Even before the NXT kit, the earlier RCX MINDSTORMS kit contained lights and a very simple motor that did not have a shaft encoder. To use these motors and lights with the NXT brick, you needed a converter cable. Because of the new Auto-ID system and digital motor control in the EV3, you are technically limited to using the brick lights. There are several solutions involving soldering and rewiring the cables with an extra resistor to allow older RCX motors, power function motors, and lights. The extra resistor would send a code to the Auto-ID system. To avoid soldering, you can use the black MINDSTORMS NXT converter cable to take the output from the EV3 and sends it to a two wire electrical signal. In the following image, you can see a LEGO light bulb from the NXT kit powered by the EV3:

Even with the NXT converter cable, you will find that legacy motors and lights will not work with the EV3 brick because the EV3 is still searching for the Auto-ID signal. To avoid soldering...