The following is a list of selected Gcodes supported by Marlin firmware and fully tested and supported by the Series 1
G1 - Coordinated Movement X Y Z E F; for example "G1 X130 Y115 Z115 E30 F10000"
XYZ are the motion axes, E is for Extruder and F is feedrate.
G4 - Dwell S (seconds) or P(milliseconds); for example "G4 S2" or equally "G4 P2000"
G10 - retract filament according to settings of M207
G11 - retract recover filament according to settings of M208
G28 - Home all Axes or ones specified; for example "G28" will home all axes but "G28 X" would only home X.
It is recommended but not required to do this every time you turn on your Series 1
G90 - Use Absolute Coordinates
G91 - Use Relative Coordinates
G92 - Set current position to coordinates given; for example "G92 E0" is common because it states that the Extruder position is at zero. In a sense it's a way to home the extruder.
M104 - Set extruder target temp; for example "M104 S185"
M105 - Read current temp
M106 - Fan on, control PWM; for example "M106 S255" which is the same as "M106" or "M106 S128" for fan at half-power.
M107 - Fan off. ("M106 S0" would do this too.)
M109 - Set extruder target temp AND wait for extruder to reach target temp before continuing; for example "M109 S185"
M114 - Display current position.
M17 - Enable/Power all stepper motors
M18 - Disable all stepper motors; same as M84
M82 - Set E codes absolute (default)
M83 - Set E codes relative while in Absolute Coordinates (G90) mode
M84 - Disable steppers until next move, or use S to specify an inactivity timeout, after which the steppers will be disabled. S0 to disable the timeout.
M85 - Set inactivity shutdown timer with parameter S. To disable set zero (default)
M92 - Set axis_steps_per_unit same syntax as G92
M140 - Set bed target temp, just like M104 for the hot end. (you have to have a heated bed on your machine, of course)
M190 - Wait for bed current temp to reach target temp. See M109 for clarification of same thing for hot end. (you have to have a heated bed on your machine, of course)
Nitty Gritty Custom M-Codes (Advanced Use Only):
M200 - Set precice filament diameter
M201 - Set max acceleration in units/s^2 for print moves (M201 X1000 Y1000)
M203 - Set maximum feedrate that your machine can sustain (M203 X200 Y200 Z300 E10000) in mm/sec\
M204 - Set default acceleration: S normal moves T filament only moves (M204 S3000 T7000) im mm/sec^2 also sets minimum segment time in ms (B20000) to prevent buffer underruns and M20 minimum feedrate
M205 - advanced settings: minimum travel speed S=while printing T=travel only, B=minimum segment time X= maximum xy jerk, Z=maximum Z jerk, E=maximum E jerk
M206 - set additional homing offset
M207 - set retract length S[positive mm] F[feedrate mm/sec] Z[additional zlift/hop]
M208 - set recover=unretract length S[positive mm surplus to the M207 S*] F[feedrate mm/sec]
M209 - S<1=true/0=false> enable automatic retract detect if the slicer did not support G10/11: every normal extrude-only move will be classified as retract depending on the direction.
M220 - S- set speed factor override percentage
M221 - S- set extrude factor override percentage
M301 - Set PID parameters P I and D
M302 - Allow cold extrudes
M303 -PID relay autotune S sets the target temperature. (default target temperature = 150C)