The PS system is all region. Hypothetically speaking. The problem I have and all other gamers out there is the region specific encryption on the games. If you are able to by pass this, you'd be able to play the game. The actual hardware of the system itself is identical to its European/Japanese counterpart, thus it will read the software you throw in the slot. The actually file on the disc are recognizable by the system itself, yet since they come out in certain REGIONS, you can't stick in a US game in a JPN system. This is the fact that the publisher encrypted the game to be RAN (USED/PLAY...whatever you want to label it as) on that specific region system. The HDD is nothing more than a HDD.
You ever try sticking a Memory Card into another PS2? It reads right? You don't need to worry about using say Freeloader, Swap Magic, or any of that stuff, because the Memory Card is NOT encrypted. I have gotten some Region 1 DVD's running on my JPN PS2, though not all of them work. Probably due to the dual-layer formatting or copyright protections.
I'll try tonight to get my US HDD (FFXI) to boot up in the JPN PS2. If I prove to be successful, I'll post some stuff in the boards. I know it can be done, because I can get region 1 DVDs working on a JPN system - knowing that JPN is a region 2 laser reading country. Also, the system itself READS my HDD and CONFIRMS FFXI being installed. I've yet to log in to see if it runs...
Again, my real problem is this:
Since FFXI Treasures of Assbaggin' (I don't know the name...sorry.) is region encoded to be played on a JPN, and since the expansion is technically readable on all PS2 systems across the board. I need to bypass the encryption files, to allow the installation.
I do know of a guy who lives not too far from me and he is Japanese and he installed a US copy of CoP on his HDD. I don't know what method or how he did it, but he can go to Promyvion and such. So, he is my proof. If you'd like I can keep you posted.