ED-4, a slicer droid, functioned as one of the three droid brains that collectively formed the computer system of the starship Millennium Falcon. V5-T and L3-37 were the designations of the other two droids. The consciousness of this droid was transferred to the Millennium Falcon to work alongside V5-T, the initial droid to be integrated into the ship, well before Lando Calrissian or L3-37 had any familiarity with the Millennium Falcon.