INES Mapper 076: Difference between revisions

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m (Updated broken bootgod link to redirect to NESCartDB page for Megami Tensei: Digital Devil Story.)
 
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[[Category:iNES Mappers|076]][[Category:MMC3-like mappers|076]][[Category:in NesCartDB|076]]
[[Category:iNES Mappers|076]][[Category:MMC3-like mappers|076]][[Category:in NesCartDB|076]]
  This is NOT Disch's original notes:
[[iNES Mapper 076]] represents '''NAMCOT-3446''', a board used only for the game [https://nescartdb.com/profile/view/2308/megami-tensei-digital-devil-story Megami Tensei: Digital Devil Story].
  ========================
 
  =  Mapper 076         =
It rewires the [[iNES Mapper 206|Namcot 108]] mapper IC to be able to address 128 KiB of CHR, in exchange for coarser CHR banking.
  ========================
 
 
  Example Games:
  --------------------------
  Digital Devil Story - Megami Tensei
 
 
  Notes:
  ---------------------------
  This board rewires the [[iNES Mapper 206|Namcot 108]] mapper IC to increase CHR to
  128k. The trade off is coarser CHR banking.
 
  The PCB also has a [[7432]] which allows the use of a 28-pin CHR-ROM.
    
    
The PCB also has a [[7432]] which allows the use of a 28-pin CHR-ROM.
    
    
   Registers:
   Registers:
   ---------------------------
   ---------------------------
    
   Mask: $E001
  Range,Mask:   $8000-FFFF, $8001
 
    
    
     $8000:  [.... .AAA]
     $8000:  [.... .AAA]
       A = Address for use with $8001
       A = Address for use with $8001
 
    
    
     $8001:  [..DD DDDD]    Data port:
     $8001:  [..DD DDDD]    Data port:
Line 39: Line 23:
   CHR Setup:
   CHR Setup:
   ---------------------------
   ---------------------------
 
         $0000  $0400  $0800  $0C00  $1000  $1400  $1800  $1C00  
         $0000  $0400  $0800  $0C00  $1000  $1400  $1800  $1C00  
       +---------------+---------------+---------------+---------------+
       +---------------+---------------+---------------+---------------+
       |      R:2      |      R:3      |      R:4      |      R:5      |
       |      R:2      |      R:3      |      R:4      |      R:5      |
       +---------------+---------------+---------------+---------------+
       +---------------+---------------+---------------+---------------+
 
    
    
   PRG Setup:
   PRG Setup:
   ---------------------------
   ---------------------------
 
         $8000  $A000  $C000  $E000   
         $8000  $A000  $C000  $E000   
       +-------+-------+-------+-------+
       +-------+-------+-------+-------+
       |  R:6  |  R:7  | { -2} | { -1} |
       |  R:6  |  R:7  | { -2} | { -1} |
       +-------+-------+-------+-------+
       +-------+-------+-------+-------+

Latest revision as of 01:27, 14 September 2023

iNES Mapper 076 represents NAMCOT-3446, a board used only for the game Megami Tensei: Digital Devil Story.

It rewires the Namcot 108 mapper IC to be able to address 128 KiB of CHR, in exchange for coarser CHR banking.

The PCB also has a 7432 which allows the use of a 28-pin CHR-ROM.

 Registers:
 ---------------------------
 Mask: $E001
 
   $8000:  [.... .AAA]
     A = Address for use with $8001
 
   $8001:  [..DD DDDD]    Data port:
       R:2 ->  CHR reg 0  (2k @ $0000)
       R:3 ->  CHR reg 1  (2k @ $0800)
       R:4 ->  CHR reg 2  (2k @ $1000)
       R:5 ->  CHR reg 3  (2k @ $1800)
       R:6 ->  PRG reg 0  (8k @ $8000)
       R:7 ->  PRG reg 1  (8k @ $a000)
 
 CHR Setup:
 ---------------------------
       $0000   $0400   $0800   $0C00   $1000   $1400   $1800   $1C00 
     +---------------+---------------+---------------+---------------+
     |      R:2      |      R:3      |      R:4      |      R:5      |
     +---------------+---------------+---------------+---------------+
 
 PRG Setup:
 ---------------------------
       $8000   $A000   $C000   $E000  
     +-------+-------+-------+-------+
     |  R:6  |  R:7  | { -2} | { -1} |
     +-------+-------+-------+-------+