14 pin Apple video connector.
The Apple Video Composite Out connector is a 14-pin proprietary interface found on the iMac G5, iBook G4, 12-inch PowerBook G4, and eMac. It serves as a multi-mode analogue video output: the host computer detects the type of adapter plugged in and programs the graphics integrated circuit to route the appropriate signal set to the connector. In composite mode, a standard composite video signal is present on pin 9; when an S-Video adapter is attached instead, luminance (Y) appears on pin 7 and chrominance (C) on pin 5. The connector also carries Display Data Channel (DDC) lines on pins 10 and 11, allowing the host to query a connected display for its capabilities.
| Pin | Signal |
|---|---|
| 1 | Ground |
| 2 | n.c. |
| 3 | n.c. |
| 4 | Ground |
| 5 | S-video C |
| 6 | Ground |
| 7 | S-video Y |
| 8 | +5 volts |
| 9 | Composite video |
| 10 | DDC data |
| 11 | DDC clock |
| 12 | Ground |
| 13 | Ground (for /Cable Detect) |
| 14 | Ground |
Signals
- Ground — signal return and chassis reference; pins 1, 4, 6, 12, 13, and 14 are all ground.
- n.c. — not connected; pins 2 and 3 carry no signal.
- S-video C — chrominance component of S-Video output (pin 5); active when an S-Video adapter is detected.
- S-video Y — luminance component of S-Video output (pin 7); active when an S-Video adapter is detected.
- +5 volts — 5 V supply on pin 8, used by the adapter dongle for adapter-type detection circuitry.
- Composite video — standard analogue composite video signal (pin 9); active when a composite adapter is detected.
- DDC data — I²C data line for Display Data Channel communication (pin 10), allowing the host to read the display’s EDID or capability information.
- DDC clock — I²C clock line for Display Data Channel communication (pin 11).
- Ground (for /Cable Detect) — pin 13 ground is used by the adapter as a cable-present detect signal; grounding this pin by the adapter signals the host that a video cable is attached.
Notes
- The connector is physically proprietary; a passive dongle/adapter is required to break out composite video (RCA), S-Video (4-pin mini-DIN), or VGA signals.
- The host graphics IC selects the active signal mode (composite or S-Video) based on the resistance or grounding pattern presented by the attached adapter, not by software selection alone.
- Composite video output follows standard analogue levels (approximately 1 V peak-to-peak into 75 Ω) consistent with the RCA composite convention used on Apple AV products of the same era, where the signal appears on the centre pin of an RCA connector and the outer shield is ground.
- S-Video Y and C signals on pins 7 and 5 follow the same luminance/chrominance separation used on Apple’s 7-pin mini-DIN S-Video connectors found on Power Macintosh AV models.
- DDC lines (pins 10–11) operate at 3.3 V or 5 V I²C levels; do not drive them with 5 V logic if the display only tolerates 3.3 V.