Most images you find on the net probably are already patched. If you start with a mame chd, it might not be patched.
Open the decrypted bin image in your favorite hex editor. At the beginning, it should read FATX in ascii.
Search for the ascii text XBAM. This is part of the boot.id file.
Add 0x0E to the location where you found that text. Change that byte from 0x00 into 0x01
(2 bytes further, another text should start)
So, if the XBAM starts at 0x15020 you should change the value at 0x1502e
Save the bin file and enjoy it on your chihiro 3
Open the decrypted bin image in your favorite hex editor. At the beginning, it should read FATX in ascii.
Search for the ascii text XBAM. This is part of the boot.id file.
Add 0x0E to the location where you found that text. Change that byte from 0x00 into 0x01
(2 bytes further, another text should start)
So, if the XBAM starts at 0x15020 you should change the value at 0x1502e
Save the bin file and enjoy it on your chihiro 3