Command key

The Command key (⌘), also historically known as the Apple key, clover key,open-Apple key, splat key, pretzel key, or propeller key, is a modifier key present on Apple keyboards. The Command key's purpose is to allow the user to enter keyboard commands in applications and in the system. An "extended" Macintosh keyboard — the most common type — has two command keys, one on each side of the space bar; some compact keyboards have one only on the left.

The "⌘" symbol (the "looped square") was chosen by Susan Kare after Steve Jobs decided that the use of the Apple logo in the menu system (where the keyboard shortcuts are displayed) would be an over-use of the logo. Apple's adaptation of the symbol — encoded in Unicode (and HTML) at U+2318 ⌘ (HTML ⌘) — was derived in part from its use in Scandinavian countries to denote places of interest. The symbol is known by various other names, including "Saint John's Arms" and "Bowen knot".

Apple's computers up through the 1979 Apple II Plus did not have a command key. The first model on which it appeared was the 1980 Apple III, where there are two monochrome Apple keys, both to the left of the space bar on the lowest row of the keyboard. Two other early Apple computers, the 1982 Apple IIe and the 1984 Apple IIc, also had two such keys, one to the left and one to the right of the space bar; in these models, they mapped to the first two fire buttons of an attached joystick. This allowed for flexible combinations of a modifier key and base key (such as Open-Apple with C for Copy) with just a few extra wires and no ROM changes, since the Apple II could only register one key press at a time (Shift and Control keys were handled in the keyboard encoding hardware which generated ASCII codes). In all these cases, the left Apple key had an outlined "open" Apple logo, and the one on the right had an opaque, "closed" or "solid" Apple logo key. The Apple Lisa had only the closed Apple logo.

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