The NeoGamma gamecube modes allow to change NeoGamma's behaviour when booting gamecube discs. All these settings are only relevant if there's a GC disc in the drive and it is "launched"

The modes:

MIOS:
Just boot the MIOS, boots the GC disc the same way as Gecko OS and the old Gamma do

external*:
Makes the MIOS boot the GC .dol located in the NeoGamma folder on sd card(sd:/NeoGamma/GC.dol). This is can be used for example to use WiiGator's 0.2 GC backup launcher instead of the modified version NeoGamma uses

internal*:
Launches the included GC backup launcher, which is a modification of WiiGator's 0.2 GC backup launcher. Currently this only boots GC games in regular mode(same as press A in the original) with the video mode selected in NeoGamma. For multi game discs, the selection which game to boot is moved to wii mode. Select 2nd disc with 1/Z, if no 2nd disc is selected it is auto detected, but currently the whole 2nd disc feature does NOT work!


*external and internal GC mode require a compatible cMIOS. WiiGator's cMIOS are compatible and Waninkoko's cMIOS rev 6+ will most likely also be compatible.