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 example, the otherwise redundant right-hand key may, when available, be used for this purpose. Keyboard layouts have evolved over time, usually alongside major technology changes. Particularly influential have been: the Sholes and Glidden typewriter (1874, also known as Remington No. 1), the first commercially successful typewriter, which introduced QWERTY; its successor, the Remington No. 2 (1878), which introduced the shift key; the IBM Selectric (1961), a very influential electric typewriter, which was imitated by computer keyboards; and the IBM PC (1981), namely the Model M (1985), which is the basis for many modern keyboard layouts. Within a community, keyboard layout