Command key keyboard of the NeXT Computer that key was marked in green. The menus were not marked with a symbol denoting the command key. Besides being used as a modifier key for keyboard shortcuts it was also used to alter the function of some keys. toggles alpha lock, sends Enter and toggles Mute. The functions were printed in green on the front side of the modified keys. This was also done on the Z, X, C and V keys (Undo, Cut, Copy and Paste). On the NeXT ADB keyboard, the Command keys were replaced by keys labeled and the Command key
Membrane keyboard two layers apart. Under normal conditions, the switch (key) is open, because current cannot cross the non-conductive gap between the traces on the bottom layer. However, when the top layer is pressed down (with a finger), it makes contact with the bottom layer. The conductive traces on the underside of the top layer can then bridge the gap, allowing current to flow. The switch is now "closed", and the parent device registers a keypress. Typical applications include; Source, APEM, Membrane switch panels "QWERTY layouts unless otherwise specified" Membrane keyboard A membrane keyboard is a computer keyboard whose "keys" are not