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Undocumented G/M Codes  

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hyiger
(@hyiger)
Famed Member
Undocumented G/M Codes

Was curious to know if there was any g/m-code that is undocumented. So I had the AI summarize if for me

From Prusa Knowledge Base: Buddy firmware-specific G-code commands

In the firmware (sorry the HTML tables are not getting formatted correctly)

Codes unique to Core One

Code Feature flag Notes
M870 HAS_CHAMBER_VENTS Automatic chamber vents — open (O) or close (C) the intake grille. The static_assert(HAS_CHAMBER_VENTS()) in the header means it will not compile for any other printer.
M961 HAS_MANUAL_BELT_TUNING Manual belt tuning wizard. (Automatic belt tuning M960 is iX-only, not Core One.)
M1980 HAS_DOOR_SENSOR_CALIBRATION Door sensor calibration wizard. MK4 has the door sensor hardware (HAS_DOOR_SENSOR) but only Core One has the calibration routine. Note: the source docstring incorrectly labels this M1979.

Codes shared with iX and/or XL (not other printers)

Code Feature flag Also on
M1977 HAS_PHASE_STEPPING + calibration XL, iX — phase stepping calibration dialog
M9200 Input shaper reload from config store XL, iX (all printers with input shaper)
M9202 HAS_PRECISE_HOMING_COREXY iX, XL, XL Dev Kit — clears CoreXY 9-point homing calibration, forcing a full recalibration on next G28

Codes that apply to all (or other) printers

Code Applies to Notes
G123 All GUI manual move — moves axes at MANUAL_FEEDRATE, stops when a new G-code is queued
P0 XL only Park/drop current tool (toolchanger)
M104.1 XL only Early set hotend temperature — preheat a tool in advance using time-until-needed parameter
M147 / M148 Printers with chamber filtration Override chamber filtration on/off for current print only (ignores filament settings)
M262M268 MK3.5 / MK3.9 / MK4 IO expander pin read/write/configure (XBUDDY board TCA6408A chip)
M865 All Manage filament parameters — set/query name, temperatures, abrasive flag, chamber settings
M876 MINI only Handle host prompt response / trigger warning popup by WarningType index
M960 iX only Automatic belt tuning — frequency sweep to measure resonance and tensioning force
M1200 All (Prusa Connect) Signal to Prusa Connect that the printer is ready for a new print job
M1703 All with WiFi Run Wi-Fi setup wizard (A = initial setup, I = load INI file, bare = normal wizard)
M1959 All with ISC Input Shaper Calibration wizard — sweep 30–80 Hz on X and Y axes, compute best shaper, optionally apply
M1978 All Fan selftest dialog — tests print fans, heatbreak fans, enclosure/chamber fans at 100% and 40% PWM
M9140 / M9141 / M9150 All Disable / query status / enable stealth mode (affects time estimation and motion limits)
M9201 All Reset motion parameters to defaults (Motion_Parameters::reset())
M9933 All Internal Cork tracker — C marks a print-job milestone as done
Posted : 26/02/2026 12:23 am
3 people liked
Robin_13
(@robin_13)
Honorable Member
RE: Undocumented G/M Codes

Useful information.

 

Posted : 14/03/2026 5:05 am
Sembazuru
(@sembazuru)
Noble Member
RE:

What printer is model "iX"? It's probably something obvious, but I'm not grokking it at the moment.

See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs

Posted : 17/03/2026 8:15 pm
gb160
(@gb160)
Prominent Member
RE:

I assumed it's Prusa i1,i2 & i3

Posted : 17/03/2026 9:04 pm
1 people liked
PaKo
 PaKo
(@pako)
Eminent Member
RE: Undocumented G/M Codes

I think, that iX seems to be INDX (M960 - automatic belt tunning)

Posted : 18/03/2026 5:04 pm
gb160
(@gb160)
Prominent Member
RE: Undocumented G/M Codes

No that page was last updated 11 months ago.

Posted : 18/03/2026 5:08 pm
PaKo
 PaKo
(@pako)
Eminent Member
RE: Undocumented G/M Codes

On presented page are described Prusa specific g-codes. @hyiger writes about "undocumented" g-codes. In presented table is row "indexM960 iX only Automatic belt tuning — frequency sweep to measure resonance and tensioning force" And automatic belt tunning is one of the new fuctions of INDX extruder.

Posted : 18/03/2026 5:49 pm
gb160
(@gb160)
Prominent Member
RE: Undocumented G/M Codes

Its not INDX, why would they be documenting INDX gcode on a page last updated 11 months ago?

 

eg:
G54_59 - Select a new workspace 

(For iX printers only)A workspace is an XYZ offset to the machine native space. All workspaces default to 0,0,0 at start, or with EEPROM support they may be restored from a previous session.G92 is used to set the current workspace's offset.

Maybe it's referring to those industrial machines they make.

 

Posted : 18/03/2026 6:08 pm
hyiger
(@hyiger)
Famed Member
Topic starter answered:
RE: Undocumented G/M Codes

 

Posted by: @gb160

Its not INDX, why would they be documenting INDX gcode on a page last updated 11 months ago?

 Maybe it's referring to those industrial machines they make.

It's most likely the print farm setups due to one of the instructions being "Automatic belt tuning"

Posted : 18/03/2026 6:11 pm
1 people liked
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