G Codes and various firmwares

[Eaglezsoar]

The wiki at http://reprap.org/wiki/G-code lists all the various g-codes and which firmware supports the various codes but if a code is not supported, it does not give an alternative.
Throughout these various forums I see things like G-?? to turn on this or a M-?? to do that and I am confused. Is there anywhere it is documented that if you are using Marlin these are
the appropriate codes to do various functions or if you are using Repetier these are the appropriate codes. For example, the wiki lists the following:
M106: Fan On
Support FiveD Teacup Sprinter Marlin Repetier
yes yes yes

Example: M106 S127

Turn on the cooling fan at half speed.

Mandatory parameter 'S' declares the PWM value (0-255). M106 S0 turns the fan off. Supported by TeaCup, Sprinter, and Marlin Repetier is NOT mentioned

What is the same code for Repetier? I hope that all can understand what I am trying to say. One other question, what is the best way to print out the entire wiki and not lose the way it is formatted?

[Highcooley]

You find a list of all valid GCODES in most firmwares:
e.g.
https://github.com/repetier/Repetier-Fi ... petier.pde
https://github.com/ErikZalm/Marlin/blob ... n_main.cpp

[Eaglezsoar]

You find a list of all valid GCODES in most firmwares:
e.g.
https://github.com/repetier/Repetier-Fi ... petier.pde
https://github.com/ErikZalm/Marlin/blob ... n_main.cpp

Thanks! It seems everything is there, it's just so scattered it's not easy to find.

[Highcooley]

I know...this hobby takes ages to discover all the relevant information and knowledge. However, most attempts to gather this information in one single place failed after a short time, as the information is constantly changing and projects mushroom. Standardised tools to publish the relevant intelligence about projects, printers, software and procedures would be a blessing. Maybe Web 2.5 or 3.0 is one day coming