INES Mapper 087: Difference between revisions

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(Suggestion for new development)
(m101 doesn't exist, so shouldn't be preferred.)
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   CHR, so the 'H' bit is usually unused.
   CHR, so the 'H' bit is usually unused.


[[iNES Mapper 101]] is the same but with the bits in order. [[CNROM]] (which postdates mapper 87) is the same but with the bits in order and bus conflicts.
[[iNES Mapper 101]] is the exact same board, but the bits misinterpreted as in order. [[CNROM]] (which postdates mapper 87) is the same but with the bits in order and bus conflicts.
New development should use mapper 101; those who wish to use a mapper 87 donor board can swap banks 1 and 2 of the CHR ROM.

Revision as of 20:16, 24 April 2014

 Here are Disch's original notes:  
 ========================
 =  Mapper 087          =
 ========================
 
 
 Example Games:
 --------------------------
 Argus (J)
 City Connection (J)
 Ninja Jajamaru Kun
 
 
 Notes:
 ---------------------------
 Regs are at $6000-7FFF, so these games have no SRAM.
 
 
 Registers:
 --------------------------
 
   $6000-7FFF:  [.... ..LH]
     H = High CHR Bit
     L = Low CHR Bit
 
   This reg selects 8k CHR @ $0000.  Note the reversed bit orders.  Most games using this mapper only have 16k
 CHR, so the 'H' bit is usually unused.

iNES Mapper 101 is the exact same board, but the bits misinterpreted as in order. CNROM (which postdates mapper 87) is the same but with the bits in order and bus conflicts.