You do not need the "cmp ebx, ..." because "sub ebx, 1" already sets the zero flag.

Thanks, I forgot about that

Also, if we're to be pedantic about the code across the article, if they used dec (directly on memory) rather than sub, in the self modifying code, they wouldn't need a load/sub/store sequence. The zero flag would still be appropriately modified.

Thanks, I forgot about dec.

There was an edge case where when the input was 0x2, it returned 0x1, that was my quick way of handling that.

Let's see, step by step, if we put 2 in EAX what happens:

Init: EBX = 2; EAX = 2;

Loop: EBX = 1;//gets decremented

CMP EBX, 1;//it's 1 so we exit

Final result is 2. Sounds the edge case is not that of an edge after all

> ; could exit at 1, but then it doesn't handle 0x2

that's a comment for another variant. For this, at beginning, it could simply stop at 1