Big plan...........................little knowledge

A hopefully quick and painless question:
Being new.........(look out) I am confused regarding "firmware". It is my understanding that the firmware contains basic instructions that the machine will recognize and execute on power up? These include seeking out the end stops (limit switches) and moving all axes to those switches and thus homing itself to the XYZ "00" position, at which point the machine knows where it is and can respond to any G-code file loaded? If this is correct, my question is this:
Does each processor have these firmware instructions preloaded or does the user have to program those instructions? If they have to be programmed, do all different brands of processors utilize the same programming language?
Just an FYI: I do have limited cnc experience and have a reasonable understanding of the concepts involved
As you all can see, I clearly have a steep learning curve ahead, riddled with literally thousands of questions. But for now, if someone can answer this then I can call it a good start.
Thank You in advance
oldtimer

Hey Oldtimer, Very good question, it shows you're thinking about this seriously before you jump in (but just jump in anyway... the water is great!)

The simple answer is yes the firmware controls the way the hardware reacts to commands from the GCode of the print you are running. The good news is that you will need to learn a little about setting certain things in the code to get the best prints, but the printer will either already have working firmware on it ready to go if it's a prebuilt printer. Or, if you get a kit to build yourself it will either come with the firmware and software or provide links to download the files that are purpose made for that kit.

So in reality you can pretty much just start printing with what is supplied with the printer or kit, and then start to add little tweeks here and there to tailor the performance for your needs as you go. It's not that hard and is just part of the process of learning about 3D printing just like how to calibrate extrusion rates and how to prepare the bed so the print sticks properly. There are lots of good videos on youtube and elsewhere to guide you through, so even if it's not entirely clear right now, it will be after you watch a few videos and ask a few questions.

Thank You Drone!
One of the reasons I was asking is because I'm not utilizing a pre built or a kit either. As always, things happen and this time it was an auction where I had gone to look at a specific item and when it was time to leave, my friend had found a small desk top machine and the more we looked at it the more it seemed as it would be a perfect candidate to repurpose as a 3d printer. So $40 later the hook was set and now we 're trying to figure out what to do next.
I now, I know..............what were you thinking!! ( the "machine" in question was basically a small CNC machine used to despense liquids, but is constructed with all the attributes of a 3 axis CNC, complete with steppers and computer) The big draw was it has a bigger envelope than most of the available machines............ we'll see!!
I have been considering the "Smoothieboard" processor. I liked it because it appears to have very good documentation (I need that!!)as well as more than adequate features for the "project". Does anyone have experi
Either way..................I'll have a lot of fun for the $40 invested and most importantly I will learn!!
Thanks again for the response

Go with RAMPS It is cheaper, more widely used and more versatile once Marlin is in there.

OK, Thanks for responding. reading about ramps..................