[0] https://eater.net/6502

I think it's still an amazing resource for anyone wanting to learn how computers work. It literally changed my life. Before I got the C64 when I was 15 years old, I had an Atari 400 and then Atari 600. There was very little available to me in the way of documentation for the Atari for anything beyond BASIC programming, and I found that very limiting. The C64 and its manual opened up a whole other world to me. I taught myself assembly programming in about a week. I got into BBSs, and eventually into the "demoscene" where I got to use all the assembly programming I learned. This built the foundation for the rest of my computing life and I wouldn't trade it for anything.

Indeed it was a golden age, when microarchitectures could really be grokked in their fullness by teenagers.

The C64 user manual was like a goldmine for me. I don't know how many supplementary materials I used (I read Compute!'s Gazette a lot) and I had already owned a VIC-20. By the time my IBM PC came along, I knew the C64 inside and out, really well. I knew the sprites subsystem and I'd programmed entire games. I knew bank switching, ROM/RAM, Kernal routines, font mapping, ASCII table, assembly and BASIC alike. I was never an electrical engineer, but I could tell you, more or less, how the 6510/6502 processed any given program and how that machine code used registers, memory, I/O, etc.

By the time I hit college I was learning Pascal and systems architecture, assembly on M68000 systems, and we were really off to the races. I was illicitly using accounts to program MU* servers and learning C, gdb, Unix. I could install and configure software and really got noticed, in my first job, for basically becoming a "shadow Unix admin" who got stuff done.

Sadly I never had the chops to be an actual IT professional or have a career. All of that knowledge and talent could've landed a career and a very stable lifestyle for someone else, but for me it was sort of an albatross. My aspirations to a corporate office job as a knowledge worker, weren't in line with what I could actually sustain.

But indeed they were golden years. I don't regret getting to know computers like that. I just wish that they had stayed as pets, rather than enslaving us like today.

It's a fair leap - all of the "indirect" instructions that do access-through-pointer stuff are zero page and would be register-oriented in most other architectures. Plus loading and storing stuff to zero page consumes the same cycles as a register (2), zero page is not slower than registers generally.

You want something really icky try to make sense of Fairchild F8 with it's 64 internal bytes of "scratchpad" RAM which are kinda halfway between registers and RAM due to the weirdness of the F8 architecture.