We know that it is possible to check the version of dreamcast looking at the number circulated on the label underneath it, but as it is a very old console many have already undergone maintenance and may have had the board changed, even have left the factory with a number that does not match the version. In the case of Brazil for example this label does not even indicate the version. Checking what is written in the GDROM is also a method that does not give you the answer entirely because you can only discard one of the three versions. The correct method to be 100% sure about the Dreamcast version is to check directly on the motherboard and there is an easy way to check this without having to dismount it completely. There are three holes under neath the board where the controls are connected, through them you will be able to see written "VA" and a number.