The LazyBoy Library Manual - SetSwitchChar

Part of the System group.

%imacro SetSwitchChar 1
Prefers: AL

Return the character used for command line switches.

Support for changing the switch character varies between DOS versions and DOS vendors. When not supported, the Carry Flag will be set.

Even if the change reports successful and the Carry flag is clear, you should always verify the setting again by reading back the current switch character.

Example:

    SetSwitchChar AL     ; Change the command line switch character

See also GetSwitchChar