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 for computer keyboards, too. Czech QWERTY layout differs from QWERTZ in that the characters (e.g. @$& and others) missing from the Czech keyboard are accessible with AltGr on the same keys where they are located on an American keyboard. In Czech QWERTZ keyboard the position of these characters accessed through AltGr differs. Both the Danish and Norwegian keyboards include dedicated keys for the letters Å/å, Æ/æ and Ø/ø, but the placement is a little different, as the and keys are swapped on the Norwegian layout. (The Finnish–Swedish keyboard is also largely similar to the Norwegian layout, but the and are