On an Amiga this is done with Ctrl + Right Amiga + Left Amiga; on IBM PCs and many microcomputers it is Ctrl + Alt + Del; on Suns, L1 + A; on some Macintoshes, it is Cmd + Power switch. [Silicon Graphics]? users are obviously the most dextrous however, as these machines use the five-finger combination: Left Shift + Left Ctrl + Left Alt + Keypad Divide + F12.