The Apple PC Compatibility cards come bundled with a three-headed video loop-back cable (part number 922-2216). The cable allows the routing of both the PC video signal and the Macintosh video signal to a single monitor.
Listed below are the pinouts for the 26-pin video connector and the 15-pin connector on the card, and the pinouts for the three-headed video loop-back cable:
Video Connector
| Pin | Signal | Description |
| 1 | MAC HSYNC | Macintosh horizontal sync. |
| 2,4,6,8 | GND | Logic ground |
| 3 | MAC BLUE | Macintosh blue signal |
| 5 | SENSE0 | Sense line 0 |
| 7 | BLUE OUT | Blue output from PCI card |
| 9 | HSYNC OUT | Horiz. sync. output from PCI card |
| 10 | MAC CSYNC | Macintosh contrast sync. |
| 11,13,15,17,21,24 | GND | Chassis ground |
| 12 | MAC GREEN | Macintosh green signal |
| 14 | SENSE1 | Sense line 1 |
| 16 | GREEN OUT | Green output from PCI card |
| 18 | CSYNC OUT | Contrast sync. out from PCI card |
| 19 | MAC VSYNC | Macintosh vertical sync. |
| 20 | MAC RED | Macintosh red signal |
| 22 | CABLE DET L | Cable detect low |
| 23 | SENSE2 | Sense line 2 |
| 25 | RED OUT | Red output from PCI card |
| 26 | VSYNC OUT | Vertical sync. out from PCI card |
Joystick Port
| Pin | Signal |
| 1,8,9 | VCC I/O |
| 2 | JOYF 0 |
| 3 | JRC 0 |
| 4,5 | GROUND |
| 6 | JRC 1 |
| 7 | JOYF 1 |
| 10 | JOYF 2 |
| 11 | JRC 2 |
| 12 | MIDI OUT |
| 13 | JRC 3 |
| 14 | JOYF 3 |
| 15 | MIDI IN |
Frame Ground (threaded screw holders used to attach cable)
Video "Y" Cable Pinouts, 26-pin End to PC Compatibility Card
| Pin | Signal |
| 1 | MAC HSYNC |
| 2 | HSYNC RETURN |
| 3 | MAC BLUE |
| 4 | MAC BLUE RETURN |
| 5 | SENSE 0 |
| 6 | BLUE OUT RETURN |
| 7 | BLUE OUT |
| 8 | HSYNC OUT RETURN |
| 9 | HSYNC OUT |
| 10 | MAC CSYNC |
| 11 | CSYNC RETURN |
| 12 | MAC GREEN |
| 13 | GREEN RETURN |
| 14 | SENSE 1 |
| 15 | GREEN OUT RETURN |
| 16 | GREEN OUT |
| 17 | CSYNC OUT RETURN |
| 18 | CSYNC OUT |
| 19 | MAC VSYNC |
| 20 | MAC RED |
| 21 | RED RETURN |
| 22 | CABLE DET |
| 23 | SENSE 2 |
| 24 | RED OUT RETURN |
| 25 | RED OUT |
| 26 | VSYNC OUT |
Video "Y" Cable Pinouts, 15-pin End to MAC Video
| Pin | Signal |
| 1 | RED RETURN |
| 2 | MAC RED |
| 3 | MAC CSYNC |
| 4 | SENSE 0 |
| 5 | MAC GREEN |
| 6 | GREEN RETURN |
| 7 | SENSE 1 |
| 9 | MAC BLUE |
| 10 | SENSE 2 |
| 11 | MAC SYNC RETURN |
| 12 | MAC VSYNC |
| 13 | MAC BLUE RETURN |
| 14 | CABLE DETECT |
| 15 | MAC HSYNC |
Video "Y" Cable Pinouts, 15-pin End to Monitor
| Pin | Signal |
| 1 | RED OUT RETURN |
| 2 | RED OUT |
| 3 | CSYNC OUT |
| 4 | SENSE 0 |
| 5 | GREEN OUT |
| 6 | GREEN OUT RETURN |
| 7 | SENSE 1 |
| 9 | BLUE OUT |
| 10 | SENSE 2 |
| 11 | CSYNC OUT RETURN |
| 12 | VSYNC OUT |
| 13 | BLUE OUT RETURN |
| 14 | HSYNC OUT RETURN |
| 15 | HSYNC OUT |