I flashed a version four's console id to all zeros, once, and it's still working to this very day. Now belongs to a friend of mine. There's nothing you can do to the console id that will make it not work, exept maybe online.
The color standard output or "vmode" of the individual game is whatever it is, if you should play a pal game on an ntsc console and tv, the ps2 browser and all works till the game boots, then the game is b/w and rolls backwards at 10 fps. if your conole is diff from the tv, then it's browser wont show right, but game the same format as the tv work fine when they boot. I used to have wiring schematics that showed 2 points on every ps2's board (up to v8, after, I don't know) that when bridged with one wire, could force the console's native vmode to pal or ntsc, and that of course can be toggled with a switch, but that only changes the color output, the framerate difference remains an issue, maybe your tv can resolve it for you, but I used a vga adaptor for a long time, and it sure could't handle the forced output with a conflicting framerate. It freaked. It did take either natural vmode, though, so rigging the things was a waste of time, exept for one mod I did for a kiwi (New Zealander) who traveled to the U.S. on business a lot and wanted me to mod one of each for him, I switched the force vmode on an ntsc console whilst modding that, so it'd work on his PAL tv at home, too, and he just loved me for that, but he was the only exeption, a rare case indeed. anyway, that's a hardware mod, not really an eprom thing.
A toxic agent on a dangerous mission so secret, even I don't know what it is, because if I did, I would have to kill myself. I don't even know who's side I am on.