Over the past 3 years I have been teaching a unit on Computer Systems, in which I used a simple 4 Layer Model to teach how computers work. I am currently planning for next year, and whilst I am running the same unit, it will be stripped down and more focused. The 4 Layer Model has moved to v2, with some tweaks based on how I have seen students use it in previous years:

Once the unit is done I will share the whole thing here, but I just wanted to get this model up on its own for students use.