INT E0 - PCROBOTS v1.41 - "SHOOT" - FIRE A SHELL AT ANOTHER ROBOT

	AX = 0003h
	BX = direction (0-359 degrees)
	CX = range (0-700)
Return: AX = status (0000h not fired, else ID of shell fired)
Notes:	up to seven shells may be in flight for a robot at one time; the cannon
	  takes 50 ticks to reload
	this call also terminates the current robot's turn
SeeAlso: AX=0000h,AX=0001h,AX=0002h,AX=002Ch