Interactive Connector Diagram
Click or tap any pin in the diagram below to inspect its signal assignment, electrical specification, and wire colour standard.
Supported Systems / Found On — Retro Machine Hubs
This connector is used on the following retro computer systems. Click any colour-coded badge below to open its full board-level repair, diagnostic, and schematic Machine Hub:
Connector Specifications
Full Pin Assignment & Wiring Reference
| Pin | Signal Name | Direction | Electrical Spec / Role | Wire Colour / SCART / Adapter Target |
|---|---|---|---|---|
| 1 | AUDIO OUT | Out | YM2149 Mono Audio Output (mixed with DMA sound on STE) | SCART Pins 2 & 6 (Audio L+R) |
| 2 | CVBS / CSYNC | Out | Composite Video (STFM/STE) or TTL Composite Sync (ST/STF) | SCART Pin 20 (Sync In) |
| 3 | GPO | Out | General Purpose Output from YM2149 Port A Bit 6 | NC |
| 4 | /MONO DETECT | In | Open = 15kHz Color RGB | Grounded to Pin 13 = 71.2Hz Mono! | Toggle Switch to Pin 13 (VGA Mono) |
| 5 | AUDIO IN | In | External Audio Input | NC |
| 6 | GREEN | Out | 0.7 Vpp Analog Green Video | SCART Pin 11 (Green) |
| 7 | RED | Out | 0.7 Vpp Analog Red Video | SCART Pin 15 (Red) |
| 8 | +12V DC | Pwr | +12 V DC Output ( via 470 Ω pull-up on ST motherboard) | SCART Pin 16 (RGB Blanking) & Pin 8 |
| 9 | /HSYNC | Out | TTL Horizontal Sync (15.7 kHz Color / 35.7 kHz Mono) | VGA Pin 13 (HSYNC) |
| 10 | BLUE | Out | 0.7 Vpp Analog Blue Video | SCART Pin 7 (Blue) |
| 11 | MONO VIDEO | Out | 640x400 71.2 Hz High-Res Monochrome Pixel Stream | VGA Pins 1, 2 & 3 (R+G+B tied together) |
| 12 | /VSYNC | Out | TTL Vertical Sync (50/60 Hz Color / 71.2 Hz Mono) | VGA Pin 14 (VSYNC) |
| 13 | GND (0 V) | GND | Common Video, Sync & Audio Ground (Bottom Offset Pin + Shell) | SCART Pins 4, 5, 9, 13, 17, 18, 21 |
Building a Dual-Mode Atari ST RGB SCART + 640x400 VGA Multisync Cable
Every Atari 520ST, 1040STF, 1040STFM, 1040STE, and Mega ST uses a proprietary 13-pin circular DIN monitor socket. When Pin 4 (/MONO DETECT) is left floating, the Shifter outputs 15.6/15.7 kHz Analog RGB on Pins 7 (Red), 6 (Green), and 10 (Blue) with Composite Sync on Pin 2. When Pin 4 is grounded to Pin 13 (GND), the ST reboots into crisp 640x400 71.2 Hz SM124 Monochrome mode on Pin 11 (MONO) with separate HSYNC (Pin 9) and VSYNC (Pin 12) — which many modern VGA LCD monitors sync to directly!
- 15 kHz Color RGB SCART Wiring: Wire DIN Pin 7 (Red) to SCART Pin 15, DIN Pin 6 (Green) to SCART Pin 11, DIN Pin 10 (Blue) to SCART Pin 7, DIN Pin 2 (Composite Video/Sync) to SCART Pin 20, DIN Pin 1 (Audio) to SCART Pins 2 & 6, DIN Pin 8 (+12 V) to SCART Pin 16 (via 1 kΩ resistor if needed), and DIN Pin 13 (GND) to SCART Pins 4, 5, 9, 13, 17, 18, 21. Leave Pin 4 OPEN!
- 640x400 71.2 Hz High-Res VGA Adapter (for Cubase / Notator / Calamus): Ground DIN Pin 4 (/MONO DETECT) to DIN Pin 13 (GND), wire DIN Pin 11 (MONO) to VGA Pins 1, 2, and 3 (Red+Green+Blue tied together via 47 Ω–75 Ω resistors), DIN Pin 9 to VGA Pin 13 (HSYNC), DIN Pin 12 to VGA Pin 14 (VSYNC), and DIN Pin 13 to VGA Pins 5, 6, 7, 8, 10 (GND).