The 21 Pin Scart Socket Explained - What are all those pins for?

The scart connector has been around for many years and is the main connection between most retro games consoles and computers and their television display.  The scart is widely found on european systems - US TVs lacked the socket and had to make do with composite video or internally modify the system for an RGB connection.

The scart is both an input and output connection - providing audio & video connections in both directions depending upon the device.

Scart socket diagran

Pin 1 Audio OUT Right Pin 2 Audio OUT Left
Pin 3 Audio IN Right Pin 4 Audio Ground
Pin 5 RGB Blue Ground Pin 6 Audio IN Left
Pin 7 RGB Blue Pin 8 AV Switch (+12 V)
Pin 9 RGB Green Ground Pin 10 N/A
Pin 11 RGB Green Pin 12 N/A
Pin 13 RGB Red Ground Pin 14 N/A
Pin 15 RGB Red Pin 16 RGB Blanking (1-3V)
Pin 17 Composite Video Ground Pin 18 RGB Blanking Ground
Pin 19 Composite Video OUT Pin 20 Composite Video IN
Pin 21 Shield / Ground