INES Mapper 088: Difference between revisions

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(reduce mapper088 docs to a reference to mapper206 and hopefully concise description of the wiring difference.)
(refile, add cat:nescartdb, also reorder the entire page to put a standard "this mapper exists because X" at the beginning)
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[[Category:iNES Mappers]][[Category:MMC3-like mappers]]
[[Category:iNES Mappers|088]][[Category:MMC3-like mappers|088]][[Category:in NesCartDB|088]]
[[iNES Mapper 088]] is the same as [[INES Mapper 206|mapper 206]] with the following exception:
* CHR support is increased to 128KB by connecting PPU's A12 line to the CHR ROM's A16 line.
 
Consequently, CHR is split into two halves. $0xxx can only have CHR from the first 64K, $1xxx can only have CHR from the second 64K.
 
A possible way to implement this would be to mask the CHR ROM 1K bank output from the mapper by ANDing with $3F, and then OR it with $40 if the PPU address was >= $1000.


   Example Games:
   Example Games:
Line 6: Line 12:
   Namcot Mahjong 3
   Namcot Mahjong 3
   Dragon Spirit - Aratanaru Densetsu
   Dragon Spirit - Aratanaru Densetsu
 
This is the same as [[INES Mapper 206|Mapper206]] with the following exception:
* CHR support is increased to 128KB by connecting PPU's A12 line to the CHR ROM's A16 line.
For example, mask the CHR ROM 1K bank output from the mapper by $3F, and then OR it with $40 if the PPU address was >= $1000.
Consequently, CHR is split into two halves. $0xxx can only have CHR from the first 64K, $1xxx can only have CHR from the second 64K.

Revision as of 20:24, 2 August 2012

iNES Mapper 088 is the same as mapper 206 with the following exception:

  • CHR support is increased to 128KB by connecting PPU's A12 line to the CHR ROM's A16 line.

Consequently, CHR is split into two halves. $0xxx can only have CHR from the first 64K, $1xxx can only have CHR from the second 64K.

A possible way to implement this would be to mask the CHR ROM 1K bank output from the mapper by ANDing with $3F, and then OR it with $40 if the PPU address was >= $1000.

 Example Games:
 --------------------------
 Quinty (J)
 Namcot Mahjong 3
 Dragon Spirit - Aratanaru Densetsu