path: root/source/ppu.c

#include "../copyright"

#include "snes9x.h"
#include "memmap.h"
#include "ppu.h"
#include "cpuexec.h"
#include "missing.h"
#include "apu.h"
#include "dma.h"
#include "display.h"
#include "sa1.h"
#include "sdd1.h"
#include "srtc.h"
#include "spc7110.h"

#include "fxemu.h"
#include "fxinst.h"
extern struct FxInit_s SuperFX;
extern uint8_t mul_brightness [16][32];

uint32_t justifiers = 0xFFFF00AA;
uint8_t in_bit = 0;

extern uint8_t* HDMAMemPointers [8];

void S9xLatchCounters(bool force)
{
   if (!force && !(Memory.FillRAM[0x4213] & 0x80)) return;

   PPU.HVBeamCounterLatched = 1;
   PPU.VBeamPosLatched = (uint16_t) CPU.V_Counter;
   PPU.HBeamPosLatched = (uint16_t)((CPU.Cycles * SNES_HCOUNTER_MAX) /
                                  Settings.H_Max);

   Memory.FillRAM [0x213F] |= 0x40;
}

void S9xUpdateJustifiers();

void S9xUpdateHTimer()
{
   if (PPU.HTimerEnabled)
   {
      PPU.HTimerPosition = PPU.IRQHBeamPos * Settings.H_Max / SNES_HCOUNTER_MAX;
      if (PPU.HTimerPosition == Settings.H_Max ||
            PPU.HTimerPosition == Settings.HBlankStart)
         PPU.HTimerPosition--;

      if (!PPU.VTimerEnabled || CPU.V_Counter == PPU.IRQVBeamPos)
      {
         if (PPU.HTimerPosition < CPU.Cycles)
         {
            // Missed the IRQ on this line already
            if (CPU.WhichEvent == HBLANK_END_EVENT ||
                  CPU.WhichEvent == HTIMER_AFTER_EVENT)
            {
               CPU.WhichEvent = HBLANK_END_EVENT;
               CPU.NextEvent = Settings.H_Max;
            }
            else
            {
               CPU.WhichEvent = HBLANK_START_EVENT;
               CPU.NextEvent = Settings.HBlankStart;
            }
         }
         else
         {
            if (CPU.WhichEvent == HTIMER_BEFORE_EVENT ||
                  CPU.WhichEvent == HBLANK_START_EVENT)
            {
               if (PPU.HTimerPosition > Settings.HBlankStart)
               {
                  // HTimer was to trigger before h-blank start,
                  // now triggers after start of h-blank
                  CPU.NextEvent = Settings.HBlankStart;
                  CPU.WhichEvent = HBLANK_START_EVENT;
               }
               else
               {
                  CPU.NextEvent = PPU.HTimerPosition;
                  CPU.WhichEvent = HTIMER_BEFORE_EVENT;
               }
            }
            else
            {
               CPU.WhichEvent = HTIMER_AFTER_EVENT;
               CPU.NextEvent = PPU.HTimerPosition;
            }
         }
      }
   }
}

void S9xFixColourBrightness()
{
   IPPU.XB = mul_brightness [PPU.Brightness];
   int32_t i;
   for (i = 0; i < 256; i++)
   {
      IPPU.Red [i] = IPPU.XB [PPU.CGDATA [i] & 0x1f];
      IPPU.Green [i] = IPPU.XB [(PPU.CGDATA [i] >> 5) & 0x1f];
      IPPU.Blue [i] = IPPU.XB [(PPU.CGDATA [i] >> 10) & 0x1f];
      IPPU.ScreenColors [i] = BUILD_PIXEL(IPPU.Red [i], IPPU.Green [i],
                                          IPPU.Blue [i]);
   }
}

static void S9xSetSuperFX(uint8_t Byte, uint16_t Address)
{
   uint8_t old_fill_ram;
   if (!Settings.SuperFX)
      return;

   old_fill_ram = Memory.FillRAM[Address];
   Memory.FillRAM[Address] = Byte; 

   switch (Address)
   {
      case 0x3030:
         if ((old_fill_ram ^ Byte) & FLG_G)
         {
            Memory.FillRAM [Address] = Byte;
            // Go flag has been changed
            if (Byte & FLG_G)
               S9xSuperFXExec();
            else
               FxFlushCache();
         }
         break;

      case 0x3031:
      case 0x3033:
      case 0x3037:
      case 0x3039:
      case 0x303a:
      case 0x303f:
         break;
      case 0x3034:
      case 0x3036:
         Memory.FillRAM [Address] &= 0x7f;
         break;
      case 0x3038:
         fx_dirtySCBR();
         break;
      case 0x303b:
         break;
      case 0x303c:
         fx_updateRamBank(Byte);
         break;
      case 0x301f:
         Memory.FillRAM [0x3000 + GSU_SFR] |= FLG_G;
         S9xSuperFXExec();
         break;

      default:
         if (Address >= 0x3100)
            FxCacheWriteAccess(Address);
         break;
   }
}

/******************************************************************************/
/* S9xSetPPU()                                                                */
/* This function sets a PPU Register to a specific byte                       */
/******************************************************************************/
void S9xSetPPU(uint8_t Byte, uint16_t Address)
{
   if (Address <= 0x2183)
   {
      switch (Address)
      {
      case 0x2100:
         // Brightness and screen blank bit
         if (Byte != Memory.FillRAM [0x2100])
         {
            FLUSH_REDRAW();
            if (PPU.Brightness != (Byte & 0xF))
            {
               IPPU.ColorsChanged = true;
               IPPU.DirectColourMapsNeedRebuild = true;
               PPU.Brightness = Byte & 0xF;
               S9xFixColourBrightness();
               if (PPU.Brightness > IPPU.MaxBrightness)
                  IPPU.MaxBrightness = PPU.Brightness;
            }
            if ((Memory.FillRAM[0x2100] & 0x80) != (Byte & 0x80))
            {
               IPPU.ColorsChanged = true;
               PPU.ForcedBlanking = (Byte >> 7) & 1;
            }
         }
         break;

      case 0x2101:
         // Sprite (OBJ) tile address
         if (Byte != Memory.FillRAM [0x2101])
         {
            FLUSH_REDRAW();
            PPU.OBJNameBase   = (Byte & 3) << 14;
            PPU.OBJNameSelect = ((Byte >> 3) & 3) << 13;
            PPU.OBJSizeSelect = (Byte >> 5) & 7;
            IPPU.OBJChanged = true;
         }
         break;

      case 0x2102:
         // Sprite write address (low)
         PPU.OAMAddr = ((Memory.FillRAM[0x2103] & 1) << 8) | Byte;
         PPU.OAMFlip = 2;
         PPU.OAMReadFlip = 0;
         PPU.SavedOAMAddr = PPU.OAMAddr;
         if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
         {
            PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
            IPPU.OBJChanged = true;
         }
         break;

      case 0x2103:
         // Sprite register write address (high), sprite priority rotation
         // bit.
         PPU.OAMAddr = ((Byte & 1) << 8) | Memory.FillRAM[0x2102];

         PPU.OAMPriorityRotation = (Byte & 0x80) ? 1 : 0;
         if (PPU.OAMPriorityRotation)
         {
            if (PPU.FirstSprite != (PPU.OAMAddr >> 1))
            {
               PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
               IPPU.OBJChanged = true;
            }
         }
         else
         {
            if (PPU.FirstSprite != 0)
            {
               PPU.FirstSprite = 0;
               IPPU.OBJChanged = true;
            }
         }
         PPU.OAMFlip = 0;
         PPU.OAMReadFlip = 0;
         PPU.SavedOAMAddr = PPU.OAMAddr;
         break;

      case 0x2104:
         // Sprite register write
         REGISTER_2104(Byte);
         break;

      case 0x2105:
         // Screen mode (0 - 7), background tile sizes and background 3
         // priority
         if (Byte != Memory.FillRAM [0x2105])
         {
            FLUSH_REDRAW();
            PPU.BG[0].BGSize = (Byte >> 4) & 1;
            PPU.BG[1].BGSize = (Byte >> 5) & 1;
            PPU.BG[2].BGSize = (Byte >> 6) & 1;
            PPU.BG[3].BGSize = (Byte >> 7) & 1;
            PPU.BGMode = Byte & 7;
            // BJ: BG3Priority only takes effect if BGMode==1 and the bit is set
            PPU.BG3Priority  = ((Byte & 0x0f) == 0x09);
            if (PPU.BGMode == 5 || PPU.BGMode == 6)
               IPPU.Interlace = Memory.FillRAM[0x2133] & 1;
         }
         break;

      case 0x2106:
         // Mosaic pixel size and enable
         if (Byte != Memory.FillRAM [0x2106])
         {
            FLUSH_REDRAW();
            PPU.Mosaic = (Byte >> 4) + 1;
            PPU.BGMosaic [0] = (Byte & 1) && PPU.Mosaic > 1;
            PPU.BGMosaic [1] = (Byte & 2) && PPU.Mosaic > 1;
            PPU.BGMosaic [2] = (Byte & 4) && PPU.Mosaic > 1;
            PPU.BGMosaic [3] = (Byte & 8) && PPU.Mosaic > 1;
         }
         break;
      case 0x2107:    // [BG0SC]
      case 0x2108:    // [BG1SC]
      case 0x2109:    // [BG2SC]
      case 0x210A:    // [BG3SC]
         if (Byte != Memory.FillRAM [Address])
         {
            FLUSH_REDRAW();
            PPU.BG[Address - 0x2107].SCSize = Byte & 3;
            PPU.BG[Address - 0x2107].SCBase = (Byte & 0x7c) << 8;
         }
         break;

      case 0x210B:    // [BG01NBA]
         if (Byte != Memory.FillRAM [0x210b])
         {
            FLUSH_REDRAW();
            PPU.BG[0].NameBase    = (Byte & 7) << 12;
            PPU.BG[1].NameBase    = ((Byte >> 4) & 7) << 12;
         }
         break;

      case 0x210C:    // [BG23NBA]
         if (Byte != Memory.FillRAM [0x210c])
         {
            FLUSH_REDRAW();
            PPU.BG[2].NameBase    = (Byte & 7) << 12;
            PPU.BG[3].NameBase    = ((Byte >> 4) & 7) << 12;
         }
         break;


      //This is the Theme Park fix - it appears all these registers
      //share a previous byte value for setting them.

      case 0x210D:
         PPU.BG[0].HOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x210E:
         PPU.BG[0].VOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x210F:
         PPU.BG[1].HOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x2110:
         PPU.BG[1].VOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x2111:
         PPU.BG[2].HOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x2112:
         PPU.BG[2].VOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x2113:
         PPU.BG[3].HOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      case 0x2114:
         PPU.BG[3].VOffset = (Byte << 8) | PPU.BGnxOFSbyte;
         PPU.BGnxOFSbyte = Byte;
         break;

