nes: axrom: support 512K oversize

This commit is contained in:
goyuken 2014-03-19 16:06:51 +00:00
parent c6a5c9b295
commit aa2fce885e
1 changed files with 7 additions and 29 deletions

View File

@ -9,8 +9,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
{ {
//configuration //configuration
bool bus_conflict; bool bus_conflict;
int vram_byte_mask; int prg_mask_32k;
int prg_mask;
//state //state
int prg; int prg;
@ -58,49 +57,28 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
return false; return false;
} }
prg_mask = (Cart.prg_size / 16) - 1; prg_mask_32k = Cart.prg_size / 32 - 1;
vram_byte_mask = 8 * 1024 - 1; //these boards always have 8KB of VRAM SetMirrorType(NES.NESBoardBase.EMirrorType.OneScreenA);
//it is necessary to write during initialization to set the mirroring
WritePRG(0, 0);
return true; return true;
} }
public override byte ReadPRG(int addr) public override byte ReadPRG(int addr)
{ {
return ROM[addr + (prg << 14)]; return ROM[addr | prg << 15];
} }
public override void WritePRG(int addr, byte value) public override void WritePRG(int addr, byte value)
{ {
if (ROM != null && bus_conflict) value = HandleNormalPRGConflict(addr,value); if (ROM != null && bus_conflict)
int prg_bank = value & 7; value = HandleNormalPRGConflict(addr,value);
prg = (prg_bank * 2) & prg_mask; prg = value & prg_mask_32k;
if ((value & 0x10) == 0) if ((value & 0x10) == 0)
SetMirrorType(NES.NESBoardBase.EMirrorType.OneScreenA); SetMirrorType(NES.NESBoardBase.EMirrorType.OneScreenA);
else else
SetMirrorType(NES.NESBoardBase.EMirrorType.OneScreenB); SetMirrorType(NES.NESBoardBase.EMirrorType.OneScreenB);
} }
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
return VRAM[addr & vram_byte_mask];
}
else return base.ReadPPU(addr);
}
public override void WritePPU(int addr, byte value)
{
if (addr < 0x2000)
{
VRAM[addr & vram_byte_mask] = value;
}
else base.WritePPU(addr,value);
}
public override void SyncState(Serializer ser) public override void SyncState(Serializer ser)
{ {
base.SyncState(ser); base.SyncState(ser);