New wifi card causes second parallel port to stop working

Never said it wouldn't

Only mentioned on board serial & parallel ports on the ISA bus. Which is still there only not physically.

lspci -v should list multiple addesses, try all of them.

Sometimes only one address works.

This tool may be useful:
www2.langdonstaab.ca/files/parportmgr_install.txt
yyao.ca/projects/ParallelPortLinux/

(I made an install script, I think it works)
I don't know the guy who actually wrote this, I just found the program on google. It does work for me.

I do have ethernet, and I do have a reason for needing wifi in addition. The camera I'm adding to the spindle sends video via wifi.

Below is dmesg output with the wifi card installed. Without it, I think everything is the same except the second card is addressed 0xdcc0 instead of 0xacc0. I can try that later if needed.

Tommylight, I do have the means to change the MB parallel port address. Sounds like something to experiment with, thanks. I have swapped slots for the wifi card and the second parallel port card, same result.

I did verify that the wifi card is known to work with Linux. I don't see why LinuxCNC would care (or know anything) about the wifi card. Any issue here?

$ dmesg | grep parport
[ 7.560447] parport_pc 00:03: reported by Plug and Play ACPI
[ 7.560518] parport0: PC-style at 0x378 (0x778), irq 7 [PCSPP,TRISTATE,EPP]
[ 7.665553] lp0: using parport0 (interrupt-driven).
[ 8.274698] parport1: PC-style at 0xbcc0 (0xbcc8), irq 30 [PCSPP,TRISTATE,EPP]
[ 8.381897] lp1: using parport1 (interrupt-driven).
[ 8.390482] parport2: PC-style at 0xacc0 (0xacc8), irq 16 [PCSPP,TRISTATE,EPP]
[ 8.493589] lp2: using parport2 (interrupt-driven).

Whoa!

I think streaming video to your PC during machine operation is gonna really increase latency, especially as you probably don't have a dedicated graphics card.

Why not just connect the PC to a wireless router via ethernet and then connect the camera the same router wirelessly?

The PC and camera can communicate via the router without any Wi-Fi card in the PC.

Problem solved!