In order to be able to use commands like M500, M501 and M503 in Marlin you have to modify configuration.h file and enable EEPROM settings.
Open Configuration.h file
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If you move your 3D printer or CNC machine manually using G commands and at some point device stops moving, it might be due to hitting software endstops.
Marlin has the ideas of software endstops. This is an additional security measure…