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 with a US-style keyboard in all versions of Windows prior to Vista through the use of the AltGr key modifier. MS Windows 7 now includes the correct diacritical signs in the default Romanian Keyboard layout. This layout has the Z and Y keys mapped like in English layouts and also includes characters like the 'at' (@) and dollar ($) signs, among others. The older cedilla-version layout is still included albeit as the 'Legacy' layout. In Slovakia, similarly to the Czech Republic, both QWERTZ and QWERTY keyboard layouts are used. QWERTZ is the default keyboard layout for Slovak in Microsoft Windows.