In the ST-506 interface, the drive connects to a controller card with two ribbon cables carrying signals, while a third cable provides power. The two signal cables are the wide 34-pin control cable and the narrow 20-pin data cable. The control cable interface is very similar to the standard Shugart floppy disk interface; like that floppy disk interface, it can support four drives. The data cable carries two (Read, Write) separa.