Well, you are certainly not stuck as [Bray] has come up with a USB to Parallel Port Adapter solution specifically for CNC use. A cheap off-the-shelf USB to DB25 adapter may look like a good idea ...

The DB25 connector is mainly used for serial connections, allowing for asynchronous data transmission as provided by standard RS-232 (RS-232C). It is also used for parallel port connections and was ...

My X31 had a parallel port, and there was a serial port on the optional UltraBase. I've never seen the UltraBase in person, but I expect it makes the X31 one thick but tiny footprint beast. I ...