Hack 54. Hack Halo 2 by Hand

Hack Halo 2 with a hex editor.

Although there are some great programs to help you hack Halo 2, you'll occasionally need to get down to the lowest level possible. Welcome to the true old-school method: hexadecimal editing.

This hack shows you one of the most popular (at the time of writing) uses of hexadecimal Halo 2 hacking. That is, adding a new map to the multiplayer maps menu.

Remember that if you mess something up, you can get the original files from your official Halo 2 DVD. First, open the map in a hex editor. In this example, I am using Hex Workshop.

At offset 0x000001BC, you will see the name of the original map in plain text. Change this text to your map name. You must remember that you cannot alter the size of the file. In other words, you have to put in exactly the same number of characters as you remove. If your path is shorter than the original path, then you must replace the missing characters with zeros. You cannot use a string that is longer than the original. In this example, you are changingscenarios\multi\lockout\lockout to scenarios\multi\test\test000000 (see Figures 6-19 and 6-20).

When you type in your new name, you will be typing over the original characters. There is no need to use the Delete key.

Figure 6-19. The original hex before the change

Figure 6-20. The ASCII after the change

Next, open mainmenu.map in one of the Halo 2 modding apps ADI [Hack #50], Ch2r [Hack #51], or DotHalo [Hack #52]. In this example, you'll open up the menu in Ch2r. Go to the [matg] globals tag in the tag browser window (see Figure 6-21).

Figure 6-21. The mainmenu.map file open in Ch2r

Next, you'll need to open the globals.matg tag so that you can edit the metadata (see Figure 6-22).

Figure 6-22. Editing the metadata of a map file

Now fill in the information for your map. When you get to the Scenario field, you should use the same path that you typed into the hex editor (see Figure 6-23).

Figure 6-23. Entering information about your map

Note that your map will not appear in the list on the left until you choose a Value, save, and then reopen the tag (see Figure 6-24).

Figure 6-24. The Value appears after you reopen the map

Remember to sign your modded map and the mainmenu.map file [Hack #53] before you copy the files over to your Xbox. Figure 6-25 shows a file transfer in action using CuteFTP (http://www.cuteftp.com).

Once you load the multiplayer map menu, you will see your new map added (see Figure 6-26).

If you do not sign your mainmenu.map file properly, you will not be able to start Halo 2. Instead, you will see the error "There's a problem with the disc you're using. It may be dirty or damaged. Press A to continue."

FTP? To My Xbox?

In order to FTP files over to your Xbox, you need to set it up so it's running an FTP server. This isn't as hard as it sounds: remember that you need a modded Xbox to do anything in this and later chapters (see the beginning of this chapter for more details). One of the things you get along with a modded Xbox is a replacement BIOS (there are several varieties), which is essentially an alternate operating system that your Xbox boots into. A replacement BIOS includes an FTP server that you can activate as needed. To use it, all you have to do is configure it per the instructions that came along with the mod chip. Then you need to network your PC and Xbox and use an application like CuteFTP to transfer files.

Jonathan Harbour's The Black Art of Xbox Mods (SAMS) has an explanation of how to use the Xenium O/S (an operating system that is built into the Xenium mod chip) to enable FTP on a modded Xbox.

Figure 6-25. You will need to FTP your modded files to the Xbox

Figure 6-26. The Test entry added to the list of maps