Dump the parallel port along with the BOB and invest in an AXBB-E, you won't regret it, it will transform the machine and user experience.

You can use either Mach3 or UCCNC with the AXBB-E but I strongly recommend you go with UCCNC as it's fully supported by the people who actually manufacture the controller.
Because of this, it's much more in tune with the hardware and updated when any major changes occur. In real-world use, the motion is much smoother than mach3 and in reliability terms, it's rock-solid stable which mach3 certainly isn't and never will be. It's also much cheaper than Mach3.!

If you do decide to go with AXBB-E or UCCNC then get in touch as I keep these in stock for machines I build and I'm happy to supply them to forum members.