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REVENGE OF THE SACHEN 

QUAD KILL
This commit is contained in:
goyuken 2014-01-24 02:32:24 +00:00
parent d2f8c5b621
commit 1362c43b99
2 changed files with 305 additions and 0 deletions
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1
BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
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<SubType>Code</SubType>
</Compile>
<Compile Include="Consoles\Nintendo\NES\Boards\PxROM_FxROM.cs" />
<Compile Include="Consoles\Nintendo\NES\Boards\Sachen8259.cs" />
<Compile Include="Consoles\Nintendo\NES\Boards\SachenSimple.cs" />
<Compile Include="Consoles\Nintendo\NES\Boards\SEEPROM.cs" />
<Compile Include="Consoles\Nintendo\NES\Boards\Sunsoft1.cs" />

304
BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Sachen8259.cs Normal file
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using BizHawk.Common;
namespace BizHawk.Emulation.Cores.Nintendo.NES
{
// describes Sachen8259A/B/C. D is in a different class
// behavior from fceumm
public class Sachen8259ABC : NES.NESBoardBase
{
// config
int prg_bank_mask_32k;
int chr_bank_mask_2k;
int shiftout; // reg lines are shifted on the PCB to increase capacity
int shiftmask;
// state
int port; // register that gets written next
int prg; // 32K prg swap
int[] chr = new int[4]; // 6 bits of chr, 3 from an outer bank
bool simple; // when true, we're in some sort of "simplified" mode
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
// quite a few crappy games on these boards, shouldn't be hard to find examples?
case "MAPPER141":
case "UNIF_UNL-Sachen-8259A":
case "SACHEN-8259A":
shiftout = 1; // 256KiB chr max
break;
case "MAPPER138":
case "UNIF_UNL-Sachen-8259B":
case "SACHEN-8259B":
shiftout = 0; // 128KiB chr max
break;
case "MAPPER139":
case "UNIF_UNL-Sachen-8259C":
case "SACHEN-8259C":
shiftout = 2; // 512KiB chr max
break;
default:
return false;
}
Cart.wram_size = 0; // cart responds to regs in 6000:7fff
Cart.vram_size = 0;
shiftmask = (1 << shiftout) - 1;
prg_bank_mask_32k = Cart.prg_size / 32 - 1;
chr_bank_mask_2k = Cart.chr_size / 2 - 1;
SetMirrorType(EMirrorType.Vertical);
return true;
}
public override void WriteEXP(int addr, byte value)
{
Write(addr, value);
}
public override void WriteWRAM(int addr, byte value)
{
Write(addr, value);
}
void Write(int addr, byte value)
{
addr &= 0x0101;
if (addr == 0x100)
{
port = value & 7;
}
else
{
switch (port)
{
case 0:
case 1:
case 2:
case 3:
// low 3 bits
chr[port] &= 0x38;
chr[port] |= value & 7;
break;
case 4:
// outer bank high 3 bits
for (int i = 0; i < 4; i++)
{
chr[i] &= 0x07;
chr[i] |= (value & 7) << 3;
}
break;
case 5:
prg = value & 7;
break;
case 6: // unused?
