.edge
From WikiManual
.edge (214) - reads back a value of 1 if the bot has hit the edge of the screen. Most commonly used to turn bot specified number of degrees in order for it to face away from the edge. Does not activate if torroidal mode is enabled.
Example:
314 rnd .aimdx *.edge mult store
this will turn a bot a random number of degrees (0-90 Clockwise) upon hitting an edge.
