Articles like this, makes me warm and fuzzy all over, probably because I'm an old geezer in comparison to kids of today, but I think it's very important for anyone serious about hardware development and/or software development to dive into the past once in a while, it's a great way to learn simplicity and how the hardware inside our relatively complicated devices of today really works.
I'm a moderator of a major international electronics forum, and I don't have the number on just how many times the young generation feel completely lost when they're fresh out of school, trying to understand very complex structures. They either lack understanding of general electronics, or how the microprocessor works with different layers, ram, rom (especially embedded systems when they are working with complex IDE's with a maze of classes & libraries), they simply forget how the hardware works, and get to focus too much on programming.
I understand exactly that frustration, especially since this old geezer was lucky enough to grew up with basic home computers like the Commodore 64, Zx81 (Z80 cpu), Spectrum, Oric, Dragon 32, BBC etc. We often did our own hardware modifications, made fast I/O port load&save systems ourselves because we had a basic understanding of how the innards worked, and it really wasn't rocket science.
Sometimes it is relevant to take a step back in time (Like this article does, explaining some of the oddities with the Z80 processor), and spark interest in these old CPU's and their systems & possible uses even today. As an example, I have a HUGE stash of Micro-Controllers in my workshop, these are an absolute GEM to me. Why? Because they are very simple to work with. Like the good old Commodore 64 or ZX 81 - they don't have advanced hardware layers where you have to do special addressing to access certain memory areas or have to be kind to the operating system in order to write something to control your hardware (homemade or otherwise), it's as simple as writing a few pokes into memory...and you can turn on/off some external units such as relays, lights - or read on/off states from your sensors...maybe build your own satellite tracker the easy way, or control your homemade lawnmover unit.
And we still have VAST amounts of these MCU's unused all over the world, these are SUPER USEFUL (if you didn't get the above, think standalone apps...like each MCU was an app for a specific task). Many of these CPU's (MCU usually comes with internal memory/Ram/Rom/Flash/ and the most important part...an I/O) ready to use, just program it...and watch it go. If the kids of today understood this, they'd have a BLAST programming these (just watch the maker society with their modern versions...Arduino etc.) and the sky's the limit.
More articles like these thanks, brings /. back to the roots.