today I found out the EE UART TX pin on the system256 board
to use this UART to test for dead EE or IOP, you will need: cables (I used dupont cables female-male) and an RS232 to USB adapters (the ones that use DB9 connector)
the serial port pin is conveniently exposed on a test clamp pin near...
TC4... so you have a namco system super256. the problem with the super256 is that it has an additional 12.5% of overclock compared to regular system256 (50% compared to retail PS2), so any game that is not time crisis 4 (such as taiko drum) will sound funny and feel spedup on the super256...
Namco System256 Regional signature changer
this application overrides the iLinkID of the ps2 nvram on the system256.
This signature seems to be used only by the taiko drum games
How to use
Run the program in any way you can, make sure to run the program you really need
Regional Signatures...
The IRX archive format doesn't have any problem with changing file size
Unless the game manually checks file sizes, which would be kinda dumb bc it goes against the flexibility seeked by the format used to pack the IRX
all that was holding me back was incorrect endianess on the ATAPI sector and transfer len payload
now the game works, my not so good laptop with integrated graphics is doing 30fps stable on the attract mode...
yes, taiko developer went on and renamed the driver as acrtcilk.irx inside the archive... maybe because the only thing that driver does is get the mechacon RTC and read/write iLinkID (region signature for the sys256)
the process is simple
use the decompress script, on the generated folder...