The mega processor is one of my all-time favorite computers, along with the Magic-1 https://homebrewcpu.com/
The megaprocessor is just absolutely wonderful in how it bridges from 'here is a transistor, it lights an LED' to 'here is a computer, it plays tetris'. I always struggled to unwind the layers of abstraction in a modern computer from atoms in the CPU to running python, but being able to just look at a bunch of literal transistors (with LEDs on each gate!) wired up playing tetris shows how a computer really works in such a profound and awe inspiring fashion.
Magic-1 is sort of the next level higher complexity, where it is made out of very simple TTL (most complicated chip function is the ALU--a circuit I had to build as an EE undergrad out of or- and and- gates) and it hosts a webpage. It currently seems to be down, but you can see it on the wayback machine
https://web.archive.org/web/20210815180101/http://www.magic-...
I will never forget when I came across that site and realized that I was interacting with a wirewrapped pile of ram and nor gates over the internet. There was even a time when you could telnet in and play some retro text-based adventure games, To this day, the only time I have played Adventure was on Magic-1.
I'm partial to the Gigatron[0] myself. Built entirely using a mere 34 TTL ICs available in the 70s (930 logic gates) and it's capable of driving a VGA monitor and 4-bit sound while running at 6.25Mhz. In my opinion, it is beautifully simple and elegant.
Charles Petzold's book Code: The Hidden Language of Computer Hardware and Software explains a computer from the ground up.
I don't know if the ideas still apply to modern computers, but it's pretty cool understanding how things like addresses are decoded and instructions are constructed and executed at the gate level in a very basic microprocessor.
The megaprocessor is just absolutely wonderful in how it bridges from 'here is a transistor, it lights an LED' to 'here is a computer, it plays tetris'. I always struggled to unwind the layers of abstraction in a modern computer from atoms in the CPU to running python, but being able to just look at a bunch of literal transistors (with LEDs on each gate!) wired up playing tetris shows how a computer really works in such a profound and awe inspiring fashion.
Magic-1 is sort of the next level higher complexity, where it is made out of very simple TTL (most complicated chip function is the ALU--a circuit I had to build as an EE undergrad out of or- and and- gates) and it hosts a webpage. It currently seems to be down, but you can see it on the wayback machine https://web.archive.org/web/20210815180101/http://www.magic-...
I will never forget when I came across that site and realized that I was interacting with a wirewrapped pile of ram and nor gates over the internet. There was even a time when you could telnet in and play some retro text-based adventure games, To this day, the only time I have played Adventure was on Magic-1.