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 and 1915, Dealey attended seminars on the science of motion and later reviewed slow-motion films of typists with Dvorak. Dvorak and Dealey meticulously studied the English language, researching the most used letters and letter combinations. They also studied the physiology of the hand. The result during 1932 was the Dvorak Simplified Keyboard. During 1933, Dvorak started entering typists trained on his keyboard into the International Commercial Schools Contest, which were typing contests sponsored by typewriter manufacturers consisting of professional and amateur contests. The professional contests had typists sponsored by typewriter companies to advertise their machines. QWERTY typists became disconcerted by