BizHawk/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/IC_74x377.cs

96 lines
2.2 KiB
C#

using System;
using System.IO;
using System.Diagnostics;
namespace BizHawk.Emulation.Consoles.Nintendo
{
//mapper 011
//Crystal Mines
//Metal Fighter
public class IC_74x377 : NES.NESBoardBase
{
//configuration
int prg_bank_mask_32k, chr_bank_mask_8k;
bool bus_conflict = true;
bool bus_conflict_50282 = false;
//state
int prg_bank_32k, chr_bank_8k;
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
case "MAPPER011":
break;
case "Discrete_74x377-FLEX":
break;
case "COLORDREAMS-74*377":
AssertPrg(32,64,128); AssertChr(16,32,64,128); AssertVram(0); AssertWram(0);
break;
case "AGCI-50282": // death race
case "MAPPER144":
bus_conflict_50282 = true;
bus_conflict = false;
SetMirrorType(Cart.pad_h, Cart.pad_v);
break;
default:
return false;
}
prg_bank_mask_32k = Cart.prg_size / 32 - 1;
chr_bank_mask_8k = Cart.chr_size / 8 - 1;
return true;
}
public override byte ReadPRG(int addr)
{
return ROM[addr + (prg_bank_32k << 15)];
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
return VROM[addr + (chr_bank_8k << 13)];
}
else return base.ReadPPU(addr);
}
public override void WritePRG(int addr, byte value)
{
if (bus_conflict_50282)
{
// this is what fceux does
//if (addr == 0)
// return;
// this is what nesdev wiki does. seems to give same results as above?
value = (byte)((value | 1) & ReadPRG(addr));
}
if (bus_conflict)
{
byte old_value = value;
value &= ReadPRG(addr);
//Bible Adventures (Unl) (V1.3) [o1].nes will exercise this bus conflict, but not really test it. (works without bus conflict emulation
Debug.Assert(old_value == value, "Found a test case of Discrete_74x377 bus conflict. please report.");
}
prg_bank_32k = (value & 3) & prg_bank_mask_32k;
chr_bank_8k = ((value >> 4) & 0xF) & chr_bank_mask_8k;
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("prg_bank_32k", ref prg_bank_32k);
ser.Sync("chr_bank_8k", ref chr_bank_8k);
}
}
}