      //end Theme Park

      case 0x2115:
         // VRAM byte/word access flag and increment
         PPU.VMA.High = (Byte & 0x80) == 0 ? false : true;
         switch (Byte & 3)
         {
         case 0:
            PPU.VMA.Increment = 1;
            break;
         case 1:
            PPU.VMA.Increment = 32;
            break;
         case 2:
         case 3:
            PPU.VMA.Increment = 128;
            break;
         }
         if (Byte & 0x0c)
         {
            static uint16_t IncCount [4] = { 0, 32, 64, 128 };
            static uint16_t Shift [4] = { 0, 5, 6, 7 };
            uint8_t i = (Byte & 0x0c) >> 2;
            PPU.VMA.FullGraphicCount = IncCount [i];
            PPU.VMA.Mask1 = IncCount [i] * 8 - 1;
            PPU.VMA.Shift = Shift [i];
         }
         else
            PPU.VMA.FullGraphicCount = 0;
         break;

      case 0x2116:
         // VRAM read/write address (low)
         PPU.VMA.Address &= 0xFF00;
         PPU.VMA.Address |= Byte;
#ifdef CORRECT_VRAM_READS
         if (PPU.VMA.FullGraphicCount)
         {
            uint32_t addr = PPU.VMA.Address;
            uint32_t rem = addr & PPU.VMA.Mask1;
            uint32_t address = (addr & ~PPU.VMA.Mask1) +
                             (rem >> PPU.VMA.Shift) +
                             ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
            IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((address << 1) & 0xFFFF));
         }
         else
            IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((PPU.VMA.Address << 1) &
                                            0xffff));
#else
         IPPU.FirstVRAMRead = true;
#endif
         break;

      case 0x2117:
         // VRAM read/write address (high)
         PPU.VMA.Address &= 0x00FF;
         PPU.VMA.Address |= Byte << 8;
#ifdef CORRECT_VRAM_READS
         if (PPU.VMA.FullGraphicCount)
         {
            uint32_t addr = PPU.VMA.Address;
            uint32_t rem = addr & PPU.VMA.Mask1;
            uint32_t address = (addr & ~PPU.VMA.Mask1) +
                             (rem >> PPU.VMA.Shift) +
                             ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
            IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((address << 1) & 0xFFFF));
         }
         else
            IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((PPU.VMA.Address << 1) &
                                            0xffff));
#else
         IPPU.FirstVRAMRead = true;
#endif
         break;

      case 0x2118:
         // VRAM write data (low)
#ifndef CORRECT_VRAM_READS
         IPPU.FirstVRAMRead = true;
#endif
         REGISTER_2118(Byte);
         break;

      case 0x2119:
         // VRAM write data (high)
#ifndef CORRECT_VRAM_READS
         IPPU.FirstVRAMRead = true;
#endif
         REGISTER_2119(Byte);
         break;

      case 0x211a:
         // Mode 7 outside rotation area display mode and flipping
         if (Byte != Memory.FillRAM [0x211a])
         {
            FLUSH_REDRAW();
            PPU.Mode7Repeat = Byte >> 6;
            if (PPU.Mode7Repeat == 1)
               PPU.Mode7Repeat = 0;
            PPU.Mode7VFlip = (Byte & 2) >> 1;
            PPU.Mode7HFlip = Byte & 1;
         }
         break;
      case 0x211b:
         // Mode 7 matrix A (low & high)
         PPU.MatrixA = ((PPU.MatrixA >> 8) & 0xff) | (Byte << 8);
         PPU.Need16x8Mulitply = true;
         break;
      case 0x211c:
         // Mode 7 matrix B (low & high)
         PPU.MatrixB = ((PPU.MatrixB >> 8) & 0xff) | (Byte << 8);
         PPU.Need16x8Mulitply = true;
         break;
      case 0x211d:
         // Mode 7 matrix C (low & high)
         PPU.MatrixC = ((PPU.MatrixC >> 8) & 0xff) | (Byte << 8);
         break;
      case 0x211e:
         // Mode 7 matrix D (low & high)
         PPU.MatrixD = ((PPU.MatrixD >> 8) & 0xff) | (Byte << 8);
         break;
      case 0x211f:
         // Mode 7 centre of rotation X (low & high)
         PPU.CentreX = ((PPU.CentreX >> 8) & 0xff) | (Byte << 8);
         break;
      case 0x2120:
         // Mode 7 centre of rotation Y (low & high)
         PPU.CentreY = ((PPU.CentreY >> 8) & 0xff) | (Byte << 8);
         break;

      case 0x2121:
         // CG-RAM address
         PPU.CGFLIP = 0;
         PPU.CGFLIPRead = 0;
         PPU.CGADD = Byte;
         break;

      case 0x2122:
         REGISTER_2122(Byte);
         break;

      case 0x2123:
         // Window 1 and 2 enable for backgrounds 1 and 2
         if (Byte != Memory.FillRAM [0x2123])
         {
            FLUSH_REDRAW();
            PPU.ClipWindow1Enable [0] = !!(Byte & 0x02);
            PPU.ClipWindow1Enable [1] = !!(Byte & 0x20);
            PPU.ClipWindow2Enable [0] = !!(Byte & 0x08);
            PPU.ClipWindow2Enable [1] = !!(Byte & 0x80);
            PPU.ClipWindow1Inside [0] = !(Byte & 0x01);
            PPU.ClipWindow1Inside [1] = !(Byte & 0x10);
            PPU.ClipWindow2Inside [0] = !(Byte & 0x04);
            PPU.ClipWindow2Inside [1] = !(Byte & 0x40);
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2124:
         // Window 1 and 2 enable for backgrounds 3 and 4
         if (Byte != Memory.FillRAM [0x2124])
         {
            FLUSH_REDRAW();
            PPU.ClipWindow1Enable [2] = !!(Byte & 0x02);
            PPU.ClipWindow1Enable [3] = !!(Byte & 0x20);
            PPU.ClipWindow2Enable [2] = !!(Byte & 0x08);
            PPU.ClipWindow2Enable [3] = !!(Byte & 0x80);
            PPU.ClipWindow1Inside [2] = !(Byte & 0x01);
            PPU.ClipWindow1Inside [3] = !(Byte & 0x10);
            PPU.ClipWindow2Inside [2] = !(Byte & 0x04);
            PPU.ClipWindow2Inside [3] = !(Byte & 0x40);
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2125:
         // Window 1 and 2 enable for objects and colour window
         if (Byte != Memory.FillRAM [0x2125])
         {
            FLUSH_REDRAW();
            PPU.ClipWindow1Enable [4] = !!(Byte & 0x02);
            PPU.ClipWindow1Enable [5] = !!(Byte & 0x20);
            PPU.ClipWindow2Enable [4] = !!(Byte & 0x08);
            PPU.ClipWindow2Enable [5] = !!(Byte & 0x80);
            PPU.ClipWindow1Inside [4] = !(Byte & 0x01);
            PPU.ClipWindow1Inside [5] = !(Byte & 0x10);
            PPU.ClipWindow2Inside [4] = !(Byte & 0x04);
            PPU.ClipWindow2Inside [5] = !(Byte & 0x40);
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2126:
         // Window 1 left position
         if (Byte != Memory.FillRAM [0x2126])
         {
            FLUSH_REDRAW();
            PPU.Window1Left = Byte;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2127:
         // Window 1 right position
         if (Byte != Memory.FillRAM [0x2127])
         {
            FLUSH_REDRAW();
            PPU.Window1Right = Byte;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2128:
         // Window 2 left position
         if (Byte != Memory.FillRAM [0x2128])
         {
            FLUSH_REDRAW();
            PPU.Window2Left = Byte;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2129:
         // Window 2 right position
         if (Byte != Memory.FillRAM [0x2129])
         {
            FLUSH_REDRAW();
            PPU.Window2Right = Byte;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x212a:
         // Windows 1 & 2 overlap logic for backgrounds 1 - 4
         if (Byte != Memory.FillRAM [0x212a])
         {
            FLUSH_REDRAW();
            PPU.ClipWindowOverlapLogic [0] = (Byte & 0x03);
            PPU.ClipWindowOverlapLogic [1] = (Byte & 0x0c) >> 2;
            PPU.ClipWindowOverlapLogic [2] = (Byte & 0x30) >> 4;
            PPU.ClipWindowOverlapLogic [3] = (Byte & 0xc0) >> 6;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x212b:
         // Windows 1 & 2 overlap logic for objects and colour window
         if (Byte != Memory.FillRAM [0x212b])
         {
            FLUSH_REDRAW();
            PPU.ClipWindowOverlapLogic [4] = Byte & 0x03;
            PPU.ClipWindowOverlapLogic [5] = (Byte & 0x0c) >> 2;
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x212c:
         // Main screen designation (backgrounds 1 - 4 and objects)
         if (Byte != Memory.FillRAM [0x212c])
         {
            FLUSH_REDRAW();
            PPU.RecomputeClipWindows = true;
            Memory.FillRAM [Address] = Byte;
            return;
         }
         break;
      case 0x212d:
         // Sub-screen designation (backgrounds 1 - 4 and objects)
         if (Byte != Memory.FillRAM [0x212d])
         {
            FLUSH_REDRAW();
            PPU.RecomputeClipWindows = true;
            Memory.FillRAM [Address] = Byte;
            return;
         }
         break;
      case 0x212e:
      // Window mask designation for main screen ?
      case 0x212f:
         // Window mask designation for sub-screen ?
         if (Byte != Memory.FillRAM [Address])
         {
            FLUSH_REDRAW();
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2130:
         // Fixed colour addition or screen addition
         if (Byte != Memory.FillRAM [0x2130])
         {
            FLUSH_REDRAW();
            PPU.RecomputeClipWindows = true;
         }
         break;
      case 0x2131:
         // Colour addition or subtraction select
         if (Byte != Memory.FillRAM[0x2131])
         {
            FLUSH_REDRAW();
            // Backgrounds 1 - 4, objects and backdrop colour add/sub enable
            Memory.FillRAM[0x2131] = Byte;
         }
         break;
      case 0x2132:
         if (Byte != Memory.FillRAM [0x2132])
         {
            FLUSH_REDRAW();
            // Colour data for fixed colour addition/subtraction
            if (Byte & 0x80)
               PPU.FixedColourBlue = Byte & 0x1f;
            if (Byte & 0x40)
               PPU.FixedColourGreen = Byte & 0x1f;
            if (Byte & 0x20)
               PPU.FixedColourRed = Byte & 0x1f;
         }
         break;
      case 0x2133:
         // Screen settings
         if (Byte != Memory.FillRAM [0x2133])
         {
            if (Byte & 0x04)
            {
               PPU.ScreenHeight = SNES_HEIGHT_EXTENDED;
               if (IPPU.DoubleHeightPixels)
                  IPPU.RenderedScreenHeight = PPU.ScreenHeight << 1;
               else
                  IPPU.RenderedScreenHeight = PPU.ScreenHeight;
            }
            else PPU.ScreenHeight = SNES_HEIGHT;

            if ((Memory.FillRAM [0x2133] ^ Byte) & 3)
            {
               FLUSH_REDRAW();
               if ((Memory.FillRAM [0x2133] ^ Byte) & 2)
                  IPPU.OBJChanged = true;
               if (PPU.BGMode == 5 || PPU.BGMode == 6)
                  IPPU.Interlace = Byte & 1;
               IPPU.InterlaceSprites = 0;
            }

