INES Mapper 086

iNES Mapper 086 designates the JALECO-JF-13 board used for Moero!! Pro Yakyuu, the Japanese version of Jaleco's Bases Loaded.

Hardware

This board has 128 KiB PRG ROM, 64 KiB CHR ROM, no PRG RAM (the mapper ports are mapped in $6000-$7FFF instead, but that means no bus conflicts either), a 74HC139, two 74HC174s, and an additional ASIC "D7756C 148" by NEC that plays recorded speech compressed with ADPCM. An additional set of sample files is needed to emulate the sound chip.

Registers

PRG and CHR bank ($6000-$6FFF)

The PRG and CHR banking for this mapper is similar to GNROM or Color Dreams.

7654 3210
 |||   ||
 |++------ Select 32 KiB PRG bank at $8000
 +-----++- Select 8 KiB CHR bank at $0000

Audio control ($7000-$7FFF)

7654 3210
  || ||||
  || ++++- Track number
  ++------ Start/stop control

Disch thinks it's 2=start, other=stop.

Track numbers used in the game:

0	Strike
1	Ball
2	Time
3	Out
4	Safe
5	Foul ball
6	Fair ball
7	Batter out
8	Play ball
9	Ball four
10	Home run
11	New pitcher
12	Ouch (hit by pitch)
13	Fool
14	blow sound?
15	shout of joy?

References

• D7756 description and datasheet
• BBS topics 762 and 4030

 Here are Disch's original notes:  
 ========================
 =  Mapper 086          =
 ========================
 
 
 Example Games:
 --------------------------
 Moero!! Pro Yakyuu (Black)
 Moero!! Pro Yakyuu (Red)
 
 
 Notes:
 ---------------------------
 Regs are at $6000-7FFF, so these games have no SRAM.
 
 
 Registers:
 --------------------------
 
   $6000-6FFF:  [.CPP ..CC]
     P = Selects 32k PRG @ $8000
     C = Selects 8k CHR @ $0000
 
   $7000-7FFF:  [..SS IIII]  Sound control  **not sure about this**
     S = Sound Start/Stop:
                  %10 = start sound effect?
        anything else = stop sound effect?
 
     I = Sound effect ID
 
 
 Sound:
 --------------------------
 
 This mapper has some sort of sample playback mechanism.  Writing to $7xxx starts/stops the currently playing
 sample.  How this playback works (apart from the sketchy notes above) is a complete mystery to me.
 
 The sound effects themselves are NOT PART of the .nes file.  Therefore the only real way to support them
 currently would be to load external .wav files or something and play them back when they're triggered.