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AndreaOrru / LaiNES

Cycle-accurate NES emulator in ~1000 lines of code
BSD 2-Clause "Simplified" License
1.49k stars 122 forks source link

Add iNes Mapper 002 (UNROM) Support #16

Closed kraln closed 7 years ago

kraln commented 7 years ago

Add support for iNES Mapper 002, which is a simpler version of Mapper 1. There is 16kB of fixed space mapped from $C000-FFFF and 16kB of mappable space from $8000-$BFFF. This space is mapped simply by writing to 0x8000. There is 8K of CHR ROM, and no RAM or anything funny.

AndreaOrru commented 7 years ago

Have you tried this on Mapper 002 games other than Contra and verified it works as expected?

kraln commented 7 years ago

I tried this with contra and with castlevania. Castlevania exhibits some strangeness with the background scrolling--not missing tiles, just strangeness. Contra's title screen is fine, but the background in the first level is totally missing. Both have issues with scrolling that is not related to the mapper.

AndreaOrru commented 7 years ago

Ok, willing to give this a try, but I'll add a line on the README about known issues.