Halo: Combat Evolved
From xboxdevwiki
Debugging
To enable debugging of the original NTSC version with xbdm (be sure to use the retail xbdm version 5455 if on a retail box due to low memory constraints) replace the single instance of 6A 00 FF 74 24 08 E8 35 with 33 C0 40 C2 04 00 E8 35 in the default.xbe which will skip a call to XnTerm.