         }
         break;
      case 0x2134:
      case 0x2135:
      case 0x2136:
      // Matrix 16bit x 8bit multiply result (read-only)
      /* fall through */
      case 0x2137:
      // Software latch for horizontal and vertical timers (read-only)
      /* fall through */
      case 0x2138:
      // OAM read data (read-only)
      /* fall through */
      case 0x2139:
      case 0x213a:
      // VRAM read data (read-only)
      /* fall through */
      case 0x213b:
      // CG-RAM read data (read-only)
      /* fall through */
      case 0x213c:
      case 0x213d:
      // Horizontal and vertical (low/high) read counter (read-only)
      /* fall through */
      case 0x213e:
      // PPU status (time over and range over)
      /* fall through */
      case 0x213f:
         // NTSC/PAL select and field (read-only)
         return;
      case 0x2140:
      case 0x2141:
      case 0x2142:
      case 0x2143:
      case 0x2144:
      case 0x2145:
      case 0x2146:
      case 0x2147:
      case 0x2148:
      case 0x2149:
      case 0x214a:
      case 0x214b:
      case 0x214c:
      case 0x214d:
      case 0x214e:
      case 0x214f:
      case 0x2150:
      case 0x2151:
      case 0x2152:
      case 0x2153:
      case 0x2154:
      case 0x2155:
      case 0x2156:
      case 0x2157:
      case 0x2158:
      case 0x2159:
      case 0x215a:
      case 0x215b:
      case 0x215c:
      case 0x215d:
      case 0x215e:
      case 0x215f:
      case 0x2160:
      case 0x2161:
      case 0x2162:
      case 0x2163:
      case 0x2164:
      case 0x2165:
      case 0x2166:
      case 0x2167:
      case 0x2168:
      case 0x2169:
      case 0x216a:
      case 0x216b:
      case 0x216c:
      case 0x216d:
      case 0x216e:
      case 0x216f:
      case 0x2170:
      case 0x2171:
      case 0x2172:
      case 0x2173:
      case 0x2174:
      case 0x2175:
      case 0x2176:
      case 0x2177:
      case 0x2178:
      case 0x2179:
      case 0x217a:
      case 0x217b:
      case 0x217c:
      case 0x217d:
      case 0x217e:
      case 0x217f:
#ifndef USE_BLARGG_APU
#ifdef SPCTOOL
         _SPCInPB(Address & 3, Byte);
#else
         Memory.FillRAM [Address] = Byte;
         IAPU.RAM [(Address & 3) + 0xf4] = Byte;
#ifdef SPC700_SHUTDOWN
         IAPU.APUExecuting = Settings.APUEnabled;
         IAPU.WaitCounter++;
#endif
#endif // SPCTOOL
#else
         S9xAPUWritePort(Address & 3, Byte);
#endif // #ifndef USE_BLARGG_APU
         break;
      case 0x2180:
         REGISTER_2180(Byte);
         break;
      case 0x2181:
         PPU.WRAM &= 0x1FF00;
         PPU.WRAM |= Byte;
         break;
      case 0x2182:
         PPU.WRAM &= 0x100FF;
         PPU.WRAM |= Byte << 8;
         break;
      case 0x2183:
         PPU.WRAM &= 0x0FFFF;
         PPU.WRAM |= Byte << 16;
         PPU.WRAM &= 0x1FFFF;
         break;
      }
   }
   else
   {
      if (Settings.SA1)
      {
         if (Address >= 0x2200 && Address < 0x23ff)
            S9xSetSA1(Byte, Address);
         else
            Memory.FillRAM [Address] = Byte;

         return;
      }
      else
         // Dai Kaijyu Monogatari II
         if (Address == 0x2801 && Settings.SRTC)
            S9xSetSRTC(Byte, Address);
         else if (Address >= 0x3000 && Address < 0x3300)
         {
            S9xSetSuperFX(Byte, Address);
            return;

         }
   }
   Memory.FillRAM[Address] = Byte;

}

/******************************************************************************/
/* S9xGetPPU()                                                                */
/* This function retrieves a PPU Register                                     */
/******************************************************************************/
uint8_t S9xGetPPU(uint16_t Address)
{
   uint8_t byte;
   if (Address < 0x2100) //not a real PPU reg
      return OpenBus; //treat as unmapped memory returning last byte on the bus
   if (Address <= 0x2190)
   {
      switch (Address)
      {
      case 0x2100:
      case 0x2101:
      case 0x2102:
      case 0x2103:
         return OpenBus;

      case 0x2104:
      case 0x2105:
      case 0x2106:
      case 0x2108:
      case 0x2109:
      case 0x210a:
      case 0x2115:
      case 0x2116:
      case 0x2118:
      case 0x2119:
      case 0x211a:
      case 0x2124:
      case 0x2125:
      case 0x2126:
      case 0x2128:
      case 0x2129:
      case 0x212a:
         return PPU.OpenBus1;

      case 0x2107:
      case 0x2117:
      case 0x2121:
      case 0x2122:
      case 0x2123:
      case 0x2127:
      case 0x212b:
      case 0x212c:
      case 0x212d:
      case 0x212e:
      case 0x212f:
      case 0x2130:
      case 0x2131:
      case 0x2132:
      case 0x2133:
         return OpenBus;

      case 0x210b:
      case 0x210c:
      case 0x210d:
      case 0x210e:
      case 0x210f:
      case 0x2110:
      case 0x2111:
      case 0x2112:
      case 0x2113:
         return OpenBus;

      case 0x2114:
      case 0x211b:
      case 0x211c:
      case 0x211d:
      case 0x211e:
      case 0x211f:
      case 0x2120:
         return OpenBus;


      case 0x2134:
      case 0x2135:
      case 0x2136:
         // 16bit x 8bit multiply read result.
         if (PPU.Need16x8Mulitply)
         {
            int32_t r = (int32_t) PPU.MatrixA * (int32_t)(PPU.MatrixB >> 8);

            Memory.FillRAM[0x2134] = (uint8_t) r;
            Memory.FillRAM[0x2135] = (uint8_t)(r >> 8);
            Memory.FillRAM[0x2136] = (uint8_t)(r >> 16);
            PPU.Need16x8Mulitply = false;
         }
         return (PPU.OpenBus1 = Memory.FillRAM[Address]);
      case 0x2137:
         S9xLatchCounters(0);
         return OpenBus;

      case 0x2138:
         // Read OAM (sprite) control data
         if (PPU.OAMAddr & 0x100)
         {
            if (!(PPU.OAMFlip & 1))
               byte = PPU.OAMData [(PPU.OAMAddr & 0x10f) << 1];
            else
            {
               byte = PPU.OAMData [((PPU.OAMAddr & 0x10f) << 1) + 1];
               PPU.OAMAddr = (PPU.OAMAddr + 1) & 0x1ff;
               if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
               {
                  PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
                  IPPU.OBJChanged = true;
               }
            }
         }
         else
         {
            if (!(PPU.OAMFlip & 1))
               byte = PPU.OAMData [PPU.OAMAddr << 1];
            else
            {
               byte = PPU.OAMData [(PPU.OAMAddr << 1) + 1];
               ++PPU.OAMAddr;
               if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
               {
                  PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
                  IPPU.OBJChanged = true;
               }
            }
         }
         PPU.OAMFlip ^= 1;
         return (PPU.OpenBus1 = byte);

      case 0x2139:
         // Read vram low byte
#ifdef CORRECT_VRAM_READS
         byte = IPPU.VRAMReadBuffer & 0xff;
         if (!PPU.VMA.High)
         {
            if (PPU.VMA.FullGraphicCount)
            {
               uint32_t addr = PPU.VMA.Address;
               uint32_t rem = addr & PPU.VMA.Mask1;
               uint32_t address = (addr & ~PPU.VMA.Mask1) +
                                (rem >> PPU.VMA.Shift) +
                                ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
               IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((address << 1) & 0xFFFF));
            }
            else
               IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((PPU.VMA.Address << 1) &
                                               0xffff));
            PPU.VMA.Address += PPU.VMA.Increment;
         }
#else
         if (IPPU.FirstVRAMRead)
            byte = Memory.VRAM[(PPU.VMA.Address << 1) & 0xFFFF];
         else if (PPU.VMA.FullGraphicCount)
         {
            uint32_t addr = PPU.VMA.Address - 1;
            uint32_t rem = addr & PPU.VMA.Mask1;
            uint32_t address = (addr & ~PPU.VMA.Mask1) +
                             (rem >> PPU.VMA.Shift) +
                             ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
            byte = Memory.VRAM [((address << 1) - 2) & 0xFFFF];
         }
         else
            byte = Memory.VRAM[((PPU.VMA.Address << 1) - 2) & 0xffff];

         if (!PPU.VMA.High)
         {
            PPU.VMA.Address += PPU.VMA.Increment;
            IPPU.FirstVRAMRead = false;
         }
#endif
         PPU.OpenBus1 = byte;
         break;
      case 0x213A:
         // Read vram high byte
#ifdef CORRECT_VRAM_READS
         byte = (IPPU.VRAMReadBuffer >> 8) & 0xff;
         if (PPU.VMA.High)
         {
            if (PPU.VMA.FullGraphicCount)
            {
               uint32_t addr = PPU.VMA.Address;
               uint32_t rem = addr & PPU.VMA.Mask1;
               uint32_t address = (addr & ~PPU.VMA.Mask1) +
                                (rem >> PPU.VMA.Shift) +
                                ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
               IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((address << 1) & 0xFFFF));
            }
            else
               IPPU.VRAMReadBuffer = READ_WORD(Memory.VRAM + ((PPU.VMA.Address << 1) &
                                               0xffff));
            PPU.VMA.Address += PPU.VMA.Increment;
         }
#else
         if (IPPU.FirstVRAMRead)
            byte = Memory.VRAM[((PPU.VMA.Address << 1) + 1) & 0xffff];
         else if (PPU.VMA.FullGraphicCount)
         {
            uint32_t addr = PPU.VMA.Address - 1;
            uint32_t rem = addr & PPU.VMA.Mask1;
            uint32_t address = (addr & ~PPU.VMA.Mask1) +
                             (rem >> PPU.VMA.Shift) +
                             ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3);
            byte = Memory.VRAM [((address << 1) - 1) & 0xFFFF];
         }
         else
            byte = Memory.VRAM[((PPU.VMA.Address << 1) - 1) & 0xFFFF];
         if (PPU.VMA.High)
         {
            PPU.VMA.Address += PPU.VMA.Increment;
            IPPU.FirstVRAMRead = false;
         }
#endif
         PPU.OpenBus1 = byte;
         break;

      case 0x213B:
         // Read palette data
         if (PPU.CGFLIPRead)
            byte = PPU.CGDATA [PPU.CGADD++] >> 8;
         else
            byte = PPU.CGDATA [PPU.CGADD] & 0xff;

         PPU.CGFLIPRead ^= 1;
         return (PPU.OpenBus2 = byte);

      case 0x213C:
         // Horizontal counter value 0-339
         if (PPU.HBeamFlip)
            byte = (PPU.OpenBus2 & 0xfe)
                   | ((PPU.HBeamPosLatched >> 8) & 0x01);

         else
            byte = (uint8_t)PPU.HBeamPosLatched;
         PPU.OpenBus2 = byte;
         PPU.HBeamFlip ^= 1;
         break;

      case 0x213D:
         // Vertical counter value 0-262
         if (PPU.VBeamFlip)
            byte = (PPU.OpenBus2 & 0xfe)
                   | ((PPU.VBeamPosLatched >> 8) & 0x01);
         else
            byte = (uint8_t)PPU.VBeamPosLatched;
         PPU.OpenBus2 = byte;
         PPU.VBeamFlip ^= 1;
         break;

      case 0x213E:
         // PPU time and range over flags
         FLUSH_REDRAW();

