INES Mapper 209: Difference between revisions

Revision as of 15:52, 3 October 2018

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+#REDIRECT [[INES_Mapper_090]]
 {{DEFAULTSORT:209}}[[Category:INES Mappers]][[Category:Mappers with ROM nametables]][[Category:Mappers with scanline IRQs]][[Category:Mappers with cycle IRQs]]
-'''iNES Mapper 209''' refers to versions of the ASIC mapper used by [[JY Company]] where bit 5 of port $D000 switches between simple nametable control (like [[INES Mapper 090]]) and extended nametable control that allows mapping CHR ROM into nametables (like [[iNES Mapper 211]]).
-'''Mapper 209''' also seems to have a significantly different meaning to its 4K CHR banking mode (i.e. ([$D000]&$18) == $08), rather like an [[MMC4]].
-Using the terminology from [[MMC4]]:
- $A000,$9000 - Select 4 KB CHR ROM bank for PPU $0000-$0FFF used when latch 0 = $FD
- $A002,$9002 - Select 4 KB CHR ROM bank for PPU $0000-$0FFF used when latch 0 = $FE
- $A004,$9004 - Select 4 KB CHR ROM bank for PPU $1000-$1FFF used when latch 1 = $FD
- $A006,$9006 - Select 4 KB CHR ROM bank for PPU $1000-$1FFF used when latch 1 = $FE
-See also: https://forums.nesdev.org/viewtopic.php?t=15333