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
Dvorak Simplified Keyboard faster typing while also reducing repetitive strain injuries, although that claim is controversial. Although the Dvorak Simplified Keyboard (DSK) has failed to replace the standard QWERTY, most major modern operating systems (such as Windows, macOS, GNU/Linux, Android, Chrome OS, and BSD) allow a user to switch to the Dvorak layout. iOS does not provide a system-wide, touchscreen Dvorak keyboard, although third-party software is capable of adding the pattern to iOS, and the layout can be chosen for use with any hardware keyboard, regardless of printed layout. The Dvorak layout was designed to replace the QWERTY keyboard pattern (the "de facto"