INES Mapper 154: Difference between revisions

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m (i'm on crack, there's no way there can be bus conflicts when the n108 disables the prg on writes.)
m (do the same simplification to the description that we did to m88)
Line 1: Line 1:
[[Category:iNES Mappers]][[Category:MMC3-like mappers]]
[[Category:iNES Mappers]][[Category:MMC3-like mappers]]
Looking at [http://bootgod.dyndns.org:7777/profile.php?id=3837 bootgod's db], it looks like the M bit might be present in both $8000 and $8001 registers, but I can't be certain from the pictures.
[[iNES Mapper 154]] represents '''NAMCOT-3453''', a board used only for the game Devil Man.


  Here are Disch's original notes: 
It is identical to [[iNES Mapper 088|Mapper 88]], except with the addition of a single bit allowing for mapper-controlled one-screen mirroring:
  ========================
 
  =  Mapper 154          =
   $8000-$FFFF: [.Mxx xxxx]
  ========================
     x = See [[iNES Mapper 206|mapper 206]] documentation
 
    M = Mirroring
  Example Game:
      0 = 1ScA
  --------------------------
      1 = 1ScB
  Devil Man
 
 
Note that this bit is present over the entire 32kB range; it is not present in only odd or even addresses unlike the associated Namcot 108.
 
 
 
Like mapper 88, content in the left pattern table ($0xxx) comes from the first 64kB of CHR-ROM and content in the right pattern table ($1xxx) comes from the last 64kB of CHR-ROM.
  Registers:
  ---------------------------
 
  Range,Mask:   $8000-FFFF, $8001
 
 
     $8000:  [.M.. .AAA]
      M = Mirroring
        0 = 1ScA
        1 = 1ScB
      A = Address for use with $8001
 
 
    $8001:  [DDDD DDDD]
      Data port:
        R:0 ->  CHR reg 0
        R:1 ->  CHR reg 1
        R:2 ->  CHR reg 2
        R:3 ->  CHR reg 3
        R:4 ->  CHR reg 4
        R:5 ->  CHR reg 5
        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:0>    |    <R:1>    |  R:2  |  R:3  |  R:4  |  R:5  |
      +---------------+---------------+-------+-------+-------+-------+
 
  R:0,R:1  select CHR from the first 64k block.  R:2-R:5 select CHR from the second 64k block.
 
  Therefore, you must effectively AND the written values to R:0,R:1 with $3F, and OR the written values to
  R:2-R:5 with $40.
 
 
  PRG Setup:
  ---------------------------
 
        $8000  $A000  $C000  $E000 
      +-------+-------+-------+-------+
      |  R:6  |  R:7  | { -2} | { -1} |
      +-------+-------+-------+-------+

Revision as of 01:38, 16 July 2012

iNES Mapper 154 represents NAMCOT-3453, a board used only for the game Devil Man.

It is identical to Mapper 88, except with the addition of a single bit allowing for mapper-controlled one-screen mirroring: 

 $8000-$FFFF: [.Mxx xxxx]
   x = See mapper 206 documentation
   M = Mirroring
     0 = 1ScA
     1 = 1ScB

Note that this bit is present over the entire 32kB range; it is not present in only odd or even addresses unlike the associated Namcot 108.

Like mapper 88, content in the left pattern table ($0xxx) comes from the first 64kB of CHR-ROM and content in the right pattern table ($1xxx) comes from the last 64kB of CHR-ROM.

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