On the other hand, architecture back then was pretty simple though. Plus there is a big OS in middle of everything, you cannot really talk to the hardware direc

On the other hand, architecture back then was pretty simple though. Plus there is a big OS in middle of everything, you cannot really talk to the hardware directly nowadays. Back in the Apple ][ and DOS days it was mandatory. That's why I have always been thinking that people actually should still start from an Apple ][/C64/80286/NES/SNES/GB these days, or maybe just embedded system for cheaper introductory tuition/quicker employment. You ignore all bells and whistles of hardware accumulated through the last 30 or so years and start from bare metal, real mode and gradually crawl from there. But without ignoring the bells and whistles of software tools people built for these platforms. I bet nowadays we have better tools for developing on these platforms. As some other commenter said, we can spin up a VM or emulator and directly look at memory and registers.