         //so far, 5c77 version is always 1.
         return (PPU.OpenBus1 = (Model->_5C77 | PPU.RangeTimeOver));

      case 0x213F:
         // NTSC/PAL and which field flags
         PPU.VBeamFlip = PPU.HBeamFlip = 0;
         //neviksti found a 2 and a 3 here. SNEeSe uses a 3.
         //XXX: field flags not emulated
         return ((Settings.PAL ? 0x10 : 0) | (Memory.FillRAM[0x213f] & 0xc0) |
                 Model->_5C78) | (~PPU.OpenBus2 & 0x20);

      case 0x2140:
      case 0x2141:
      case 0x2142:
      case 0x2143:
      case 0x2144:
      case 0x2145:
      case 0x2146:
      case 0x2147:
      case 0x2148:
      case 0x2149:
      case 0x214a:
      case 0x214b:
      case 0x214c:
      case 0x214d:
      case 0x214e:
      case 0x214f:
      case 0x2150:
      case 0x2151:
      case 0x2152:
      case 0x2153:
      case 0x2154:
      case 0x2155:
      case 0x2156:
      case 0x2157:
      case 0x2158:
      case 0x2159:
      case 0x215a:
      case 0x215b:
      case 0x215c:
      case 0x215d:
      case 0x215e:
      case 0x215f:
      case 0x2160:
      case 0x2161:
      case 0x2162:
      case 0x2163:
      case 0x2164:
      case 0x2165:
      case 0x2166:
      case 0x2167:
      case 0x2168:
      case 0x2169:
      case 0x216a:
      case 0x216b:
      case 0x216c:
      case 0x216d:
      case 0x216e:
      case 0x216f:
      case 0x2170:
      case 0x2171:
      case 0x2172:
      case 0x2173:
      case 0x2174:
      case 0x2175:
      case 0x2176:
      case 0x2177:
      case 0x2178:
      case 0x2179:
      case 0x217a:
      case 0x217b:
      case 0x217c:
      case 0x217d:
      case 0x217e:
      case 0x217f:
#ifndef USE_BLARGG_APU
#ifdef SPCTOOL
         return ((uint8_t) _SPCOutP [Address & 3]);
#else
#ifdef SPC700_SHUTDOWN
         IAPU.APUExecuting = Settings.APUEnabled;
         IAPU.WaitCounter++;
#endif
         if (Settings.APUEnabled)
         {
            if (SNESGameFixes.APU_OutPorts_ReturnValueFix &&
                  Address >= 0x2140 && Address <= 0x2143 && !CPU.V_Counter)
            {
               return (uint8_t)((Address & 1) ? ((rand() & 0xff00) >> 8) :
                              (rand() & 0xff));
            }

            return (APU.OutPorts [Address & 3]);
         }
#endif
         switch (Settings.SoundSkipMethod)
         {
         case 0:
         case 1:
         case 3:
            CPU.BranchSkip = true;
            break;
         case 2:
            break;
         }
         if ((Address & 3) < 2)
         {
            int32_t r = rand();
            if (r & 2)
            {
               if (r & 4)
                  return ((Address & 3) == 1 ? 0xaa : 0xbb);
               else
                  return ((r >> 3) & 0xff);
            }
         }
         else
         {
            int32_t r = rand();
            if (r & 2)
               return ((r >> 3) & 0xff);
         }
         return (Memory.FillRAM[Address]);

#else // SPCTOOL
         return (S9xAPUReadPort(Address & 3));
#endif //#ifndef USE_BLARGG_APU

      case 0x2180:
         // Read WRAM
         byte = Memory.RAM [PPU.WRAM++];
         PPU.WRAM &= 0x1FFFF;
         break;
      case 0x2181:
      case 0x2182:
      case 0x2183:
      default:
         return OpenBus;
      }
   }
   else
   {
      if (Settings.SA1)
         return (S9xGetSA1(Address));

      if (Address <= 0x2fff || Address >= 0x3300)
      {
         switch (Address)
         {
         case 0x21c2:
            if (Model->_5C77 == 2)
               return (0x20);
            return OpenBus;
         case 0x21c3:
            if (Model->_5C77 == 2)
               return (0);
            return OpenBus;
         case 0x2800:
            // For Dai Kaijyu Monogatari II
            if (Settings.SRTC)
               return (S9xGetSRTC(Address));
         /*FALL*/

         default:
            return OpenBus;
         }
      }

      if (!Settings.SuperFX)
         return OpenBus;

      byte = Memory.FillRAM [Address];

#ifdef CPU_SHUTDOWN
      if (Address == 0x3030)
         CPU.WaitAddress = CPU.PCAtOpcodeStart;
      else
#endif
         if (Address == 0x3031)
         {
            CLEAR_IRQ_SOURCE(GSU_IRQ_SOURCE);
            Memory.FillRAM [0x3031] = byte & 0x7f;
         }
      return (byte);
   }
   return (byte);
}

/******************************************************************************/
/* S9xSetCPU()                                                                */
/* This function sets a CPU/DMA Register to a specific byte                   */
/******************************************************************************/
void S9xSetCPU(uint8_t byte, uint16_t Address)
{
   int32_t d;

   if (Address < 0x4200)
   {
      CPU.Cycles += ONE_CYCLE;
      switch (Address)
      {
      case 0x4016:
         // S9xReset reading of old-style joypads
         if ((byte & 1) && !(Memory.FillRAM [Address] & 1))
         {
            PPU.Joypad1ButtonReadPos = 0;
            PPU.Joypad2ButtonReadPos = 0;
            PPU.Joypad3ButtonReadPos = 0;
         }
         break;
      case 0x4017:
         return;
      default:
         break;
      }
   }
   else
      switch (Address)
      {
      case 0x4200:
         // NMI, V & H IRQ and joypad reading enable flags
         if (byte & 0x20)
         {
            if (!PPU.VTimerEnabled)
            {
               PPU.VTimerEnabled = true;
               if (PPU.HTimerEnabled)
                  S9xUpdateHTimer();
               else if (PPU.IRQVBeamPos == CPU.V_Counter)
                  S9xSetIRQ(PPU_V_BEAM_IRQ_SOURCE);
            }
         }
         else
         {
            PPU.VTimerEnabled = false;
         }

         if (byte & 0x10)
         {
            if (!PPU.HTimerEnabled)
            {
               PPU.HTimerEnabled = true;
               S9xUpdateHTimer();
            }
         }
         else
         {
            // No need to check for HTimer being disabled as the scanline
            // event trigger code won't trigger an H-IRQ unless its enabled.
            PPU.HTimerEnabled = false;
            PPU.HTimerPosition = Settings.H_Max + 1;
         }
         if (!Settings.DaffyDuck)
            CLEAR_IRQ_SOURCE(PPU_V_BEAM_IRQ_SOURCE | PPU_H_BEAM_IRQ_SOURCE);

         if ((byte & 0x80) &&
               !(Memory.FillRAM [0x4200] & 0x80) &&
               CPU.V_Counter >= PPU.ScreenHeight + FIRST_VISIBLE_LINE &&
               CPU.V_Counter <= PPU.ScreenHeight +
               (SNESGameFixes.alienVSpredetorFix ? 25 : 15)
               &&   //jyam 15->25 alien vs predetor
               // Panic Bomberman clears the NMI pending flag @ scanline 230 before enabling
               // NMIs again. The NMI routine crashes the CPU if it is called without the NMI
               // pending flag being set...
               (Memory.FillRAM [0x4210] & 0x80) &&
               !CPU.NMIActive)
         {
            CPU.Flags |= NMI_FLAG;
            CPU.NMIActive = true;
            CPU.NMICycleCount = CPU.NMITriggerPoint;
         }
         break;
      case 0x4201:
         if ((byte & 0x80) == 0 && (Memory.FillRAM[0x4213] & 0x80) == 0x80)
            S9xLatchCounters(1);
         Memory.FillRAM[0x4201] = Memory.FillRAM[0x4213] = byte;
         break;
      case 0x4202:
         // Multiplier (for multply)
         break;
      case 0x4203:
      {
         // Multiplicand
         uint32_t res = Memory.FillRAM[0x4202] * byte;

#if defined FAST_LSB_WORD_ACCESS || defined FAST_ALIGNED_LSB_WORD_ACCESS
         // assume malloc'd memory is 2-byte aligned
         * ((uint16_t*) &Memory.FillRAM[0x4216]) = res;
#else
         Memory.FillRAM[0x4216] = (uint8_t) res;
         Memory.FillRAM[0x4217] = (uint8_t)(res >> 8);
#endif
         break;
      }
      case 0x4204:
      case 0x4205:
         // Low and high muliplier (for divide)
         break;
      case 0x4206:
      {
#if defined FAST_LSB_WORD_ACCESS || defined FAST_ALIGNED_LSB_WORD_ACCESS
         // assume malloc'd memory is 2-byte aligned
         uint16_t a = *((uint16_t*) &Memory.FillRAM[0x4204]);
#else
         uint16_t a = Memory.FillRAM[0x4204] + (Memory.FillRAM[0x4205] << 8);
#endif
         uint16_t div = byte ? a / byte : 0xffff;
         uint16_t rem = byte ? a % byte : a;

#if defined FAST_LSB_WORD_ACCESS || defined FAST_ALIGNED_LSB_WORD_ACCESS
         // assume malloc'd memory is 2-byte aligned
         * ((uint16_t*) &Memory.FillRAM[0x4214]) = div;
         * ((uint16_t*) &Memory.FillRAM[0x4216]) = rem;
#else
         Memory.FillRAM[0x4214] = (uint8_t)div;
         Memory.FillRAM[0x4215] = div >> 8;
         Memory.FillRAM[0x4216] = (uint8_t)rem;
         Memory.FillRAM[0x4217] = rem >> 8;
#endif
         break;
      }
      case 0x4207:
         d = PPU.IRQHBeamPos;
         PPU.IRQHBeamPos = (PPU.IRQHBeamPos & 0xFF00) | byte;

         if (PPU.HTimerEnabled && PPU.IRQHBeamPos != d)
            S9xUpdateHTimer();
         break;

      case 0x4208:
         d = PPU.IRQHBeamPos;
         PPU.IRQHBeamPos = (PPU.IRQHBeamPos & 0xFF) | ((byte & 1) << 8);

         if (PPU.HTimerEnabled && PPU.IRQHBeamPos != d)
            S9xUpdateHTimer();

         break;

      case 0x4209:
         d = PPU.IRQVBeamPos;
         PPU.IRQVBeamPos = (PPU.IRQVBeamPos & 0xFF00) | byte;
         if (PPU.VTimerEnabled && PPU.IRQVBeamPos != d)
         {
            if (PPU.HTimerEnabled)
               S9xUpdateHTimer();
            else
            {
               if (PPU.IRQVBeamPos == CPU.V_Counter)
                  S9xSetIRQ(PPU_V_BEAM_IRQ_SOURCE);
            }
         }
         break;

      case 0x420A:
         d = PPU.IRQVBeamPos;
         PPU.IRQVBeamPos = (PPU.IRQVBeamPos & 0xFF) | ((byte & 1) << 8);
         if (PPU.VTimerEnabled && PPU.IRQVBeamPos != d)
         {
            if (PPU.HTimerEnabled)
               S9xUpdateHTimer();
            else
            {
               if (PPU.IRQVBeamPos == CPU.V_Counter)
                  S9xSetIRQ(PPU_V_BEAM_IRQ_SOURCE);
            }
         }
         break;

      case 0x420B:
         if ((byte & 0x01) != 0)
            S9xDoDMA(0);
         if ((byte & 0x02) != 0)
            S9xDoDMA(1);
         if ((byte & 0x04) != 0)
            S9xDoDMA(2);
         if ((byte & 0x08) != 0)
            S9xDoDMA(3);
         if ((byte & 0x10) != 0)
            S9xDoDMA(4);
         if ((byte & 0x20) != 0)
            S9xDoDMA(5);
         if ((byte & 0x40) != 0)
            S9xDoDMA(6);
         if ((byte & 0x80) != 0)
            S9xDoDMA(7);
         break;
      case 0x420C:
         if (Settings.DisableHDMA)
            byte = 0;
         Memory.FillRAM[0x420c] = byte;
         IPPU.HDMA = byte;
         break;

      case 0x420d:
         // Cycle speed 0 - 2.68Mhz, 1 - 3.58Mhz (banks 0x80 +)
         if ((byte & 1) != (Memory.FillRAM [0x420d] & 1))
         {
            if (byte & 1)
               CPU.FastROMSpeed = ONE_CYCLE;
            else CPU.FastROMSpeed = SLOW_ONE_CYCLE;

