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
10 / 100Base-TX Pairs
Uses ONLY 2 Pairs: Pins 1–2 (TX+/TX- Orange Pair) and Pins 3 & 6 (RX+/RX- Green Pair)
1000Base-T (Gigabit)
Uses all 4 Pairs bidirectionally (Pins 1–2, 3–6, 4–5 Blue Pair, 7–8 Brown Pair)
Full Pin Assignment & Wiring Reference
| Pin | Signal Name | Direction | Electrical Spec / Role | Wire Colour / SCART / Adapter Target |
|---|---|---|---|---|
| 1 | TX+ (BI_DA+) | Out | Transmit Data+ (10/100Base-TX) / Bidirectional Pair A+ | T568B: Orange/White (T568A: Green/White) |
| 2 | TX- (BI_DA-) | Out | Transmit Data- (10/100Base-TX) / Bidirectional Pair A- | T568B: Orange (T568A: Green) |
| 3 | RX+ (BI_DB+) | In | Receive Data+ (10/100Base-TX) / Bidirectional Pair B+ | T568B: Green/White (T568A: Orange/White) |
| 4 | BI_DC+ (PoE+) | I/O | Gigabit Pair C+ / Mode B PoE Positive (Unused in 10/100) | Blue |
| 5 | BI_DC- (PoE+) | I/O | Gigabit Pair C- / Mode B PoE Positive (Unused in 10/100) | Blue/White |
| 6 | RX- (BI_DB-) | In | Receive Data- (Paired with Pin 3!) / Bidirectional B- | T568B: Green (T568A: Orange) |
| 7 | BI_DD+ (PoE-) | I/O | Gigabit Pair D+ / Mode B PoE Negative (Unused in 10/100) | Brown/White |
| 8 | BI_DD- (PoE-) | I/O | Gigabit Pair D- / Mode B PoE Negative (Unused in 10/100) | Brown |
Troubleshooting Retro 10Base-T Ethernet Adapters (CS8900A / W5100 / ENC28J60)
Holding the transparent 8P8C (RJ45) plug with the gold contact fingers facing you and the cable entering from the bottom, Pin 1 is on the far left and Pin 8 is on the far right.
- Older 10Base-T retro Ethernet cards (such as the C64 RR-Net, Amiga A2065 / PCMCIA 3Com cards, and Apple II Uthernet) do not support Auto-MDIX: if plugging directly into another retro machine without a switch, use a T568A-to-T568B crossover cable (swapping Pins 1–2 with Pins 3–6).