As you know, normally the country code is set in $1F0 in three bytes. In those three bytes you have to specify the following letters, one for each region, and leave unused bytes as spaces: J: Japan U: America E: Europe However, in the Technicall Bulletin #31, Sega suggests a new method for country codes. In this method one byte is always used. You must make a four bit value based on the allowed regions, and put it at $1F0 as a hexadecimal value in ASCII (watch out with that, don't put the value straight as it is). Bit 0: Domestic, NTSC (Japan) Bit 1: Domestic, PAL (Invalid?) Bit 2: Overseas, NTSC (America) Bit 3: Overseas, PAL (Europe) The point is, which method do you prefer? The old one or the new one? Yes, this is a poll. Just to see if we want to change our standard for setting that or not. I plan to implement checking for both method in the 2gen BIOS (if I continue working on it ), by the way. You choose.