Interactive Connector Diagram
Click or tap any pin in the diagram below to inspect its signal assignment, electrical specification, and wire colour standard.
Click any pin to view its signal assignment, electrical spec, and wire colour.
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
Connector Type
9-Pin D-Sub Female (DE-9F) on rear of C128 / C128D
Color Mode
Digital 5 V TTL Red, Green, Blue, Intensity (16 colours, 15.7 kHz)
Monochrome Pin
Pin 7 outputs 1 Vpp 80-column Monochrome Composite + Sync!
Best Upscaler
RGBtoHDMI (CPLD RGBI board) or CGA2RGBv2 -> OSSC / RetroTINK
Full Pin Assignment & Wiring Reference
| Pin | Signal Name | Direction | Electrical Spec / Role | Wire Colour / SCART / Adapter Target |
|---|---|---|---|---|
| 1 | GND | GND | 0 V Primary Ground Shield | Black (RCA / DB9 Shield) |
| 2 | GND | GND | 0 V Secondary Ground Return | Black |
| 3 | RED (TTL) | Out | 5 V Digital TTL Red (from 8563 Pin 42) | Red (CGA / RGBtoHDMI) |
| 4 | GREEN (TTL) | Out | 5 V Digital TTL Green (from 8563 Pin 43) | Green (CGA / RGBtoHDMI) |
| 5 | BLUE (TTL) | Out | 5 V Digital TTL Blue (from 8563 Pin 44) | Blue (CGA / RGBtoHDMI) |
| 6 | INTENSITY (TTL) | Out | 5 V Digital TTL Brightness bit (from 8563 Pin 45) | Yellow / White (CGA Pin 6) |
| 7 | MONO VIDEO (CVBS) | Out | 1 Vpp 75 Ω 80-Column Monochrome Luma + Sync! | Yellow RCA Center Tip (Instant 80-Col!) |
| 8 | HSYNC (TTL) | Out | 5 V Digital TTL Horizontal Sync (15.625 kHz PAL / 15.734 kHz) | Orange / Grey (CGA Pin 8) |
| 9 | VSYNC (TTL) | Out | 5 V Digital TTL Vertical Sync (50 Hz / 60 Hz) | Brown / Purple (CGA Pin 9) |
2-Wire 80-Column Monochrome RCA Cable & RGBI HDMI Options
The Commodore 128 has two completely separate video chips and ports: the 8-pin DIN for 40-column VIC-IIe video, and this 9-pin D-Sub female socket for 640x200 80-column MOS 8563/8568 VDC video. In addition to IBM CGA-compatible Digital TTL RGBI (Pins 3–6, 8, 9), Commodore thoughtfully included a ready-to-use 80-column Monochrome Composite signal on Pin 7!
- 2-Minute 80-Column Monochrome RCA Cable: Solder DE-9 Male Pin 7 (Monochrome Video) to the center pin of an RCA plug, and DE-9 Pin 1 or Pin 2 (GND) to the outer RCA shield. Plug it into the Yellow Composite or S-Video Luma input of any monitor to test C128 80-column and CP/M modes immediately!
- Full 16-Colour 80-Column HDMI: Connect the DE-9 RGBI port directly to a Raspberry Pi Zero running RGBtoHDMI (with the 4-bit TTL RGBI buffer hat) for pixel-perfect 16-colour HDMI.