            FixROMSpeed();
         }
         break;

      case 0x420e:
      case 0x420f:
         // --->>> Unknown
         break;
      case 0x4210:
         // NMI ocurred flag (reset on read or write)
         Memory.FillRAM[0x4210] = Model->_5A22;
         return;
      case 0x4211:
         // IRQ ocurred flag (reset on read or write)
         CLEAR_IRQ_SOURCE(PPU_V_BEAM_IRQ_SOURCE | PPU_H_BEAM_IRQ_SOURCE);
         break;
      case 0x4212:
      // v-blank, h-blank and joypad being scanned flags (read-only)
      /* fall through */
      case 0x4213:
      // I/O Port (read-only)
      /* fall through */
      case 0x4214:
      case 0x4215:
      // Quotent of divide (read-only)
      /* fall through */
      case 0x4216:
      case 0x4217:
      // Multiply product (read-only)
      /* fall through */
      case 0x4218:
      case 0x4219:
      case 0x421a:
      case 0x421b:
      case 0x421c:
      case 0x421d:
      case 0x421e:
      case 0x421f:
         // Joypad values (read-only)
         return;

      case 0x4300:
      case 0x4310:
      case 0x4320:
      case 0x4330:
      case 0x4340:
      case 0x4350:
      case 0x4360:
      case 0x4370:
         d = (Address >> 4) & 0x7;
         DMA[d].TransferDirection = (byte & 128) != 0 ? 1 : 0;
         DMA[d].HDMAIndirectAddressing = (byte & 64) != 0 ? 1 : 0;
         DMA[d].AAddressDecrement = (byte & 16) != 0 ? 1 : 0;
         DMA[d].AAddressFixed = (byte & 8) != 0 ? 1 : 0;
         DMA[d].TransferMode = (byte & 7);
         break;

      case 0x4301:
      case 0x4311:
      case 0x4321:
      case 0x4331:
      case 0x4341:
      case 0x4351:
      case 0x4361:
      case 0x4371:
         DMA[((Address >> 4) & 0x7)].BAddress = byte;
         break;

      case 0x4302:
      case 0x4312:
      case 0x4322:
      case 0x4332:
      case 0x4342:
      case 0x4352:
      case 0x4362:
      case 0x4372:
         d = (Address >> 4) & 0x7;
         DMA[d].AAddress &= 0xFF00;
         DMA[d].AAddress |= byte;
         break;

      case 0x4303:
      case 0x4313:
      case 0x4323:
      case 0x4333:
      case 0x4343:
      case 0x4353:
      case 0x4363:
      case 0x4373:
         d = (Address >> 4) & 0x7;
         DMA[d].AAddress &= 0xFF;
         DMA[d].AAddress |= byte << 8;
         break;

      case 0x4304:
      case 0x4314:
      case 0x4324:
      case 0x4334:
      case 0x4344:
      case 0x4354:
      case 0x4364:
      case 0x4374:
         DMA[((Address >> 4) & 0x7)].ABank = byte;
         HDMAMemPointers[((Address >> 4) & 0x7)] = NULL;

         break;

      case 0x4305:
      case 0x4315:
      case 0x4325:
      case 0x4335:
      case 0x4345:
      case 0x4355:
      case 0x4365:
      case 0x4375:
         d = (Address >> 4) & 0x7;
         DMA[d].TransferBytes &= 0xFF00;
         DMA[d].TransferBytes |= byte;
         DMA[d].IndirectAddress &= 0xff00;
         DMA[d].IndirectAddress |= byte;
         HDMAMemPointers[d] = NULL;
         break;

      case 0x4306:
      case 0x4316:
      case 0x4326:
      case 0x4336:
      case 0x4346:
      case 0x4356:
      case 0x4366:
      case 0x4376:
         d = (Address >> 4) & 0x7;
         DMA[d].TransferBytes &= 0xFF;
         DMA[d].TransferBytes |= byte << 8;
         DMA[d].IndirectAddress &= 0xff;
         DMA[d].IndirectAddress |= byte << 8;
         HDMAMemPointers[d] = NULL;
         break;

      case 0x4307:
      case 0x4317:
      case 0x4327:
      case 0x4337:
      case 0x4347:
      case 0x4357:
      case 0x4367:
      case 0x4377:
         DMA[d = ((Address >> 4) & 0x7)].IndirectBank = byte;
         HDMAMemPointers[d] = NULL;
         break;

      case 0x4308:
      case 0x4318:
      case 0x4328:
      case 0x4338:
      case 0x4348:
      case 0x4358:
      case 0x4368:
      case 0x4378:
         d = (Address >> 4) & 7;
         DMA[d].Address &= 0xff00;
         DMA[d].Address |= byte;
         HDMAMemPointers[d] = NULL;
         break;

      case 0x4309:
      case 0x4319:
      case 0x4329:
      case 0x4339:
      case 0x4349:
      case 0x4359:
      case 0x4369:
      case 0x4379:
         d = (Address >> 4) & 0x7;
         DMA[d].Address &= 0xff;
         DMA[d].Address |= byte << 8;
         HDMAMemPointers[d] = NULL;
         break;

      case 0x430A:
      case 0x431A:
      case 0x432A:
      case 0x433A:
      case 0x434A:
      case 0x435A:
      case 0x436A:
      case 0x437A:
         d = (Address >> 4) & 0x7;
         DMA[d].LineCount = byte & 0x7f;
         DMA[d].Repeat = !(byte & 0x80);
         break;

      case 0x430F:
      case 0x431F:
      case 0x432F:
      case 0x433F:
      case 0x434F:
      case 0x435F:
      case 0x436F:
      case 0x437F:
         Address &= ~4; // Convert 43xF to 43xB
      /* fall through */
      case 0x430B:
      case 0x431B:
      case 0x432B:
      case 0x433B:
      case 0x434B:
      case 0x435B:
      case 0x436B:
      case 0x437B:
         // Unknown, but they seem to be RAM-ish
         break;

      //These registers are used by both the S-DD1 and the SPC7110
      case 0x4800:
      case 0x4801:
      case 0x4802:
      case 0x4803:
         if (Settings.SPC7110)
            S9xSetSPC7110(byte, Address);
         break;

      case 0x4804:
      case 0x4805:
      case 0x4806:
      case 0x4807:
         if (Settings.SPC7110)
            S9xSetSPC7110(byte, Address);
         else S9xSetSDD1MemoryMap(Address - 0x4804, byte & 7);
         break;

      //these are used by the SPC7110
      case 0x4808:
      case 0x4809:
      case 0x480A:
      case 0x480B:
      case 0x480C:
      case 0x4810:
      case 0x4811:
      case 0x4812:
      case 0x4813:
      case 0x4814:
      case 0x4815:
      case 0x4816:
      case 0x4817:
      case 0x4818:
      case 0x481A:
      case 0x4820:
      case 0x4821:
      case 0x4822:
      case 0x4823:
      case 0x4824:
      case 0x4825:
      case 0x4826:
      case 0x4827:
      case 0x4828:
      case 0x4829:
      case 0x482A:
      case 0x482B:
      case 0x482C:
      case 0x482D:
      case 0x482E:
      case 0x482F:
      case 0x4830:
      case 0x4831:
      case 0x4832:
      case 0x4833:
      case 0x4834:
      case 0x4840:
      case 0x4841:
      case 0x4842:
         if (Settings.SPC7110)
         {
            S9xSetSPC7110(byte, Address);
            break;
         }

      default:
         break;
      }
   Memory.FillRAM [Address] = byte;
}

/******************************************************************************/
/* S9xGetCPU()                                                                */
/* This function retrieves a CPU/DMA Register                                 */
/******************************************************************************/
uint8_t S9xGetCPU(uint16_t Address)
{
   uint8_t byte;

   if (Address < 0x4200)
   {
      CPU.Cycles += ONE_CYCLE;
      switch (Address)
      {
      case 0x4016:
      {
         if (Memory.FillRAM [0x4016] & 1)
            return 0;

         if (PPU.Joypad1ButtonReadPos >= 16) // Joypad 1 is enabled
            return 1;

         return (IPPU.Joypads[0] >> (PPU.Joypad1ButtonReadPos++ ^ 15)) & 1;
      }
      case 0x4017:
      {
         if (Memory.FillRAM [0x4016] & 1)
         {
            // MultiPlayer5 adaptor is only allowed to be plugged into port 2
            switch (IPPU.Controller)
            {
            case SNES_MULTIPLAYER5:
               return (2);
            case SNES_MOUSE:
               break;
            }

            return 0;
         }

         if (IPPU.Controller == SNES_MULTIPLAYER5)
         {
            if (Memory.FillRAM [0x4201] & 0x80)
            {
               byte = ((IPPU.Joypads[1] >> (PPU.Joypad2ButtonReadPos ^ 15)) & 1) |
                      (((IPPU.Joypads[2] >> (PPU.Joypad2ButtonReadPos ^ 15)) & 1) << 1);
               PPU.Joypad2ButtonReadPos++;
               return (byte);
            }
            else
            {
               byte = ((IPPU.Joypads[3] >> (PPU.Joypad3ButtonReadPos ^ 15)) & 1) |
                      (((IPPU.Joypads[4] >> (PPU.Joypad3ButtonReadPos ^ 15)) & 1) << 1);
               PPU.Joypad3ButtonReadPos++;
               return (byte);
            }
         }
         else if (IPPU.Controller == SNES_JUSTIFIER || IPPU.Controller == SNES_JUSTIFIER_2)
         {
            uint8_t rv;
            rv = (1 & (justifiers >> in_bit));
            in_bit++;
            in_bit %= 32;
            return rv;
         }

         if (PPU.Joypad2ButtonReadPos >= 16) // Joypad 2 is enabled
            return 1;

         return (IPPU.Joypads[1] >> (PPU.Joypad2ButtonReadPos++ ^ 15)) & 1;
      }
      default:
         return OpenBus;
      }
   }
   else
      switch (Address)
      {
      case 0x4200:
      case 0x4201:
      case 0x4202:
      case 0x4203:
      case 0x4204:
      case 0x4205:
      case 0x4206:
      case 0x4207:
      case 0x4208:
      case 0x4209:
      case 0x420a:
      case 0x420b:
      case 0x420c:
      case 0x420d:
      case 0x420e:
      case 0x420f:
         return OpenBus;

      case 0x4210:
#ifdef CPU_SHUTDOWN
         CPU.WaitAddress = CPU.PCAtOpcodeStart;
#endif
         byte = Memory.FillRAM[0x4210];
         Memory.FillRAM[0x4210] = Model->_5A22;
         //SNEeSe returns 2 for 5A22 version.
         return ((byte & 0x80)
                 | (OpenBus & 0x70)
                 | Model->_5A22);

      case 0x4211:
         byte = (CPU.IRQActive & (PPU_V_BEAM_IRQ_SOURCE | PPU_H_BEAM_IRQ_SOURCE)) ?
                0x80 : 0;
         // Super Robot Wars Ex ROM bug requires this.
         byte |= CPU.Cycles >= Settings.HBlankStart ? 0x40 : 0;
         CLEAR_IRQ_SOURCE(PPU_V_BEAM_IRQ_SOURCE | PPU_H_BEAM_IRQ_SOURCE);

