jblain wrote:I eventually want to drive stepper motors trough the 7I76, but for the moment, I would just connect my current setup directly to the db25 cable coming out of the 5i25
If the firmware on the board is for the 7i76 then you would need to change the firmware to use it like a parallel port. (the "wasted" GND pins have a function in the 7i76 configuration, and none of the pins actually carry conventional bit-level signals).
You can change the firmware, there is a utility in the "support software" pack for the 5i25 that you can download from Mesa. Note that the file is Zipped, so the Linux utility loses it's executable tag, and you will need to chmod 775 it to get it to work.
This thread describes how to make pncconf work with the 7i76.
www.linuxcnc.org/index.php/english/compo...=14940&limit=6#14940