BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper61.cs

97 lines
1.9 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace BizHawk.Emulation.Consoles.Nintendo
{
class Mapper61 : NES.NESBoardBase
{
/*
* Here are Disch's original notes:
========================
= Mapper 061 =
========================
Example Game:
--------------------------
20-in-1
Registers:
---------------------------
$8000-FFFF: A~[.... .... M.LO HHHH]
H = High 4 bits of PRG Reg
L = Low bit of PRG Reg
O = PRG Mode
M = Mirroring (0=Vert, 1=Horz)
PRG Setup:
---------------------------
PRG Reg is 5 bits -- combination of 'H' and 'L' bits.
$8000 $A000 $C000 $E000
+-------------------------------+
PRG Mode 0: | <$8000> |
+-------------------------------+
PRG Mode 1: | $8000 | $8000 |
+---------------+---------------+
*/
public int prg_page;
public bool prg_mode;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER061":
break;
default:
return false;
}
SetMirrorType(EMirrorType.Vertical);
prg_page = 0;
prg_mode = false;
return true;
}
public override void SyncState(Serializer ser)
{
ser.Sync("prg_page", ref prg_page);
ser.Sync("prg_mode", ref prg_mode);
base.SyncState(ser);
}
public override void WritePRG(int addr, byte value)
{
if (addr.Bit(7))
{
SetMirrorType(EMirrorType.Horizontal);
}
else
{
SetMirrorType(EMirrorType.Vertical);
}
prg_mode = addr.Bit(4);
prg_page = ((addr & 0x0F) << 1) | ((addr & 0x20) >> 5);
}
public override byte ReadPRG(int addr)
{
if (prg_mode == false)
{
return ROM[((prg_page >> 1) * 0x8000) + addr];
}
else
{
return ROM[(prg_page * 0x4000) + (addr & 0x03FFF)];
}
}
}
}