         // Maybe? Register Scan indicated open bus...
         byte |= OpenBus & 0x3f;

         return (byte);

      case 0x4212:
         // V-blank, h-blank and joypads being read flags (read-only)
#ifdef CPU_SHUTDOWN
         CPU.WaitAddress = CPU.PCAtOpcodeStart;
#endif
         return (REGISTER_4212()
                 | (OpenBus & 0x3E)
                );

      case 0x4213:
      // I/O port input - returns 0 wherever $4201 is 0, and 1 elsewhere
      // unless something else pulls it down (i.e. a gun)
      /* fall through */
      case 0x4214:
      case 0x4215:
      // Quotient of divide result
      case 0x4216:
      case 0x4217:
      // Multiplcation result (for multiply) or remainder of
      // divison.
      /* fall through */
      case 0x4218:
      case 0x4219:
      case 0x421a:
      case 0x421b:
      case 0x421c:
      case 0x421d:
      case 0x421e:
      case 0x421f:
      // Joypads 1-4 button and direction state.
      /* fall through */
      case 0x4300:
      case 0x4310:
      case 0x4320:
      case 0x4330:
      case 0x4340:
      case 0x4350:
      case 0x4360:
      case 0x4370:
      // DMA direction, address type, fixed flag,
      /* fall through */
      case 0x4301:
      case 0x4311:
      case 0x4321:
      case 0x4331:
      case 0x4341:
      case 0x4351:
      case 0x4361:
      case 0x4371:
      /* fall through */
      case 0x4302:
      case 0x4312:
      case 0x4322:
      case 0x4332:
      case 0x4342:
      case 0x4352:
      case 0x4362:
      case 0x4372:
      /* fall through */
      case 0x4303:
      case 0x4313:
      case 0x4323:
      case 0x4333:
      case 0x4343:
      case 0x4353:
      case 0x4363:
      case 0x4373:
      /* fall through */
      case 0x4304:
      case 0x4314:
      case 0x4324:
      case 0x4334:
      case 0x4344:
      case 0x4354:
      case 0x4364:
      case 0x4374:
      /* fall through */
      case 0x4305:
      case 0x4315:
      case 0x4325:
      case 0x4335:
      case 0x4345:
      case 0x4355:
      case 0x4365:
      case 0x4375:
      /* fall through */
      case 0x4306:
      case 0x4316:
      case 0x4326:
      case 0x4336:
      case 0x4346:
      case 0x4356:
      case 0x4366:
      case 0x4376:
      /* fall through */
      case 0x4308:
      case 0x4318:
      case 0x4328:
      case 0x4338:
      case 0x4348:
      case 0x4358:
      case 0x4368:
      case 0x4378:
      /* fall through */
      case 0x4309:
      case 0x4319:
      case 0x4329:
      case 0x4339:
      case 0x4349:
      case 0x4359:
      case 0x4369:
      case 0x4379:
         return (Memory.FillRAM[Address]);

      case 0x4307:
      case 0x4317:
      case 0x4327:
      case 0x4337:
      case 0x4347:
      case 0x4357:
      case 0x4367:
      case 0x4377:
         return (DMA[(Address >> 4) & 7].IndirectBank);

      case 0x430A:
      case 0x431A:
      case 0x432A:
      case 0x433A:
      case 0x434A:
      case 0x435A:
      case 0x436A:
      case 0x437A:
      {
         int32_t d = (Address & 0x70) >> 4;
         if (IPPU.HDMA & (1 << d))
            return (DMA[d].LineCount);
         return (Memory.FillRAM[Address]);
      }

      case 0x430F:
      case 0x431F:
      case 0x432F:
      case 0x433F:
      case 0x434F:
      case 0x435F:
      case 0x436F:
      case 0x437F:
         Address &= ~4; // Convert 43xF to 43xB
      /* fall through */
      case 0x430B:
      case 0x431B:
      case 0x432B:
      case 0x433B:
      case 0x434B:
      case 0x435B:
      case 0x436B:
      case 0x437B:
         // Unknown, but they seem to be RAM-ish
         return (Memory.FillRAM[Address]);

      default:
         if (Address >= 0x4800 && Settings.SPC7110)
            return S9xGetSPC7110(Address);

         if (Address >= 0x4800 && Address <= 0x4807 && Settings.SDD1)
            return Memory.FillRAM[Address];

         return OpenBus;
      }
}

static void CommonPPUReset()
{
   PPU.BGMode = 0;
   PPU.BG3Priority = 0;
   PPU.Brightness = 0;
   PPU.VMA.High = 0;
   PPU.VMA.Increment = 1;
   PPU.VMA.Address = 0;
   PPU.VMA.FullGraphicCount = 0;
   PPU.VMA.Shift = 0;

   uint8_t B;
   for (B = 0; B != 4; B++)
   {
      PPU.BG[B].SCBase = 0;
      PPU.BG[B].VOffset = 0;
      PPU.BG[B].HOffset = 0;
      PPU.BG[B].BGSize = 0;
      PPU.BG[B].NameBase = 0;
      PPU.BG[B].SCSize = 0;

      PPU.ClipCounts[B] = 0;
      PPU.ClipWindowOverlapLogic [B] = CLIP_OR;
      PPU.ClipWindow1Enable[B] = false;
      PPU.ClipWindow2Enable[B] = false;
      PPU.ClipWindow1Inside[B] = true;
      PPU.ClipWindow2Inside[B] = true;
   }

   PPU.ClipCounts[4] = 0;
   PPU.ClipCounts[5] = 0;
   PPU.ClipWindowOverlapLogic[4] = PPU.ClipWindowOverlapLogic[5] = CLIP_OR;
   PPU.ClipWindow1Enable[4] = PPU.ClipWindow1Enable[5] = false;
   PPU.ClipWindow2Enable[4] = PPU.ClipWindow2Enable[5] = false;
   PPU.ClipWindow1Inside[4] = PPU.ClipWindow1Inside[5] = true;
   PPU.ClipWindow2Inside[4] = PPU.ClipWindow2Inside[5] = true;

   PPU.CGFLIP = 0;
   int32_t c;
   for (c = 0; c < 256; c++)
   {
      IPPU.Red [c] = (c & 7) << 2;
      IPPU.Green [c] = ((c >> 3) & 7) << 2;
      IPPU.Blue [c] = ((c >> 6) & 2) << 3;
      PPU.CGDATA [c] = IPPU.Red [c] | (IPPU.Green [c] << 5) |
                       (IPPU.Blue [c] << 10);
   }

   PPU.FirstSprite = 0;
   PPU.LastSprite = 127;
   int32_t Sprite;
   for (Sprite = 0; Sprite < 128; Sprite++)
   {
      PPU.OBJ[Sprite].HPos = 0;
      PPU.OBJ[Sprite].VPos = 0;
      PPU.OBJ[Sprite].VFlip = 0;
      PPU.OBJ[Sprite].HFlip = 0;
      PPU.OBJ[Sprite].Priority = 0;
      PPU.OBJ[Sprite].Palette = 0;
      PPU.OBJ[Sprite].Name = 0;
      PPU.OBJ[Sprite].Size = 0;
   }
   PPU.OAMPriorityRotation = 0;
   PPU.OAMWriteRegister = 0;
   PPU.RangeTimeOver = 0;
   PPU.OpenBus1 = 0;
   PPU.OpenBus2 = 0;

   PPU.OAMFlip = 0;
   PPU.OAMTileAddress = 0;
   PPU.OAMAddr = 0;
   PPU.IRQVBeamPos = 0;
   PPU.IRQHBeamPos = 0;
   PPU.VBeamPosLatched = 0;
   PPU.HBeamPosLatched = 0;

   PPU.HBeamFlip = 0;
   PPU.VBeamFlip = 0;
   PPU.HVBeamCounterLatched = 0;

   PPU.MatrixA = PPU.MatrixB = PPU.MatrixC = PPU.MatrixD = 0;
   PPU.CentreX = PPU.CentreY = 0;
   PPU.CGADD = 0;
   PPU.FixedColourRed = PPU.FixedColourGreen = PPU.FixedColourBlue = 0;
   PPU.SavedOAMAddr = 0;
   PPU.ScreenHeight = SNES_HEIGHT;
   PPU.WRAM = 0;
   PPU.BG_Forced = 0;
   PPU.ForcedBlanking = true;
   PPU.OBJThroughMain = false;
   PPU.OBJThroughSub = false;
   PPU.OBJSizeSelect = 0;
   PPU.OBJNameSelect = 0;
   PPU.OBJNameBase = 0;
   PPU.OBJAddition = false;
   PPU.OAMReadFlip = 0;
   PPU.BGnxOFSbyte = 0;
   memset(PPU.OAMData, 0, 512 + 32);

   PPU.VTimerEnabled = false;
   PPU.HTimerEnabled = false;
   PPU.HTimerPosition = Settings.H_Max + 1;
   PPU.Mosaic = 0;
   PPU.BGMosaic [0] = PPU.BGMosaic [1] = false;
   PPU.BGMosaic [2] = PPU.BGMosaic [3] = false;
   PPU.Mode7HFlip = false;
   PPU.Mode7VFlip = false;
   PPU.Mode7Repeat = 0;
   PPU.Window1Left = 1;
   PPU.Window1Right = 0;
   PPU.Window2Left = 1;
   PPU.Window2Right = 0;
   PPU.RecomputeClipWindows = true;
   PPU.CGFLIPRead = 0;
   PPU.Need16x8Mulitply = false;
   PPU.MouseSpeed[0] = PPU.MouseSpeed[1] = 0;

   IPPU.ColorsChanged = true;
   IPPU.HDMA = 0;
   IPPU.HDMAStarted = false;
   IPPU.MaxBrightness = 0;
   IPPU.LatchedBlanking = 0;
   IPPU.OBJChanged = true;
   IPPU.RenderThisFrame = true;
   IPPU.DirectColourMapsNeedRebuild = true;
   IPPU.FrameCount = 0;
   IPPU.RenderedFramesCount = 0;
   IPPU.DisplayedRenderedFrameCount = 0;
   IPPU.SkippedFrames = 0;
   IPPU.FrameSkip = 0;
   memset(IPPU.TileCached [TILE_2BIT], 0, MAX_2BIT_TILES);
   memset(IPPU.TileCached [TILE_4BIT], 0, MAX_4BIT_TILES);
   memset(IPPU.TileCached [TILE_8BIT], 0, MAX_8BIT_TILES);
#ifdef CORRECT_VRAM_READS
   IPPU.VRAMReadBuffer = 0; // XXX: FIXME: anything better?
#else
   IPPU.FirstVRAMRead = false;
#endif
   IPPU.Interlace = false;
   IPPU.InterlaceSprites = false;
   IPPU.DoubleWidthPixels = false;
   IPPU.HalfWidthPixels = false;
   IPPU.DoubleHeightPixels = false;
   IPPU.RenderedScreenWidth = SNES_WIDTH;
   IPPU.RenderedScreenHeight = SNES_HEIGHT;
   IPPU.XB = NULL;
   for (c = 0; c < 256; c++)
      IPPU.ScreenColors [c] = c;
   S9xFixColourBrightness();
   IPPU.PreviousLine = IPPU.CurrentLine = 0;

   if (Settings.ControllerOption == 0)
      IPPU.Controller = SNES_MAX_CONTROLLER_OPTIONS - 1;
   else
      IPPU.Controller = Settings.ControllerOption - 1;
   S9xNextController();

   for (c = 0; c < 2; c++)
      memset(&IPPU.Clip [c], 0, sizeof(struct ClipData));

   if (Settings.MouseMaster)
   {
      S9xProcessMouse(0);
      S9xProcessMouse(1);
   }
}

void S9xResetPPU()
{
   CommonPPUReset();
   PPU.Joypad1ButtonReadPos = 0;
   PPU.Joypad2ButtonReadPos = 0;
   PPU.Joypad3ButtonReadPos = 0;

