A related processor is the Motorola 68000, the processor used on the original Macintosh computer, as well as the Commodore Amiga. A simulator is available at http://www.easy68k.com. There might also be one for the 6800.I was thinking that a discussion using the 6800 cpu might help in this thread since it had memory mapped io which eliminates some complexity from the discussion.
I'm teaching a class Intro to Computer Architecture, starting in a week. Along with the architecture stuff, students write a number of short assembly programs using a simulator for the MIPS 32-bit processor. Due to the regularity of its instruction set, assembly language is much easier to learn than, say, the Intel x86 processors. There are a couple of simulators for MIPS - QtSpim (https://sourceforge.net/projects/spimsimulator/files/) and MARS (https://courses.missouristate.edu/KenVollmar/mars/download.htm). Both allow you to single-step through a program so you can see how the registers, stack, and other memory change.
It might be too long for an Insights article. The recommended length is ~800 words, although I have exceeded that limit several times. If one could fit a summary into an article, it would have to be very sparing on any details.But im still thinking about how to summarize it in a post even though we know there is so much more to how a computer actually works. It might make a good insight article though.