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 the letter Ґ, which does not exist in Russian. The other long-standing problem was the omission of the apostrophe, which is used in Ukrainian almost as commonly as in English (though with a different value), but which also does not exist in Russian. Both of these problems were resolved with the "improved Ukrainian" keyboard layout for Windows available with Vista and subsequent Windows versions. There also exists an adapted keyboard for Westerners learning Ukrainian (mostly in the diaspora) which closely matches the qwerty keyboard, so that the letters either have the same sound or same shape, for example pressing the