I disassembled the japanese C64 kernal and interpreted the diffs. Only the
keyboard decoding, frame, screen and textcolor is different. They switched
the basic start to $1000 and don't use the 2kB free area!!!
I think they did it to be compatible to the VIC1001!
I modded the J64-kernal with only one byte and now it should be mostly
compatible to the western 64 (except the different char-rom)!