How to edit your Halo Cache-files.
by Laxpat101
To do this you should have previous knowledge in transfering files to and from your Xbox.
This might not be the easiest way of doing it, but I think it's comfortable.
Step1.
Load Halo on your Xbox, play the level you want to modify (Single or Multiplayer).
(Make sure you get a loadscreen, because this method needs the cache-file to be rewritten)
Restart the xbox and boot EvolutionX, or any dashboard that can transfer files via FTP.
Step2.
Connect to your Xbox via FTP, look in the folders (drives) X, Y and Z for cache-files.
They should be named cache00*.map . (* is 0-5)
Step3.
Refresh the folder to make sure you see the right time of (last) Modified.
(mostly important if you have been in the folder before)
Download the Cache-file that is newest, that should be the one you played.
Singleplayer maps are always 278mb
Multiplayer maps are always 47mb
UI map is always 35mb
(This was why it had to be rewritten, so you can see the date motified)
Step4.
Run a hex software of your choice, one that can go to Offsets in hex.
Preferable rename your cache00*.map to the map it is. Ex. blood_gulch.map.
Load the renamed file into the hex editor.
Step5.
Get your hands on some hex value lists.
Load the list for the level you are going to modify.
Step6.
Look for something you want to modify. For example change the AR bullets to Rockets.
In multiplayer projectiles can be changed to other projectiles, vehicles for other vehicles etc.
In singleplayer it's a little more free, you can change projectils into vehicles etc.
The best way to find out is to try.
The item you want to change, copy the value that looks like this: (233dbf8) and goto that offset. (Offset for Blood Gulch AR bullet)
Then type in the bytes from the item you want to replace it with: D4 83 98 80 (Bytes for Blood Gulch rocket)
Make sure you type it in the hex area. The large area filled with numbers and letters. (0-f)
Step7.
When you have changed as much as you want, save the map as the original cache-file was named. (ex. cache000.map)
Transfer it to your Xbox and overwrite the old cache-file.
Step8.
Start Halo on your Xbox and Load the level you just modified.
If it doesn't work/crash it might depend on:
The hex software never saved your file.
You replaced the wrong cache file.
You messed up the bytes.
You edited stuff that crashed the game.
Step9.
Hack away