Pole Position for the Spectrum came out originally in May 1984 under the Atari label. But with the 'new look' Atari, they lost the licence from Namco for Pole Position. So Datasoft ended up with the game rights to Pole Position instead.
So, to cut a very long story short, US Gold have ended up with the Datasoft version of the game. The only difference between the two versions is that the signs on them are different. One says 'Datasoft' a lot and the other says 'Atari' a lot.
Otherwise the game is straight Pole Position. The Spectrum version is one of the better versions that came out. The C64 version, for instance, was awful - but that was written in America, and the Spectrum version was written over here.
Another 'Golden Oldie' that is hitting the shelves again and well worth it it is too. Pole Position strikes the right balance between action and simulation; that makes it much better to play. An Amstrad version of the game is due soon too.