What is a XOR cursor?
Not something C=/Amiga ever used to the best of my knowledge.
XOR (or Exclusive OR) as a bitwise operation has the inherent property that if you repeat it (i.e. do it twice) it is a NULL operation.
Why do you want that? Because then you can draw and erase an image in only two operations: Doing it once will show it on the screen (and "under" already existing graphics), doing it twice undoes it.
It also has another valued property in that it only uses 2 reads(source and data) and one write operation(source) per pixel.
The classic alternative to this is the save&restore with cookie cutter approach which is
- copy data under pointer to (static) buffer (read + write)
- cookie cutter bob paste (read source + data + mask(or generate mask from data if your display/hw fits) and write source)
- restore data under pointer from buffer (read + write)
Which is a whole lot more work and time as you can see, but it looks better visually.
I believe AmigaOS used a lot of this as late as 1.1.
Commodore (since 1.2 at least - someone correct me on mousepointer details) simply worked around this by using a hw sprite for the pointer.
