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
Keyboard layout keys (this however includes more processing from the keyboard hardware, and can therefore be slightly slower, with a lag that may be noticed in daily use). A few companies offer "ABC" (alphabetical) layout keyboards. Some keyboard layouts for non-Latin alphabetic scripts, most notably the Greek layout, are based on the QWERTY layout, in that glyphs are assigned as far as possible to keys that bear similar-sounding or appearing glyphs in QWERTY. This saves learning time for those familiar with QWERTY, and eases entry of Latin characters (with QWERTY) as well for Greek users. This is not a general rule, and