darknezz19 wrote:
why are NES so much more complicated than SNES boards><
You mean the CHR ROM, mapper, and WRAM?
Because of compromises made to keep the NES Control Deck cheap and games flexible. These include a severely undersized video RAM (for which CHR ROM and mirroring are expected to compensate) and main RAM (for which WRAM compensates), no convenient raster IRQ, no general purpose DMA, and memories that outpaced the address space.
By the Super NES era, the cost tradeoffs differed, making cartridges mostly just a ROM or two unless they include battery RAM (common) or a coprocessor (less common).