Mitsubishi DiamondScan AUM-1381A Reference

The DiamondScan is one of the few VGA-type multisync monitors that has a composite video input, and that made it relatively common for use on the Amiga (although I believe that Mitsubishi no longer makes this model). The official scan rates cover the range from 15.6 kHz to 36 kHz, so the DiamondScan should work with all normal Amiga video modes. User controls are standard knobs and buttons, and there are no digital memory features, so using it with the Amiga means that you have to juggle the monitor's picture location settings along with the Amiga overscan and screen position settings. The DiamondScan works fine with the Amber board (see Boards/A2320 'Amber' Reference).

One feature of the DiamondScan is particularly applicable to the video production uses of the Amiga: the "Composite/RGB Select" (pin 22) on the DB25 input. Connect this pin through a switch to ground, and then a flip of the switch will select composite video or analog RGB display without reaching for the switches on the back of the monitor.


  Sync Frequency: 15.6 kHz to 36 kHz Horizontal
                  45 Hz to 90 Hz Vertical

      Resolution: Maximum 800 x 560 (Rated...normally considered to be an 800x600 monitor.)

Input Connectors

  BNC (Composite Video)
  DB9 (EGA/CGA/Mono TTL) (DB9-to-DB9 cable was included.)
  DB25 (Analog RGB)


  DB9: (For TTL 16-Color CGA)

  Pin 1: Ground
  Pin 2: Unused
  Pin 3: Red Video
  Pin 4: Green Video
  Pin 5: Blue Video
  Pin 6: Intensity
  Pin 7: Unused
  Pin 8: Horizontal Sync
  Pin 9: Vertical Sync

  DB9: (For TTL 64-Color EGA)

  Pin 1: Ground
  Pin 2: Secondary Red Video
  Pin 3: Primary Red Video
  Pin 4: Primary Green Video
  Pin 5: Primary Blue Video
  Pin 6: Secondary Green Video/Intensity
  Pin 7: Secondary Blue Video
  Pin 8: Horizontal Sync
  Pin 9: Vertical Sync

  DB9: (For TTL Mono)

  Pin 1: Ground
  Pin 2: Unused
  Pin 3: Unused
  Pin 4: Unused
  Pin 5: Unused
  Pin 6: High Intensity
  Pin 7: Video
  Pin 8: Horizontal Sync
  Pin 9: Vertical Sync


   Pin 1: Sync Ground
   Pin 2: Red Video
   Pin 3: Red Video Ground
   Pin 4: Green Video
   Pin 5: Green Video Ground
   Pin 6: Superimpose Control (YS)
   Pin 7: Superimpose Ground
   Pin 8: Video Input Select (AV)
   Pin 9: Composite Video Input
  Pin 10: Composite Video Ground
  Pin 11: Composite Video Out
  Pin 12: Composite Video Ground
  Pin 13: PGA Mode Control
  Pin 14: Blue Video
  Pin 15: Blue Video Ground
  Pin 16: Horizontal/Composite Sync
  Pin 17: Vertical Sync
  Pin 18: Unused
  Pin 19: Unused
  Pin 20: Unused
  Pin 21: INT (+5V ???)
  Pin 22: Composite/RGB Select (TTL level: Low for RGB, high or open for composite.)
  Pin 23: Analog/TTL Select (TTL level: Low for TTL, high or open for analog.)
  Pin 24: Remote (TTL level: Low to disable Mode Switch.)
  Pin 25: Shield Ground