A USB adapter for a vintage Depraz mouse #VintageComputing

Produced in the early 1980s, The stylish Depraz mouse was used in several systems, the most interesting being the Blit and its descendants, the DMD 5620 and others.

John Floren acquired one from Ron Minnich. The mouse was ex-Bell Labs, previously in the ownership of the late Jim McKie. John had always wanted to try using one…

The mouse has a male DE-9 connector. This might make you assume it speaks the same serial mouse protocol we all knew and loved back in the 90s, but you’d be wrong–and the first hint should have been that it’s a male connector, when all those serial mice had female connectors.

I had to post on the TUHS mailing list for help, but I was quickly pointed at this page, which informed me that the mouse is one of those old-fashioned types which directly expose the outputs of their quadrature encoders over the connector. The pinout is:

  • Pin 1: +5V
  • Pin 2: Y1 encoder
  • Pin 3: Y2 encoder
  • Pin 4: X1 encoder
  • Pin 5: X2 encoder
  • Pin 6: GND
  • Pin 7: Middle mouse button
  • Pin 8: Right mouse button
  • Pin 9: Left mouse button

Using a DE-9 breakout adapter, I wired the mouse to an Arduino Pro Micro.

The code is at github.com/floren/depraz-arduino. John believes it should be suitable for use with any quadrature mouse, provided it is wired up properly.

See the video below and full details in the article here. There is bonus info on how the mouse was weighted also.


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