break;
case 7:
simple = value.Bit(0);
if (simple)
{
SetMirrorType(EMirrorType.Vertical);
}
else
{
switch (value & 6)
{
case 0: SetMirrorType(EMirrorType.Vertical); break;
case 1: SetMirrorType(EMirrorType.Horizontal); break;
case 2: SetMirroring(0, 1, 1, 1); break;
case 3: SetMirrorType(EMirrorType.OneScreenA); break;
}
}
break;
}
}
}
public override byte ReadPRG(int addr)
{
int bank = prg & prg_bank_mask_32k;
return ROM[addr | bank << 15];
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
int idx = addr >> 11;
// in addition to fixing V-mirroring, simple fixes us to 1 bank
// this means for type C, simple has 1 8KiB chr bank
int bank = chr[simple ? 0 : idx];
// on the PCB, all of the CHR addr lines are shifted up,
// while the low lines that were lost are connected directly to PPU A lines
bank <<= shiftout;
bank |= idx & shiftmask;
bank &= chr_bank_mask_2k;
return VROM[addr & 0x7ff | bank << 11];
}
else
{
return base.ReadPPU(addr);
}
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("port", ref port);
ser.Sync("prg", ref prg);
ser.Sync("chr", ref chr, false);
ser.Sync("simple", ref simple);
}
}
// similar in some ways to 8259ABC, but different
// fceumm combines the code to implement them; i think that's too messy
// this mapper is stupid and was most certainly made for 1 game. it has an awkward
// chr mapping that can only support up to 32KiB chr rom, and it uses it to show
// a few famous persons portraits while playing a stupid block game
// i think there's something wrong with the mapper implementation; but the game
// sucks so hard, it's hard to tell
public class Sachen8259D : NES.NESBoardBase
{
// config
int prg_bank_mask_32k;
int chr_bank_mask_1k;
// state
int port;
int prg;
int[] chr = new int[8];
public override bool Configure(NES.EDetectionOrigin origin)
{
switch (Cart.board_type)
{
// only game i'm aware of is "The Great Wall"
case "MAPPER137":
case "UNIF_UNL-Sachen-8259D":
case "SACHEN-8259D":
break;
default:
return false;
}
Cart.wram_size = 0; // cart responds to regs in 6000:7fff
Cart.vram_size = 0;
prg_bank_mask_32k = Cart.prg_size / 32 - 1;
chr_bank_mask_1k = Cart.chr_size / 1 - 1;
// last 4k of chr is fixed
chr[4] = 0x1c;
chr[5] = 0x1d;
chr[6] = 0x1e;
chr[7] = 0x1f;
SetMirrorType(EMirrorType.Vertical);
return true;
}
public override void WriteEXP(int addr, byte value)
{
Write(addr, value);
}
public override void WriteWRAM(int addr, byte value)
{
Write(addr, value);
}
void Write(int addr, byte value)
{
addr &= 0x0101;
if (addr == 0x100)
{
port = value & 7;
}
else
{
switch (port)
{
case 0:
case 1:
case 2:
case 3:
// low 3 bits
chr[port] &= 0x18;
chr[port] |= value & 7;
break;
case 4:
// a single high bit for chr regs 1:3
// note that this bit goes in bit #4, not #3
chr[1] &= 0x0f;
chr[1] |= (value & 1) << 4;
chr[2] &= 0x0f;
chr[2] |= (value & 2) << 3;
chr[3] &= 0x0f;
chr[3] |= (value & 4) << 2;
break;
case 5:
prg = value & 7;
break;
case 6:
// one more single bit of chr for 1 reg
// so only chr[3] is 5 full bits
chr[3] &= 0x17;
chr[3] |= (value & 1) << 3;
break;
case 7:
// as in A\B\C, but we don't need to store "simple"
if (value.Bit(0))
{
SetMirrorType(EMirrorType.Vertical);
}
else
{
switch (value & 6)
{
case 0: SetMirrorType(EMirrorType.Vertical); break;
case 1: SetMirrorType(EMirrorType.Horizontal); break;
case 2: SetMirroring(0, 1, 1, 1); break;
case 3: SetMirrorType(EMirrorType.OneScreenA); break;
}
}
break;
}
}
}
public override byte ReadPRG(int addr)
{
int bank = prg & prg_bank_mask_32k;
return ROM[addr | bank << 15];
}
public override byte ReadPPU(int addr)
{
if (addr < 0x2000)
{
int bank = chr[addr >> 10] & chr_bank_mask_1k;
return VROM[addr & 0x3ff | bank << 10];
}
else
{
return base.ReadPPU(addr);
}
}
public override void SyncState(Serializer ser)
{
base.SyncState(ser);
ser.Sync("port", ref port);
ser.Sync("prg", ref prg);
ser.Sync("chr", ref chr, false);
}
}
}