Macintosh SE and SE/30 Analog board to logic board connector (J12) pinout. Order is left to right top to bottom with Pin #, wire color, then description:

  1. Black GND
  2. Black GND
    (twisted pair with VIDEO)
  3. Black GND
    (twisted pair with HSYNC)
  4. Black GND
  5. Black GND
  6. Blue -5V DC
    (For serial)
  7. Green -12V DC
    (For serial)
  8. Black GND
  9. White VIDEO
    (starts 11.2μs after falling edge of HSYNC, lasts about 33μs, first data line is 1.26ms after falling edge of VSYNC)
    (Paired with ground connector #2)
  10. Purple HSYNC
    (square wave, falling edge triggered, 45μs per line)
    (Paired with ground connector #3)
  11. Gray VSYNC
    (square wave, falling edge triggered, 60.10 Hz / 16.64ms per frame, 180μs low)
  12. Orange +5V DC
  13. Orange +5V DC
  14. Yellow +12V DC