Got a CNC machine that uses a parallel port interface? What’s the best way to control it? In the field of CNC machines, GRBL is the means of transmitting G-code via a serial communications connection. So, basically, what you can do is run a serial communications connection to an Arduino, then break out a parallel port from there to connector your CNC machine.
20200727/https://hackaday.com/2014/09/16/usb-to-db25-adapter-uses-grbl-for-parallel-port-cnc-communication/