What do I need to switch to LinuxCNC

If you go to Mesa's 7i76e product page, you can download a zip file containing a series of prebuilt firmwares. It looks like there are a couple of ones that allow 1 x 7i76 an 1 x BOB on those two 25 pin headers.

PCW might advise which one you should use.

Installing the firmware is done with Mesaflash which should be distributed with the Linuxcnc ISO.

How do I change the firmware? Is it just settings, or is it software?
Perhaps I should convert my Plasma table first It's much less used than the mill as this may take a while?

What may need changing is the set of functions available on the 7I76E's expansion
connectors. That is, there is a 7I92 configuration for a PMDX126, since that's a common
breakout board but its a bit odd to use one with a 7I76E. FPGA firmware is compiled
with a specific set of features on specific pins (Step generators. PWM generators, UARTS,
encoder inputs etc etc)

A 7I76E+PMDX126 config will be a bit odd also because of the mapping of things
like step generators. That is, the most natural mapping if you start with a PMDX126
would to put the first 4 stepgens on the PMDX and then the next 5 on the 7I76E
In fact

The FPGA firmware is supplied as .bit files that are written to the 7I76E card with the
mesaflash utility.

Here is some example firmware for a 7I76E + PMDX126 the puts the first stepgens on the
expansion port setup for a PMDX126:

I downloaded toe Manual from the Mesa site. It seems to be a nice detailed technical reverence, that I'm sure is great for you experienced Linux CNC users, but I don't see any installation guide/getting started guide. Am I missing something? Also I went on YouTube and there are no videos in English on the 7i76e. I can't find Mesa Flash on my machine. Is this a brand new offering from Mesa?

Do you know if the Mesa Ethernet port can be on the LAN or should it be an isolated separate network? On my ESS they recommend a separate isolated network.

mesaflash (case is important) should be available (its part of current
LinuxCNC distribution) If not it can be added.

And yes, the 7I76E should be on its own network. Normally it should use the hosts
on board network interface, and internet/file sharing should be done with WIFI or a USB
Ethernet dongle etc

New plan. I'm going to skip the PMDX breakout board half step idea and instead either wire directly to my CNC plasma table (which can be down for an extended period) or perhaps a test bench setup on my office with loose motors while I'm getting my Linux legs. Do I still need to load special firmware?

Is there an install guide? The manual I downloaded is a technical reference manual.

The installed firmware is fine for a stand alone 7I76E

What specific information do you need for installation?

There are some very good wiring diagrams on the forum, the search function will find them.
Have a browse through the forum, you’ll be amazed the info you pick up.
mesaflash is there,will return the full path to the binary, if it doesn’t it’s not there.
Or type mesa press TAB and that will display any programs in your path that start with mesa, fairly sure the NT versions of cmd.exe had that behaviour.
You may want to do a basic refresher on using the command line, it’ll save you a lot of time rather than if you try to rely on the GUI as in Windows.
Try mc it’s like the old Norton file manager, you may feel in familiar territory. And don’t panic.

ok so I do have mesaflash, good, thanks for the tips there!

Sounds like there is no Mesa Quick start, install or setup guide. Is there a setup program to set the IP address or anything I need to know to setup this card when it arrives?

Normally you would setup the network connection with either the network manager GUI
or by editing the interfaces file. Some details of GUI setup will be Linux version dependent.

tommylight has instructions for setting up the IP address via the GUI:

forum.linuxcnc.org/27-driver-boards/3559...ethernet-mesa-boards

The low level method (editing the interfaces file) is described in the hm2_eth manual page