there are 3 differences between the 520 STE and 1040 STE
1: the badge on top
2: tha label underneath (the bit that says 520 STE or 1040 STE , nothing else)
3: the fact that Atari made a lot more money out of people thinking they were getting a better computer when all it was was a 520 with 2 lot's of memory in it!