   IPPU.Joypads[0] = IPPU.Joypads[1] = IPPU.Joypads[2] = 0;
   IPPU.Joypads[3] = IPPU.Joypads[4] = 0;
   IPPU.SuperScope = 0;
   IPPU.Mouse[0] = IPPU.Mouse[1] = 0;
   IPPU.PrevMouseX[0] = IPPU.PrevMouseX[1] = 256 / 2;
   IPPU.PrevMouseY[0] = IPPU.PrevMouseY[1] = 224 / 2;

   int32_t c;
   for (c = 0; c < 0x8000; c += 0x100)
   {
      if (!Settings.SuperFX)
         memset(&Memory.FillRAM [c], c >> 8, 0x100);
      else if ((uint32_t)c < 0x3000 || (uint32_t)c >= 0x3300)
      {
         /* Don't overwrite SFX pvRegisters at 0x3000-0x32FF,
          * they were set in FxReset.
          */
         memset(&Memory.FillRAM [c], c >> 8, 0x100);
      }
   }

   memset(&Memory.FillRAM [0x2100], 0, 0x100);
   memset(&Memory.FillRAM [0x4200], 0, 0x100);
   memset(&Memory.FillRAM [0x4000], 0, 0x100);
   // For BS Suttehakkun 2...
   memset(&Memory.FillRAM [0x1000], 0, 0x1000);

   Memory.FillRAM[0x4201] = Memory.FillRAM[0x4213] = 0xFF;
}

void S9xSoftResetPPU()
{
   CommonPPUReset();

   int32_t c;
   for (c = 0; c < 0x8000; c += 0x100)
      memset(&Memory.FillRAM [c], c >> 8, 0x100);

   memset(&Memory.FillRAM [0x2100], 0, 0x100);
   memset(&Memory.FillRAM [0x4200], 0, 0x100);
   memset(&Memory.FillRAM [0x4000], 0, 0x100);
   // For BS Suttehakkun 2...
   memset(&Memory.FillRAM [0x1000], 0, 0x1000);

   Memory.FillRAM[0x4201] = Memory.FillRAM[0x4213] = 0xFF;
}

void S9xProcessMouse(int32_t which1)
{
   int32_t x, y;
   uint32_t buttons;

   if (IPPU.Controller == SNES_MOUSE && S9xReadMousePosition(which1, &x, &y, &buttons))
   {
      int32_t delta_x, delta_y;
#define MOUSE_SIGNATURE 0x1
      IPPU.Mouse [which1] = MOUSE_SIGNATURE |
                            (PPU.MouseSpeed [which1] << 4) |
                            ((buttons & 1) << 6) | ((buttons & 2) << 6);

      delta_x = x - IPPU.PrevMouseX[which1];
      delta_y = y - IPPU.PrevMouseY[which1];

      if (delta_x > 63)
      {
         delta_x = 63;
         IPPU.PrevMouseX[which1] += 63;
      }
      else if (delta_x < -63)
      {
         delta_x = -63;
         IPPU.PrevMouseX[which1] -= 63;
      }
      else
         IPPU.PrevMouseX[which1] = x;

      if (delta_y > 63)
      {
         delta_y = 63;
         IPPU.PrevMouseY[which1] += 63;
      }
      else if (delta_y < -63)
      {
         delta_y = -63;
         IPPU.PrevMouseY[which1] -= 63;
      }
      else
         IPPU.PrevMouseY[which1] = y;

      if (delta_x < 0)
      {
         delta_x = -delta_x;
         IPPU.Mouse [which1] |= (delta_x | 0x80) << 16;
      }
      else
         IPPU.Mouse [which1] |= delta_x << 16;

      if (delta_y < 0)
      {
         delta_y = -delta_y;
         IPPU.Mouse [which1] |= (delta_y | 0x80) << 24;
      }
      else
         IPPU.Mouse [which1] |= delta_y << 24;

      IPPU.Joypads [1] = IPPU.Mouse [which1];
   }
}

void ProcessSuperScope()
{
   int32_t x, y;
   uint32_t buttons;

   if (IPPU.Controller == SNES_SUPERSCOPE &&
         S9xReadSuperScopePosition(&x, &y, &buttons))
   {
#define SUPERSCOPE_SIGNATURE 0x00ff
      uint32_t scope;

      scope = SUPERSCOPE_SIGNATURE | ((buttons & 1) << (7 + 8)) |
              ((buttons & 2) << (5 + 8)) | ((buttons & 4) << (3 + 8)) |
              ((buttons & 8) << (1 + 8));
      if (Memory.FillRAM[0x4201] & 0x80)
      {
         x += 40;
         if (x > 295)
            x = 295;
         if (x < 40)
            x = 40;
         if (y > PPU.ScreenHeight - 1)
            y = PPU.ScreenHeight - 1;
         if (y < 0)
            y = 0;

         PPU.VBeamPosLatched = (uint16_t)(y + 1);
         PPU.HBeamPosLatched = (uint16_t) x;
         PPU.HVBeamCounterLatched = true;
         Memory.FillRAM [0x213F] |= 0x40 | Model->_5C78;
      }
      IPPU.Joypads [1] = scope;
   }
}

void S9xNextController()
{
   switch (IPPU.Controller)
   {
   case SNES_MULTIPLAYER5:
      IPPU.Controller = SNES_JOYPAD;
      break;
   case SNES_JOYPAD:
      if (Settings.MouseMaster)
      {
         IPPU.Controller = SNES_MOUSE;
         break;
      }
   case SNES_MOUSE:
      if (Settings.SuperScopeMaster)
      {
         IPPU.Controller = SNES_SUPERSCOPE;
         break;
      }
   case SNES_SUPERSCOPE:
      if (Settings.JustifierMaster)
      {
         IPPU.Controller = SNES_JUSTIFIER;
         break;
      }
   case SNES_JUSTIFIER:
      if (Settings.JustifierMaster)
      {
         IPPU.Controller = SNES_JUSTIFIER_2;
         break;
      }
   case SNES_JUSTIFIER_2:
      if (Settings.MultiPlayer5Master)
      {
         IPPU.Controller = SNES_MULTIPLAYER5;
         break;
      }
   default:
      IPPU.Controller = SNES_JOYPAD;
      break;
   }
}

void S9xUpdateJustifiers()
{
   static bool last_p1;
   in_bit = 0;
   justifiers = 0xFFFF00AA;

   bool offscreen = JustifierOffscreen();

   JustifierButtons(&justifiers);
   last_p1 = !last_p1;

   if (!last_p1)
      justifiers |= 0x1000;

   int32_t x, y;
   uint32_t buttons;

   if (Memory.FillRAM[0x4201] & 0x80)
   {

      S9xReadSuperScopePosition(&x, &y, &buttons);

      x += 40;
      if (x > 295)
         x = 295;
      if (x < 40)
         x = 40;
      if (y > PPU.ScreenHeight - 1)
         y = PPU.ScreenHeight - 1;
      if (y < 0)
         y = 0;

      if (last_p1)
      {

         PPU.HVBeamCounterLatched = false;
         Memory.FillRAM [0x213F] = Model->_5C78;

         //process latch as Justifier 2
         if (Settings.SecondJustifier)
         {
            if (IPPU.Controller == SNES_JUSTIFIER_2)
            {
               if (!offscreen)
               {

                  PPU.VBeamPosLatched = (uint16_t)(y + 1);
                  PPU.HBeamPosLatched = (uint16_t) x;
                  PPU.HVBeamCounterLatched = true;
                  Memory.FillRAM [0x213F] |= 0x40 | Model->_5C78;
               }
            }
         }
      }
      else
      {

         PPU.HVBeamCounterLatched = false;
         Memory.FillRAM [0x213F] = Model->_5C78;

         //emulate player 1.
         if (IPPU.Controller == SNES_JUSTIFIER)
         {
            if (!offscreen)
            {
               PPU.VBeamPosLatched = (uint16_t)(y + 1);
               PPU.HBeamPosLatched = (uint16_t) x;
               PPU.HVBeamCounterLatched = true;
               Memory.FillRAM [0x213F] |= 0x40 | Model->_5C78;
            }
         }
      }

      //needs restructure
      if (!offscreen)
      {

         if ((!last_p1 && IPPU.Controller == SNES_JUSTIFIER) || (last_p1
               && IPPU.Controller == SNES_JUSTIFIER_2))
         {
            PPU.VBeamPosLatched = (uint16_t)(y + 1);
            PPU.HBeamPosLatched = (uint16_t) x;
            PPU.HVBeamCounterLatched = true;
            Memory.FillRAM [0x213F] |= 0x40 | Model->_5C78;
         }
         else
         {
            PPU.HVBeamCounterLatched = false;
            Memory.FillRAM [0x213F] = Model->_5C78;

         }
      }
      else
      {
         PPU.HVBeamCounterLatched = false;
         Memory.FillRAM [0x213F] = Model->_5C78;
      }
   }
}

void S9xUpdateJoypads()
{
   uint32_t i;

   for (i = 0; i < 5; i++)
      IPPU.Joypads [i] = S9xReadJoypad(i);

   for (i = 0; i < 5; i++)
   {
      if ((IPPU.Joypads [i] & (SNES_LEFT_MASK | SNES_RIGHT_MASK)) ==
            (SNES_LEFT_MASK | SNES_RIGHT_MASK))
         IPPU.Joypads [i] &= ~SNES_RIGHT_MASK;
      if ((IPPU.Joypads [i] & (SNES_UP_MASK | SNES_DOWN_MASK)) ==
            (SNES_UP_MASK | SNES_DOWN_MASK))
         IPPU.Joypads [i] &= ~SNES_DOWN_MASK;
   }

   // BJ: This is correct behavior AFAICT (used to be Touhaiden hack)
   if (IPPU.Controller == SNES_JOYPAD || IPPU.Controller == SNES_MULTIPLAYER5)
   {
      for (i = 0; i < 5; i++)
      {
         if (IPPU.Joypads [i])
            IPPU.Joypads [i] |= 0xffff0000;
      }
   }

   // Read mouse position if enabled
   if (Settings.MouseMaster)
   {
      for (i = 0; i < 2; i++)
         S9xProcessMouse(i);
   }

