There seems to be a misunderstanding what fields those learning architectures are geared towards. They are usually not for learning about application or even s

There seems to be a misunderstanding what fields those learning architectures are geared towards. They are usually not for learning about application or even systems programming, in assembly and otherwise. They are about CPU architectures (and some surrounding concepts) themselves. The goal is to be able to quickly build your own emulator/simulator (like the VM behind the link), and maybe an assembler. Or, coming from the other side, given a working emulator/simulator, implement a high level language compiler, such as for a simplified C language. In both those goals the CPU architecture is geared towards quickly converging towards a working system. So of course they don't require you to implement (as someone learning architecture engineering) or even use (as someone learning to build a compiler) an entire MMU, much like your first project car likely wouldn't contain a computerized double clutch transmission. Instead, they are simplified CPU architectures that allow you to make steady progress, without being slowed down by the tedious complexity that a real architecture brings for reasons that are not relevant yet when starting out. Then, once that is achieved, you can freely add things like an MMU, a cache controller, maybe shift towards a pipelined or even superscalar architectures... Besides, a very large class of computers don't have many of the things that you mentioned. For one, even very advanced microcontrollers explicitly don't even have an MMU, because that would destroy latency guarantees (very bad for automative controllers). For the rest, I've got to say that there is a certain irony in complaining that computer architecture students don't know about "modern computers", while in the same breath mentioning things like INT 15h, segmentation, and x86 PITs, as if we were in the 1990s.