Control-C else, typically returning control to the user. Ctrl-C was one of a handful of keyboard sequences chosen by the program designers at Xerox PARC to control text editing, with Ctrl-Z (Undo), Ctrl-X (Cut), Ctrl-V (Paste), and Ctrl-P (Print). The first four letters are all located together at the left end of the bottom row of the standard QWERTY keyboard, and P towards the upper right. The equivalent key combination on Macintosh computers is Command-C. Control-C as an abort command was popularized by TOPS-20 and TOPS-10 and adopted by other systems including Unix. It was also adopted by Digital Equipment operating
QWERTY based partly on QWERTY and is claimed to be easier for an existing QWERTY typist to learn while offering several supposed optimisations. Most modern computer operating systems support these and other alternative mappings with appropriate special mode settings, with some modern operating systems allowing the user to map their keyboard in any way they like, but few keyboards are manufactured with keys labeled according to any other standard. Comparisons have been made, between Dvorak, Colemack, QWERTY, and other keyboard input systems, namely stenotype or its electronic implementations (e.g., Plover an opensource project ). However, stenotype is a fundamentally different system,