BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper200.cs

113 lines
2.3 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BizHawk.Emulation.Consoles.Nintendo
{
class Mapper200 : NES.NESBoardBase
{
/*
Here are Disch's original notes:
========================
= Mapper 200 =
========================
Example Games:
--------------------------
1200-in-1
36-in-1
Registers:
---------------------------
$8000-FFFF: A~[.... .... .... MRRR]
M = Mirroring (0=Vert, 1=Horz)
R = PRG/CHR Reg
CHR Setup:
---------------------------
$0000 $0400 $0800 $0C00 $1000 $1400 $1800 $1C00
+---------------------------------------------------------------+
| $8000 |
+---------------------------------------------------------------+
PRG Setup:
---------------------------
$8000 $A000 $C000 $E000
+---------------+---------------+
| $8000 | $8000 |
+---------------+---------------+
*/
int prg_reg_16k, chr_reg_8k;
int prg_bank_mask_16k;
int chr_bank_mask_8k;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER200":
case "MAPPER229":
break;
default:
return false;
}
prg_bank_mask_16k = Cart.prg_size / 16 - 1;
chr_bank_mask_8k = Cart.chr_size / 8 - 1;
return true;
}
public override void SyncState(Serializer ser)
{
ser.Sync("prg_reg_16k", ref prg_reg_16k);
ser.Sync("chr_reg_8k", ref chr_reg_8k);
base.SyncState(ser);
}
public override void WritePRG(int addr, byte value)
{
if (addr.Bit(3))
{
SetMirrorType(EMirrorType.Horizontal);
}
else
{
SetMirrorType(EMirrorType.Vertical);
}
int reg = addr & 0x07;
prg_reg_16k = reg & prg_bank_mask_16k;
chr_reg_8k = reg & chr_bank_mask_8k;
}
public override byte ReadPRG(int addr)
{
if (addr < 0x4000)
{
return ROM[(prg_reg_16k * 0x4000) + addr];
}
else
{
return ROM[(prg_reg_16k * 0x4000) + addr - 0x4000];
}
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
return VROM[(chr_reg_8k * 0x2000) + addr];
}
return base.ReadPPU(addr);
}
}
}