Pinning together a VGA cable
I sat down with a multimeter and traced the pins on the iMac video circuit back to the motherboard, so I can make a (short) iMacga to VGA converter cable. fortunately for me it's just a simple remapping of pins and I don't have to wire together another circuit to remap levels.
| 1 RED ground | 9 RED |
| 2 BLUE ground | 10 BLUE |
| 3 GREEN ground | 11 GREEN |
| 4 N/C | 12 Hsync |
| 5 Sync ground | 13 Vsync |
| 6 sense 1 | 14 Sync ground |
| 7 sense 2 | 15 Comp. Sync |
| 8 Sync ground | 16 N/C |
| iMac | VGA | |
|---|---|---|
| 1 | ↔ | 6 |
| 2 | ↔ | 8 |
| 3 | ↔ | 7 |
| 5 | ↔ | 10 |
| 6 | ↔ | 11 |
| 7 | ↔ | 12 |
| 8 | ↔ | 10 |
| 9 | ↔ | 1 |
| 10 | ↔ | 3 |
| 11 | ↔ | 2 |
| 12 | ↔ | 13 |
| 13 | ↔ | 14 |
| 14 | ↔ | 10 |
VGA pins 4-7 are all tied to ground (some diagrams tie them to pin 8 [Sync ground]); pins 9 & 15 are not connected; ping 12 is claimed to not be connected, but if my translation is correct here the Mac links that one to the (grounded) sense 2 pin.
I'm taking bets over whether the g3 will physically explode out of the socket when I wire up this cable and attach it to a monitor.