Those first few years, with practical micro's and kits like this, I had the (mistaken) impressions that a person could learn most of it, by putting a analog scope (Tectronics 465) on the pins and BUS. Then, somebody pointed out: there were BOOKS that taught microprocessors.
Like 'The Z-80 Developer's Guide' (paraphrased title) Rodney Zak's.
Previously, I had thoughts of de-capping microprocessor ICs, to connect with internal traces (on the die). That's, maybe, illustration of how revolutionary the IC industry has been...