If you want to learn how modern computers work, you should probably give up on the idea of building something yourself - since any modern architecture relies on busses, peripherals and processor functionality that are way beyond hand soldered kits. Get a Raspberry Pi and accept that even light switches run Linux these days!
More seriously, since the time of 8-bit CPUs, hardware has essentially split into deeply embedded system on chip designs (often ARM or RiscV cores) or monster multi-core 64 bit CPUs. The intervening 16 and 32 bit processors have largely been consigned to history (genuinely a shame - but that's the reason there are so few kits based on them). Ironically, it's the old Z80 and 6502 that are still being manufactured today in volume and at low cost as a convenient building block for simple "computer" devices.
So, no - this sort of kit does not teach you how your M3 Mac works - but it does provide you with a system that you can completely understand and control, that you can build your own peripherals for, that you can write a complete operating system for, or games and programs, that you can have the satisfaction of building yet still has the basic architecture of any modern computer. And for the sort of task you're likely to undertake, it's surprisingly capable.
Alternatively, if you want hardware with a simple programming model that abstracts the difficult stuff away, get an Arduino. That's really the choice you're making - either 'close to the metal' coding on older CPUs, or the modern approach of abstracting everything into software. Both are equally valid.
Thank you for your kind words. I'm the guy behind MicroBeast - and yes, you're right that video is hard.
However, I'm working on it! VideoBeast is a video 'chip' that I hope solves some of the problems with getting decent graphics out of 8-bit retro and homebrew computers.
* It has a high bandwidth interface, acting like a (paged) RAM chip that should be compatible with most 8-bit CPUs.
* It outputs a digital video signal that can be easily connected with modern monitors.
* It supports text, bitmaps, tile maps and sprites and composites them in up to six layers.
* It has a large (1Mb) video ram to support full screen graphics, and provides an SD-Card interface to load data efficiently either for display or the host CPU to read.
* It supports the features used in many late 80's arcade boards that allow a relatively slow CPU to move large graphics around on screen, including hardware scrolling, palette effects, raster timing, windowing and transparency.
Whilst there are designs out there that do this with TTL logic, for reasons of cost and sanity the design is FPGA based - I'm working hard to use the lowest cost device to do the maximum amount of work, whilst taking nothing away from the host CPU. VideoBeast acts like an old school Video Display Processor, with memory mapped graphics, not a co-processor pretending to be a graphics device.
I think this is a far better solution than a Pi or ESP32 on a serial bus (slow to update and restricted by on-board RAM), and it should reasonably outperform the X16 thanks to an architecture that centres on efficient and flexible memory access.
There are some more details linked from the MicroBeast page. I've got the prototype units running currently and will be sharing more demos and information over the next few months as it approaches feature complete. There's a way to go yet, but I think this is going to be pretty exciting.
More seriously, since the time of 8-bit CPUs, hardware has essentially split into deeply embedded system on chip designs (often ARM or RiscV cores) or monster multi-core 64 bit CPUs. The intervening 16 and 32 bit processors have largely been consigned to history (genuinely a shame - but that's the reason there are so few kits based on them). Ironically, it's the old Z80 and 6502 that are still being manufactured today in volume and at low cost as a convenient building block for simple "computer" devices.
So, no - this sort of kit does not teach you how your M3 Mac works - but it does provide you with a system that you can completely understand and control, that you can build your own peripherals for, that you can write a complete operating system for, or games and programs, that you can have the satisfaction of building yet still has the basic architecture of any modern computer. And for the sort of task you're likely to undertake, it's surprisingly capable.
Alternatively, if you want hardware with a simple programming model that abstracts the difficult stuff away, get an Arduino. That's really the choice you're making - either 'close to the metal' coding on older CPUs, or the modern approach of abstracting everything into software. Both are equally valid.