Yes, the O/P should have said more, but, if his question is, "How do I decode a memory address in a memory system?" which IS what he asked, isn't that enough? It doesn't require that it be for an 805x, though it wouldn't surprise me to see responses that are 805x-specific.

I'd suggest that we all focus on the question and the appropriate way of addressing it, rather than creating all the noise about how to avoid it.

RE