BizHawk/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper62.cs

112 lines
2.2 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
public sealed class Mapper62 : NES.NESBoardBase
{
/*
Here are Disch's original notes:
========================
= Mapper 062 =
========================
Example Game:
--------------------------
Super 700-in-1
Registers:
---------------------------
$8000-FFFF: A~[..pp pppp MPOC CCCC]
[.... ..cc]
p = Low bits of PRG Reg
P = High bit of PRG Reg
c = Low bits of CHR Reg
C = High bits of CHR Reg
O = PRG Mode
M = Mirroring (0=Vert, 1=Horz)
PRG Setup:
---------------------------
$8000 $A000 $C000 $E000
+-------------------------------+
PRG Mode 0: | <$8000> |
+-------------------------------+
PRG Mode 1: | $8000 | $8000 |
+---------------+---------------+
CHR Setup:
----------------------------
'C' and 'c' select an 8k page @ $0000
*/
bool prg_mode = false;
int chr_reg;
int prg_reg;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER062":
break;
default:
return false;
}
SetMirrorType(EMirrorType.Vertical);
return true;
}
public override void SyncState(Serializer ser)
{
ser.Sync("prg_reg", ref prg_reg);
ser.Sync("chr_reg", ref chr_reg);
ser.Sync("prg_mode", ref prg_mode);
base.SyncState(ser);
}
public override void WritePRG(int addr, byte value)
{
prg_mode = addr.Bit(5);
if (addr.Bit(7))
{
SetMirrorType(EMirrorType.Horizontal);
}
else
{
SetMirrorType(EMirrorType.Vertical);
}
prg_reg = (addr & 0x40) | ((addr >> 8) & 0x3F);
chr_reg = ((addr & 0x1F) << 2) | (value & 0x03);
}
public override byte ReadPRG(int addr)
{
if (prg_mode == false)
{
return ROM[((prg_reg >> 1) * 0x8000) + addr];
}
else
{
return ROM[(prg_reg * 0x4000) + (addr & 0x3FFF)];
}
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
return VROM[(chr_reg * 0x2000) + addr];
}
return base.ReadPPU(addr);
}
}
}