Joined up to say a big thank you to BigJohnT
I'm almost done with my baptism by fire with getting LinuxCNC working and followed his instructions to install Linux Mint 19.1 RT Kernel & Linux Mint 19 LinuxCNC and it's alive !
I'll try do a build log when I get a chance to document my trials and tribulations to hopefully make others lives easier. This is my first time with LinuxCNC and haven't touched Linux in about 20 years so was a steep learning curve.
The short of it is Dell 9020 SFF with SYBA SD-PEX10005 & Gecko G540
Originally tried the version as per the download link found at
linuxcnc.org/docs/2.7/html/getting-start...etting-linuxcnc.html
Lan doesn't work, tried for a while but no success
Tried stretch version from here
www.linuxcnc.org/testing-stretch-rtpreempt/
Lan worked, everything seemed to work, used lspci - v and confirmed Parallel card working (address was e010 for mine), When booting LinuxCNC would get an error about Linux parallel port not found & Unexpected realtime delay on task 0. Unable to get any motion. After exiting LinuxCNC reran lspci - v and noticed that the Parallel card was now coming up as disabled, reboot would re-enable it but as soon as I loaded LinuxCNC again it would disable it.
Installed Mint 19.1 as per BigJohnT's instructions, ended up with the same problem, on a whim changed the Parallel card from the short PCIE slot (16x but wired as 4x) to the full size PCIE 16x slot. Problem solved. No idea why this changed anything and hadn't seen this mentioned anywhere but it fixed the issue so I'm happy, was only leaving the full size PCIE empty just in case.
I think it would probably have worked on the Stretch, but Mint 19.1 is much nicer and I'm getting comparable latency so why not.
A couple of observations / questions
The install for me with a reasonable internet connection took maybe 5 hours, this is vs maybe 1/2hr on the stretch install so not something I would want to be doing on a dozen machines one after the other.
My Mint 19.1 install appears to be about 35gb, this isn't a problem as I gave it a 60gb partition to run with (dual boot with windows) but I could have easily been caught out if I hadn't of allowed it enough space.
Booting takes about 5 minutes with most of the time just a blank screen, this was rather off putting as at first my thought was that it had crashed. Not sure if the roughly 35gb install and 5min boot time is normal ?
Once it's booted it seems snappy and stable, just really slow booting.
Once again thank you BigJohnT for your step by step, was as easy as copy and paste.