The Sega Dreamcast (1998–2001) uses a proprietary 16-pin AV multi-connector that aggregates all video output modes into a single socket. Developed by Sega Enterprises and documented in the Dreamcast Hardware Specification Outline (September 1999), the connector carries composite video, S-Video (Y+C), analogue RGB at 15 kHz (SCART-compatible), and VGA at 31 kHz, alongside stereo audio and power rails. The output mode is selected at the hardware level via two dedicated mode-select pins (6 and 7), which are read by the HOLLY chip’s PIO interface and route signals to the appropriate cable type. The connector is unique to the Dreamcast and is not compatible with AV connectors from any other Sega console generation.
| Pin | Description |
|---|---|
| 1 | Ground |
| 2 | Right Audio |
| 3 | Left Audio |
| 4 | +12v |
| 5 | +5v |
| 6 | selects horizontal scan: Grounded = 31KHz (VGA) Floating/disconnected = 15KHz (TV) |
| 7 | selects format: Grounded = RGB; Floating/disconnected = Composite/S-Video |
| 8 | Vertical Sync (for VGA) |
| 9 | Horizontal Sync (for VGA) |
| 10 | Composite Sync |
| 11 | S-video |
| 12 | S-video |
| 13 | Composite Video |
| 14 | Blue (Use 220uf cap) |
| 15 | Green (Use 220uf cap) |
| 16 | Red (use 220uf cap) |
Notes
The connector is a proprietary 16-pin part unique to the Dreamcast; Sega did not publish a public mechanical specification for it. The four output modes are selected by the logic state of pins 6 and 7: both floating selects composite/S-Video (15 kHz); pin 7 grounded alone selects RGB/SCART (15 kHz); both pins 6 and 7 grounded selects VGA (31 kHz). The Dreamcast also has a separate DE-15 expansion port on the rear of the console that provides a direct VGA output, bypassing the 16-pin AV connector entirely. Capacitors on the RGB lines (pins 14–16) are required when connecting to SCART inputs that apply a DC bias.
Signals
- GND — signal and chassis ground (pin 1)
- Audio R — right analogue audio output
- Audio L — left analogue audio output
- +12V — 12 V DC supply rail, present on pin 4; used by some AV cable accessories
- +5V — 5 V DC supply rail, present on pin 5
- Mode Select 1 — pin 6; controls horizontal scan rate (grounded = 31 kHz VGA, floating = 15 kHz TV)
- Mode Select 2 — pin 7; controls signal format (grounded = RGB, floating = composite/S-Video)
- VSync — vertical sync, pin 8; active in VGA mode only
- HSync — horizontal sync, pin 9; active in VGA mode only
- CSync — composite sync, pin 10; used for RGB/SCART and some VGA cables
- S-Video C — S-Video chroma (colour) signal, pin 11
- S-Video Y — S-Video luma (luminance) signal, pin 12
- Composite Video — combined luminance and chrominance signal, pin 13
- Blue — analogue blue component, pin 14; DC-coupled; coupling capacitor required for SCART use
- Green — analogue green component, pin 15; DC-coupled; coupling capacitor required for SCART use
- Red — analogue red component, pin 16; DC-coupled; coupling capacitor required for SCART use