[WorldMaker]

It was impressed on me in college how much the MOS 6502 is sort of a fascinating line in the sand for a "clockwork computer". You can visualize all of the 6502 registers and all of its easily addressable RAM in a bitmap you can see on a modern screen and its general clock speeds were so much more relatively close to human scale so you could watch such a visualization compute in (near) real-time.

I remember building my own mini-6502 debugger of my own for an assignment I was having difficulty debugging on the breadboarded hardware in our lab (and also to save me from having to spend all of my waking hours in that lab). I want to say it was in something stupid like PHP at the time, but it was just a quick and dirty hacked together thing I did in like an hour during a lecture for a different class.

I've seen some really cool projects on HN of people building visual/visible 6502 boards. LEDs have gotten so cheap and the 6502 is so easy to replicate in FPGA and other hardware spaces that you can build real neat 6502 computers. Which I think the original homebrew computer club hackers would still respect all these years later. (The 6502 fueled the original home computer revolution and was in so many machines, from the Apple II to the Commodore 64 to the NES and more. It was such a key workhorse chip.) I'm still glad I had a lab course on the 6502 in my college education. (The follow up one with the Motorola 68k was maybe less successful, and mostly taught us why the 68k is the last real breadboardable CPU in so many ways including the way that it frequently burned through breadboards and made most debugging a hardware issue.)