One thing that really helped me was getting a circuit diagram for a simple 8 bit computer, and then creating a memory map by tracing the address lines and writing what numbers were needed to enable addressing or not. Uh, I've done a really poor job of explaining this. Wikipedia does slightly better - (http://en.wikipedia.org/wiki/Memory-mapped_I/O) but there must be something even better than that.
These slides have the limitation of being slides, but they seem (at first glance) to be pretty good.
(http://www.charlespetzold.com/code/)
Or the Art of Electronics Student Manual, which goes through the process of building a computer.
(http://www.amazon.co.uk/The-Art-Electronics-Student-Manual/d...)
One thing that really helped me was getting a circuit diagram for a simple 8 bit computer, and then creating a memory map by tracing the address lines and writing what numbers were needed to enable addressing or not. Uh, I've done a really poor job of explaining this. Wikipedia does slightly better - (http://en.wikipedia.org/wiki/Memory-mapped_I/O) but there must be something even better than that.
These slides have the limitation of being slides, but they seem (at first glance) to be pretty good.
(http://research.cs.tamu.edu/prism/lectures/mbsd/mbsd_l16.pdf)