As it is well known, Alternate Reality The City is one of the heaviest copy protected titles for the Atari 8-bits. At the hardware side of the protection, it was one of the first titles that had weak bits. It has several sectors of weak bits on the same track. It is rather unique in that it combines both duplicate sectors and sectors with weak bits (it has dups of weak sectors). It is very strict when it checks the extent of the weak bits in the sector. And it has other, more common, protections as well. Philip Price at his best
Recently we found that there is a version that doesn't have any weak bits at all. The track with the weak bits is identical except that the sectors instead of weak bits they are "stable" with a "normal" CRC error. As if that track would have been copied with something like a Happy that can't reproduce weak bits. The rest of the protection was not altered. My initial reaction was that it was either a duplication defect or a hacked version. But now we found multiple copies of this version, they all match and are identical. That would mean it is very unlikely it is a hack. And the code was altered to ignore the result of the protection checking for the weak bits. Or at least it seems so. That would discard a mastering or duplication defect. The check for the "common" protection remains. It is still copy protected.
I don't know why they removed the weak bits. A possible idea is that at some point they used cheaper duplication that couldn't master the weak bits.
Regardless it would be important if we can confirm that this version works correctly. Unfortunately it is very difficult for this type of games. If somebody very familiar with this game would like to test it, please let me know and I'll send you images of this version.
For the time being, until confirming the exact behavior of this version I would prefer to avoid a public post. But we are not hiding it either. If somebody wants the images right now, just ask.