This is a simple breakout PCB for the Ten64 which converts the 26-pin, 1.27mm/0.050" pitch GPIO/Control Header to the more standard 2.54mm/0.100" pitch pins.

See https://ten64doc.traverse.com.au/hardware/control-header/ for the board side of the control header.

This is more convenient than using a ribbon cable for accessing small numbers of GPIOs but is not recommended for production as the connection to the host board is not keyed / constricted.

GPIOs are broken out into two rows of 13 pins for each side of the board header.

Warning: The interface with the host board is not "keyed" and shrouded (unlike an IDC ribbon cable) so it is very easy to misalign the connector.

A good way to be sure is to check that the first and last pins on both rows are connected to GND.

The interface with the board connector is effectively "friction-fit" so no guarantees are made about it's ability to withstand vibration and movement during transit.

This board is not a Traverse Product and is not supported for production use for reasons stated above

You should also be mindful of the limitations of the GPIOs started in the Ten64 manual - many of these pins come from the LS1088 SoC and may not be forgiving against ESD, shorts and overvoltage as a microcontroller.