Case for Arduino Nano to parallel port

I started building a CNC machine in 2010 using the design in the book "Build Your Own CNC Machine." I hit a road-block when I realized that my computers no longer have parallel ports and the USB to parallel adapters don't work with the break-out board I have. Then I got distracted by 3D printing and set the CNC aside until a few months ago when I found out about using the Arduino and GRBL (https://github.com/gnea/grbl/wiki). My breakout board is not well documented but I managed to figure out