The in-game HDD install method is more restrictive because it will only work online with others that used the in-game install option. Note the following for using this mode:
It will not conflict with the HDL/OPL methods listed for ps2 HDD or Pcsx2 HDD. The two may co-exist as long as you have adequate space on the HDD/virtual HDD
Offline play will run from the HDD
If you create a game online, the room will be joinable by official install HDD users only unless you switch the game to DVD mode
If you attempt to join a DVD game while in HDD mode, the game will ask if you would like to change to DVD mode. If you select yes, you will be able to join the game, but will play from DVD, and for the remainder of your online session, the game will be in DVD mode. In order to switch back to HDD mode, the user would need to disconnect and reconnect, or join an HDD game.
The game options menu allows for switching between DVD and HDD mode
On a PS2 you must start the game from a DVD. You cannot boot from OPL or HD Loader and then use the game's HDD option.
As mentioned in the PS2 checklist, unless you have an official SONY HDD, you will need to patch your ISO and burn the patched ISO to a DVD.
Setup
Follow the guides for formatting the HDD for PS2 or PCSX2.
If you are on PS2 and do not have an official SONY HDD, you will need to patch an ISO to use any HDD by following the clickable instructions below. Emulator users can skip to Install.
By default, the game will only allow installation to an official SONY HDD. However, the driver can be modified to ignore this requirement. Note you will not be able to play using the original discs if you use this option, since we need to hex edit one of the files on the DVD and then play on the PS2 using a DVD backup. Your PS2 will need to be able to play backup DVDs through the use of software or hardware modification.
Credits: a July 2003 document written by Septiego / Team PS2Ownz showing the general values to change to enable use of any HDD in PS2 games. Later, Spartian Labels created a tutorial on Biohazard Dawn that demonstrated that only one value needs to be changed for File 1. Using this information I ran checksum on the relevant files in File 1 and File 2 for HDD use and determined they are the same and can be modified the same way.
Required software:
Any hex editor that you are comfortable with
Software to replace a file within an ISO. One application that can do this is Apache PS2 v1.1.
Mount your ISO File 1 or File 2 ISO. In Windows, you may right click the ISO and click Mount.
Navigate to IOP\MODULES for File 1 or MODULES for File 2.
Copy the ATAD.IRX file to anywhere on your computer.
Open ATAD.IRX in a hex editor. Search for the hex string:
D0FFBD2700210400FFFF8430
This string is present six times in the file.
Replace the last occurrence of D0FFBD2700210400FFFF8430 within the file which begins at address 0F7Ch with:
211000000800E00300000000
Before
After
Save the modified ATAD.IRX file. If you would like to verify that you modified the file correctly, check the SHA-1 checksum using a program such as 7-zip. In 7-zip right click on the file and select CRC -> SHA-1. The SHA-1 value of the modified ATAD.IRX file should be:
ef57a1b168a7dab704e9ea3221a11942e8f28314
Open the ISO in Apache and navigate to where the ATAD.IRX module is located: IOP\MODULES for File 1, and MODULES for File 2. Click on the ATAD.IRX
Click ISO Tools -> Update Selected File. Select the ATAD.IRX file that we modified with the hex editor.
The ISO is now patched. Note that you can replace ATAD.IRX with the same patched file in both File 1 and File 2. The ATAD.IRX module is the same in both. If you would like to check to make sure the file is replaced properly, use a program that can display the checksum such as 7-zip, enter your modified ISO, navigate to the ATAD.IRX file, and verify that the SHA-1 value is:
ef57a1b168a7dab704e9ea3221a11942e8f28314
Burn the modified ISO to DVD to play on PS2.
Install
Start the Outbreak game, File 1 or File 2.
In the main menu, select the HDD Install option.
The game will ask if you would like to install. Select yes.
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Now that the game is installed to HDD, HDD will be the default play mode. You may change to DVD mode in the options menu.
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