This is a great overview. I don't remember having to put in padding instructions to prevent the pipeline issues mentioned here; maybe we just never ran into that. (I wrote pretty much all the R3000 code for Crash 1 and just do not recall problems like that coming up.)
To us the elephant in the room limitation of PS1 is not mentioned here as far as I could tell from a quick read-through: it had no Z-buffer. This meant that you either had to do heroic pre-computation (sort polygons ahead of time) or you ended up with lots of flickering polygons (bluedino's "jiggling and sparkling" comment below seems apt).
The other thing to note is that to make a truly high-performance game for PS1 you had to completely ditch Sony's sanctioned C APIs -- something they said would cause your game to get banned, but which we did anyway. Sony's libraries spent more time copying registers to and from the stack than they did doing the actual work, so they were a big lose.
Finally, that 2KB scratchpad was immensely powerful if you used it well. It's the only reason the 3D collision detection on Crash was fast enough; it took me 9 months to get that performant enough to ship. The CPU and RAM in those machines were just incredibly slow by today's standards.
To us the elephant in the room limitation of PS1 is not mentioned here as far as I could tell from a quick read-through: it had no Z-buffer. This meant that you either had to do heroic pre-computation (sort polygons ahead of time) or you ended up with lots of flickering polygons (bluedino's "jiggling and sparkling" comment below seems apt).
The other thing to note is that to make a truly high-performance game for PS1 you had to completely ditch Sony's sanctioned C APIs -- something they said would cause your game to get banned, but which we did anyway. Sony's libraries spent more time copying registers to and from the stack than they did doing the actual work, so they were a big lose.
Finally, that 2KB scratchpad was immensely powerful if you used it well. It's the only reason the 3D collision detection on Crash was fast enough; it took me 9 months to get that performant enough to ship. The CPU and RAM in those machines were just incredibly slow by today's standards.