Yeah, I have heard rumors that you can only tell from the date it was manufactured as well. I was hoping that those letters following the year/week could be deciphered to indicate whether or not I had a Dresden or Texas chip. The stain around the die is bluish on mine but I have heard recently that that doesn't necessarily mean anything. I have a pretty new chip though... 0103 to be exact... so if anyone has any idea if that indicates anything or not, please let me know.
Robin