is a control character that is used in the place of a character that is recognized to be
Keyboard layout rest, thus having 70% of typing done in the home row (compared to 32% in QWERTY). The Dvorak Simplified Keyboard is available out-of-the-box on most operating systems, making switching through software very easy. "Hardwired" Dvorak keyboards are also available, though only from specialized hardware companies. The Colemak layout is another popular alternative to the standard QWERTY layout, offering a more familiar change for users already accustomed to the standard layout. It builds upon the QWERTY layout as a base, changing the positions of 17 keys while retaining the QWERTY positions of most non-alphabetic characters and many popular keyboard shortcuts, supposedly