PC203 Power Controller [#3466] was used with the PC201 card to control power to the PC. This controller had four AC power sockets for plugging in the computer and peripherals. A signal line from the PC201 card controlled a relay, which supplied power to the AC sockets. A 12 Vac transformer inside of the PC203 provided power and a 50 or 60 Hz signal to the PC201 card. This allowed the PC201 card to keep time and control power regardless of the state of the PC's power.