Using the parallel port on the MESA 7i95?

I'm replacing a 15-year-old PC on a Birmingham CNC mill with a NUC interfaced to a MESA 7i95. I picked the 7i95 because it's specs say it can be used to interface to non-MESA equipment via its parallel port interface. I want to use the 26-pin interface on the 7i95 to connect to the old BoB initially. I may eventually replace the BoB with the 7i95, but not yet.

Since LinuxCNC 2.8.1 does not have a PNCConf that knows about the 7i95, I started from a set of files that a user modified from a 7i76 set.

I'm lost. I cannot figure out how to connect the parallel port physical I/O pins to the hostmot2 stepgens. I think I'm missing something fundamental. The hostmot2 doc say that the pins are assigned(?) "at board-driver load time", but does not say how to do this. Any guidance?

If this is a first time LinuxCNC setup I would not use the BOB and
use the 7I95s step/dir and I/O pins. This will be much easier to configure.

Not really a first-time situation. the BoB is fully wired up to four Geckos, a VFD, limit switches, and coolant relays, and I would prefer to avoid moving all those 15-year-old wires. I also messed around with Machinekit on a BBB and got the system working, but the boot time was too slow, graphics support is unacceptable for Axis, and the system fails after an hour or less probably due to something strange in the USB setup (long story) so I was looking for a quick and simple fix. I could kludge a cable from the discrete screw terminals on the 7i95 to a DB-25 parallel port connector, but the whole reason for selecting the 7i95 in the first place was that I thought it already had a fully-configurable 2x13 parallel port interface.

The 7I95 can drive any parallel port BOB but would need firmware for that that
specific BOB, plus the 7I95 is really intended to run stand alone (if you wanted to
drive a parallel port BOB, a 7I92/H/M would have been a better choice as it already
has firmware for most standard parallel port BOBs)

Oh, well. I guess I will wire a DB-25 cable to the appropriate 7i95 pins, at least until I can learn how to write firmware for that FPGA. Does MESA have documentation for writing the firmware somewhere? VHDL or Verilog?

I'm assuming that there must exist firmware source code for the 7i95 and that it is available to be modified. My Xylinx FPGA skills are very rusty, but I would hope that reassigning the pins would be a fairly straightforward change. I will have some wiggle room because I can remove several modules. I assume my tasks would be to download and install the Xylinx dev system (is it still ISE?), download the MESA 7i95 project, and then study. Comments?

Yes you would download the 7i95.zip file from mesa and ISE14.7 from Xilinx

If you connect the 7I95 step/dir pins directly, why would a DB25 be involved at all?
That is, why would you need to keep the parallel port breakout?

The machine is a big knee mill, like a Bridgeport. It was converted to CNC berore 2005, and all the wires run to a Sound Logic Bob In an enclosure bolted to the side of the machine's base. I do not want to mess with all that old wiring yet, so I want to just plug a parallel port cable into the old BoB. Otherwise, I will need to fabricate a new enclosure or run a lot of wires. This old BoB also has some 120 VAC relays and an opto-isolated interface to the old VFD spindle control. To use the 7i95, with no firmware change to drive a parallel port cable to plug into the BoB, I would (apparently) need to connect the individual wires in the parallel port cable to the screw terminals on the 7i95.

Where exactly on the MESA site (or elsewhere) can I find 7i95.zip?

www.mesanet.com/software/parallel/7i95.zip

It should be in the same place as the manual in the store also