INES Mapper 093

This is part of a family of Sunsoft mappers used largely by Japanese games: (iNES Mapper 089, iNES Mapper 093, iNES Mapper 184)

This mapper is used by Shanghai (J) which uses the Sunsoft-2 IC on the Sunsoft-3R board, as well as Fantasy Zone (J) which was programmed to work on both the Sunsoft-3R board and a different one that used the Sunsoft-1 IC (see Mapper 184 for more information). Mapper 089 uses the same Sunsoft-2 IC but on the Sunsoft-3 board and so differs in that it has mapper-controlled one-screen mirroring and CHR ROM banking.

Here is the documentation in disch's original style:

 Registers:
 --------------------------
 No bus conflicts.
   
   $8000-FFFF:  [.PPP ...E]
     P = PRG Reg  (16k @ $8000)
     E = CHR RAM enable (write 1 here for normal operation)
 
 
 PRG Setup:
 --------------------------
 
       $8000   $A000   $C000   $E000  
     +---------------+---------------+
     |     $8000     |     { -1}     |
     +---------------+---------------+