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 were used inside the company and even sold commercially. The Apple IIe had a keyboard ROM that translated keystrokes into characters. The ROM contained both QWERTY and Dvorak patterns, but the QWERTY pattern was enabled by default. A modification could be made by pulling out the ROM, bending up four pins, soldering a resistor between two pins, soldering two others to a pair of wires connected to a DIP switch, which was installed in a pre-existing hole in the back of the machine, then plugging the modified ROM back in its socket. The "hack" was reversible and did no damage.