158 lines
3.4 KiB
C#
158 lines
3.4 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
using System.Linq;
|
|
using System.Text;
|
|
|
|
namespace BizHawk.Emulation.Consoles.Nintendo
|
|
{
|
|
class Mapper225 : NES.NESBoardBase
|
|
{
|
|
/*
|
|
Here are Disch's original notes:
|
|
========================
|
|
= Mapper 225 =
|
|
========================
|
|
|
|
Example Games:
|
|
--------------------------
|
|
52 Games
|
|
58-in-1
|
|
64-in-1
|
|
|
|
|
|
Registers:
|
|
---------------------------
|
|
|
|
$5800-5803: [.... RRRR] RAM (readable/writable)
|
|
(16 bits of RAM -- 4 bits in each of the 4 regs)
|
|
$5804-5FFF: mirrors $5800-5803
|
|
|
|
$8000-FFFF: A~[.HMO PPPP PPCC CCCC]
|
|
H = High bit (acts as bit 7 for PRG and CHR regs)
|
|
M = Mirroring (0=Vert, 1=Horz)
|
|
O = PRG Mode
|
|
P = PRG Reg
|
|
C = CHR Reg
|
|
|
|
|
|
CHR Setup:
|
|
---------------------------
|
|
|
|
$0000 $0400 $0800 $0C00 $1000 $1400 $1800 $1C00
|
|
+---------------------------------------------------------------+
|
|
CHR Mode 0: | $8000 |
|
|
+---------------------------------------------------------------+
|
|
|
|
|
|
PRG Setup:
|
|
---------------------------
|
|
|
|
$8000 $A000 $C000 $E000
|
|
+-------------------------------+
|
|
PRG Mode 0: | <$8000> |
|
|
+-------------------------------+
|
|
PRG Mode 1: | $8000 | $8000 |
|
|
+---------------+---------------+
|
|
*/
|
|
|
|
bool prg_mode = false;
|
|
int chr_reg;
|
|
int prg_reg;
|
|
ByteBuffer eRAM = new ByteBuffer(4);
|
|
int chr_bank_mask_8k, prg_bank_mask_16k, prg_bank_mask_32k;
|
|
|
|
public override bool Configure(NES.EDetectionOrigin origin)
|
|
{
|
|
switch (Cart.board_type)
|
|
{
|
|
case "MAPPER225":
|
|
break;
|
|
default:
|
|
return false;
|
|
}
|
|
chr_bank_mask_8k = Cart.chr_size / 8 - 1;
|
|
prg_bank_mask_16k = Cart.prg_size / 16 - 1;
|
|
prg_bank_mask_32k = Cart.prg_size / 32 - 1;
|
|
|
|
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);
|
|
ser.Sync("eRAM", ref eRAM);
|
|
base.SyncState(ser);
|
|
}
|
|
|
|
public override void Dispose()
|
|
{
|
|
eRAM.Dispose();
|
|
base.Dispose();
|
|
}
|
|
|
|
public override void WritePRG(int addr, byte value)
|
|
{
|
|
addr += 0x8000;
|
|
prg_mode = addr.Bit(12);
|
|
if (addr.Bit(13))
|
|
{
|
|
SetMirrorType(EMirrorType.Horizontal);
|
|
}
|
|
else
|
|
{
|
|
SetMirrorType(EMirrorType.Vertical);
|
|
}
|
|
|
|
int high = (addr & 0x4000) >> 8;
|
|
prg_reg = (addr >> 6) & 0x3F | high;
|
|
chr_reg = addr & 0x3F | high;
|
|
}
|
|
|
|
public override byte ReadPRG(int addr)
|
|
{
|
|
if (prg_mode == false)
|
|
{
|
|
int bank = (prg_reg >> 1) & prg_bank_mask_32k;
|
|
return ROM[(bank * 0x8000) + addr];
|
|
}
|
|
else
|
|
{
|
|
return ROM[((prg_reg & prg_bank_mask_16k) * 0x4000) + (addr & 0x3FFF)];
|
|
}
|
|
}
|
|
|
|
public override byte ReadPPU(int addr)
|
|
{
|
|
if (addr < 0x2000)
|
|
{
|
|
return VROM[((chr_reg & chr_bank_mask_8k) * 0x2000) + addr];
|
|
}
|
|
return base.ReadPPU(addr);
|
|
}
|
|
|
|
public override void WriteEXP(int addr, byte value)
|
|
{
|
|
if (addr >= 0x1800)
|
|
{
|
|
eRAM[(addr & 0x07)] = (byte)(value & 0x0F);
|
|
}
|
|
}
|
|
|
|
public override byte ReadEXP(int addr)
|
|
{
|
|
if (addr >= 0x1800)
|
|
{
|
|
return eRAM[(addr & 0x07)];
|
|
}
|
|
else
|
|
{
|
|
return base.ReadEXP(addr);
|
|
}
|
|
}
|
|
}
|
|
}
|