NES: Rainbow - mapper updates to match hardware implementation#162
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BrokeStudio wants to merge 7 commits into
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NES: Rainbow - mapper updates to match hardware implementation#162BrokeStudio wants to merge 7 commits into
BrokeStudio wants to merge 7 commits into
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removed from mapper specs
- removed PPU IRQ pending flag from returned value
The counter is already reset when writing to 0x415A (CPU IRQ control) or when it reaches 0.
- 256 bytes page - ext bank every 4 bytes
- added a sprite limit register (0-63) to update a specific amount of sprites to update - Slow OAM Update routine doesn't set $2003 anymore
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NovaSquirrel
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Jun 3, 2026
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Code looks good. I also tried checking it against the mapper documentation and it seems to match what's described there.
I noticed the least significant bit of $4151 is still documented as being an interrupt pending flag; normally I would say that a comment might be nice to indicate that the zero is meaningful (to replace the code that got removed) but if the spec effectively says that it's always zero then the meaning doesn't matter.
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Good catch, thanks, I fixed the documentation. |
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OAM Sprite Limit register described here.