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
Dvorak Simplified Keyboard standard keyboard layout). The Dvorak pattern was designed with the belief that it would significantly increase typing speeds with respect to the QWERTY layout. Dvorak believed that there were many problems with the original QWERTY keyboard pattern such as: Dvorak studied letter frequencies and the physiology of the hand and created a new pattern to alleviate the above problems, based on the following principles: The Dvorak pattern is intended for the English language. For other European languages, letter frequencies, letter sequences, and bigrams differ from those of English. Also, many languages have letters that do not occur in English. For