The standard 4-pin S-Video connector used on most video and television equipment is functionally identical and fully compatible with the 7-pin S-Video input connector used on the Quadra 660AV, 840AV and Power Macintosh 6100, 7100, 8100 AV card.
The only difference between the two connectors is that Apple provides three additional inputs, I^2C clock, +12V, I^2C data, that were intended for future products and expansion.
A standard 4-pin S-Video cable available at most electronics stores will fit into the Apple 7-pin S-Video input connector without a problem. No adapter cable is necessary because pins 5, 6, and 7 are unused.
Below is a chart showing the pinouts of both the 4-pin and 7-pin connectors:
The only difference between the two connectors is that Apple provides three additional inputs, I^2C clock, +12V, I^2C data, that were intended for future products and expansion.
A standard 4-pin S-Video cable available at most electronics stores will fit into the Apple 7-pin S-Video input connector without a problem. No adapter cable is necessary because pins 5, 6, and 7 are unused.
Below is a chart showing the pinouts of both the 4-pin and 7-pin connectors:
| Pin # | Description | Pin # | Description |
| 1 | AGND (signal) | 1 | AGND (signal) |
| 2 | AGND (power) | 2 | AGND (power) |
| 3 | Video Y | 3 | Video Y |
| 4 | Video C | 4 | Video C |
| 5 | I^2C clock | ||
| 6 | +12 V | ||
| 7 | I^2C data |