Mitsubishi MR-J3-XX"A" drive + 7i94 config?

X2 goes to the FPGA, for whatever expansion i may need. 4 diff pairs + ~40 single ended lines. for now i have a mezzanine board for old MR-S servos and another for interfacing meldas 6 base board...
yes, a combo... SV2 has 9 bidirectional RS-422/485 pairs. can be directly plugged MR-J/J2/J2S-B or MDS-A/B/C1/R-V/SP drives. or generate step/dir pulses. or read abz/serial encoders. whatever...

That sounds pretty awesome. Does it interface similar to how the MESA cards do, with a HAL file and firmware that is written to the card?

Would you share the hardware info for the X1 connector, so I can design a card that could plug in? (I can probably buy a main card from you as soon as you're ready to sell it, and I may be able to be helpful with the firmware but I've not done FPGA programming in over 20 years)

X1 just has 5V power and rs-485 YIO bus...