You have such ponderings in common with engineers@work:

https://eaw.app/pico6502/

"and palette lookup are all DMA and PIO"

PIO is a revelation.

It's great, but I think the critique from the other day was also pretty valid. and offered an alternative.

https://www.bunniestudios.com/blog/2026/bio-the-bao-i-o-copr...

I think, for my use, just having the ability to write to DMA registers would have been a big advantage. It feels wasteful to have A DMA waiting on a FIFO just to write what it gets to DMA registers to do the transfer you actually wanted.

Looking at the Architecture diagram It seems like it could have allowed that and stayed on the same side of the AHB5 splitter.

I do love the PIO. I want to show it to a computer engineer from the 80s.