mode

    mode [device][options]

Configures and sets the state for various hardware devices, and more:

LPT        Parallel Ports
COM        Serial Ports
PARK       Parks the hard drive
DELAY      Sets the keyboard auto-repeat rate
SWITCHAR   change DOS command line option switch character (usually /)

CAPSLOCK   State of the Caps lock key
NUMLOCK    State of the Num lock key
SCRLOCK    State of the SCroll lock key

For more information on using these features, go to mode.txt