   // Read SuperScope if enabled
   if (Settings.SuperScopeMaster)
      ProcessSuperScope();

   if (Memory.FillRAM [0x4200] & 1)
   {
      PPU.Joypad1ButtonReadPos = 16;
      if (Memory.FillRAM [0x4201] & 0x80)
      {
         PPU.Joypad2ButtonReadPos = 16;
         PPU.Joypad3ButtonReadPos = 0;
      }
      else
      {
         PPU.Joypad2ButtonReadPos = 0;
         PPU.Joypad3ButtonReadPos = 16;
      }

      Memory.FillRAM [0x4218] = (uint8_t) IPPU.Joypads [0];
      Memory.FillRAM [0x4219] = (uint8_t)(IPPU.Joypads [0] >> 8);
      Memory.FillRAM [0x421a] = (uint8_t) IPPU.Joypads [1];
      Memory.FillRAM [0x421b] = (uint8_t)(IPPU.Joypads [1] >> 8);
      if (Memory.FillRAM [0x4201] & 0x80)
      {
         Memory.FillRAM [0x421c] = (uint8_t) IPPU.Joypads [0];
         Memory.FillRAM [0x421d] = (uint8_t)(IPPU.Joypads [0] >> 8);
         Memory.FillRAM [0x421e] = (uint8_t) IPPU.Joypads [2];
         Memory.FillRAM [0x421f] = (uint8_t)(IPPU.Joypads [2] >> 8);
      }
      else
      {
         Memory.FillRAM [0x421c] = (uint8_t) IPPU.Joypads [3];
         Memory.FillRAM [0x421d] = (uint8_t)(IPPU.Joypads [3] >> 8);
         Memory.FillRAM [0x421e] = (uint8_t) IPPU.Joypads [4];
         Memory.FillRAM [0x421f] = (uint8_t)(IPPU.Joypads [4] >> 8);
      }
   }
   if (Settings.Justifier || Settings.SecondJustifier)
   {
      Memory.FillRAM [0x421a] = 0x0E;
      Memory.FillRAM [0x421b] = 0;
      S9xUpdateJustifiers();
   }

}


void S9xSuperFXExec()
{
   if (Settings.SuperFX)
   {
      if ((Memory.FillRAM [0x3000 + GSU_SFR] & FLG_G) &&
            (Memory.FillRAM [0x3000 + GSU_SCMR] & 0x18) == 0x18)
      {
         if (!Settings.WinterGold || Settings.StarfoxHack)
            FxEmulate(~0);
         else
            FxEmulate((Memory.FillRAM [0x3000 + GSU_CLSR] & 1) ? 700 : 350);
         int32_t GSUStatus = Memory.FillRAM [0x3000 + GSU_SFR] |
                             (Memory.FillRAM [0x3000 + GSU_SFR + 1] << 8);
         if ((GSUStatus & (FLG_G | FLG_IRQ)) == FLG_IRQ)
         {
            // Trigger a GSU IRQ.
            S9xSetIRQ(GSU_IRQ_SOURCE);
         }
      }
   }
}

// Register reads and writes...

uint8_t REGISTER_4212()
{
   uint8_t GetBank = 0;
   if (CPU.V_Counter >= PPU.ScreenHeight + FIRST_VISIBLE_LINE &&
         CPU.V_Counter < PPU.ScreenHeight + FIRST_VISIBLE_LINE + 3)
      GetBank = 1;

   GetBank |= CPU.Cycles >= Settings.HBlankStart ? 0x40 : 0;
   if (CPU.V_Counter >= PPU.ScreenHeight + FIRST_VISIBLE_LINE)
      GetBank |= 0x80; /* XXX: 0x80 or 0xc0 ? */

   return (GetBank);
}

void FLUSH_REDRAW()
{
   if (IPPU.PreviousLine != IPPU.CurrentLine)
      S9xUpdateScreen();
}

void REGISTER_2104(uint8_t byte)
{
   if (PPU.OAMAddr & 0x100)
   {
      int32_t addr = ((PPU.OAMAddr & 0x10f) << 1) + (PPU.OAMFlip & 1);
      if (byte != PPU.OAMData [addr])
      {
         FLUSH_REDRAW();
         PPU.OAMData [addr] = byte;
         IPPU.OBJChanged = true;

         // X position high bit, and sprite size (x4)
         struct SOBJ* pObj = &PPU.OBJ [(addr & 0x1f) * 4];

         pObj->HPos = (pObj->HPos & 0xFF) | SignExtend[(byte >> 0) & 1];
         pObj++->Size = byte & 2;
         pObj->HPos = (pObj->HPos & 0xFF) | SignExtend[(byte >> 2) & 1];
         pObj++->Size = byte & 8;
         pObj->HPos = (pObj->HPos & 0xFF) | SignExtend[(byte >> 4) & 1];
         pObj++->Size = byte & 32;
         pObj->HPos = (pObj->HPos & 0xFF) | SignExtend[(byte >> 6) & 1];
         pObj->Size = byte & 128;
      }
      PPU.OAMFlip ^= 1;
      if (!(PPU.OAMFlip & 1))
      {
         ++PPU.OAMAddr;
         PPU.OAMAddr &= 0x1ff;
         if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
         {
            PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
            IPPU.OBJChanged = true;
         }
      }
      else
      {
         if (PPU.OAMPriorityRotation && (PPU.OAMAddr & 1)) IPPU.OBJChanged = true;
      }
   }
   else if (!(PPU.OAMFlip & 1))
   {
      PPU.OAMWriteRegister &= 0xff00;
      PPU.OAMWriteRegister |= byte;
      PPU.OAMFlip |= 1;
      if (PPU.OAMPriorityRotation && (PPU.OAMAddr & 1)) IPPU.OBJChanged = true;
   }
   else
   {
      PPU.OAMWriteRegister &= 0x00ff;
      uint8_t lowbyte = (uint8_t)(PPU.OAMWriteRegister);
      uint8_t highbyte = byte;
      PPU.OAMWriteRegister |= byte << 8;

      int32_t addr = (PPU.OAMAddr << 1);

      if (lowbyte != PPU.OAMData [addr] ||
            highbyte != PPU.OAMData [addr + 1])
      {
         FLUSH_REDRAW();
         PPU.OAMData [addr] = lowbyte;
         PPU.OAMData [addr + 1] = highbyte;
         IPPU.OBJChanged = true;
         if (addr & 2)
         {
            // Tile
            PPU.OBJ[addr = PPU.OAMAddr >> 1].Name = PPU.OAMWriteRegister & 0x1ff;

            // priority, h and v flip.
            PPU.OBJ[addr].Palette = (highbyte >> 1) & 7;
            PPU.OBJ[addr].Priority = (highbyte >> 4) & 3;
            PPU.OBJ[addr].HFlip = (highbyte >> 6) & 1;
            PPU.OBJ[addr].VFlip = (highbyte >> 7) & 1;
         }
         else
         {
            // X position (low)
            PPU.OBJ[addr = PPU.OAMAddr >> 1].HPos &= 0xFF00;
            PPU.OBJ[addr].HPos |= lowbyte;

            // Sprite Y position
            PPU.OBJ[addr].VPos = highbyte;
         }
      }
      PPU.OAMFlip &= ~1;
      ++PPU.OAMAddr;
      if (PPU.OAMPriorityRotation && PPU.FirstSprite != (PPU.OAMAddr >> 1))
      {
         PPU.FirstSprite = (PPU.OAMAddr & 0xFE) >> 1;
         IPPU.OBJChanged = true;
      }
   }

   Memory.FillRAM [0x2104] = byte;
}

void REGISTER_2118(uint8_t Byte)
{
   uint32_t address;
   if (PPU.VMA.FullGraphicCount)
   {
      uint32_t rem = PPU.VMA.Address & PPU.VMA.Mask1;
      address = (((PPU.VMA.Address & ~PPU.VMA.Mask1) +
                  (rem >> PPU.VMA.Shift) +
                  ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3)) << 1) & 0xffff;
      Memory.VRAM [address] = Byte;
   }
   else
      Memory.VRAM[address = (PPU.VMA.Address << 1) & 0xFFFF] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (!PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2118_tile(uint8_t Byte)
{
   uint32_t address;
   uint32_t rem = PPU.VMA.Address & PPU.VMA.Mask1;
   address = (((PPU.VMA.Address & ~PPU.VMA.Mask1) +
               (rem >> PPU.VMA.Shift) +
               ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3)) << 1) & 0xffff;
   Memory.VRAM [address] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (!PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2118_linear(uint8_t Byte)
{
   uint32_t address;
   Memory.VRAM[address = (PPU.VMA.Address << 1) & 0xFFFF] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (!PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2119(uint8_t Byte)
{
   uint32_t address;
   if (PPU.VMA.FullGraphicCount)
   {
      uint32_t rem = PPU.VMA.Address & PPU.VMA.Mask1;
      address = ((((PPU.VMA.Address & ~PPU.VMA.Mask1) +
                   (rem >> PPU.VMA.Shift) +
                   ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3)) << 1) + 1) & 0xFFFF;
      Memory.VRAM [address] = Byte;
   }
   else
      Memory.VRAM[address = ((PPU.VMA.Address << 1) + 1) & 0xFFFF] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2119_tile(uint8_t Byte)
{
   uint32_t rem = PPU.VMA.Address & PPU.VMA.Mask1;
   uint32_t address = ((((PPU.VMA.Address & ~PPU.VMA.Mask1) +
                       (rem >> PPU.VMA.Shift) +
                       ((rem & (PPU.VMA.FullGraphicCount - 1)) << 3)) << 1) + 1) & 0xFFFF;
   Memory.VRAM [address] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2119_linear(uint8_t Byte)
{
   uint32_t address;
   Memory.VRAM[address = ((PPU.VMA.Address << 1) + 1) & 0xFFFF] = Byte;
   IPPU.TileCached [TILE_2BIT][address >> 4] = false;
   IPPU.TileCached [TILE_4BIT][address >> 5] = false;
   IPPU.TileCached [TILE_8BIT][address >> 6] = false;
   if (PPU.VMA.High)
      PPU.VMA.Address += PPU.VMA.Increment;
}

void REGISTER_2122(uint8_t Byte)
{
   // CG-RAM (palette) write

   if (PPU.CGFLIP)
   {
      if ((Byte & 0x7f) != (PPU.CGDATA[PPU.CGADD] >> 8))
      {
         FLUSH_REDRAW();
         PPU.CGDATA[PPU.CGADD] &= 0x00FF;
         PPU.CGDATA[PPU.CGADD] |= (Byte & 0x7f) << 8;
         IPPU.ColorsChanged = true;
         IPPU.Blue [PPU.CGADD] = IPPU.XB [(Byte >> 2) & 0x1f];
         IPPU.Green [PPU.CGADD] = IPPU.XB [(PPU.CGDATA[PPU.CGADD] >> 5) & 0x1f];
         IPPU.ScreenColors [PPU.CGADD] = (uint16_t) BUILD_PIXEL(IPPU.Red [PPU.CGADD],
                                         IPPU.Green [PPU.CGADD],
                                         IPPU.Blue [PPU.CGADD]);
      }
      PPU.CGADD++;
   }
   else
   {
      if (Byte != (uint8_t)(PPU.CGDATA[PPU.CGADD] & 0xff))
      {
         FLUSH_REDRAW();
         PPU.CGDATA[PPU.CGADD] &= 0x7F00;
         PPU.CGDATA[PPU.CGADD] |= Byte;
         IPPU.ColorsChanged = true;
         IPPU.Red [PPU.CGADD] = IPPU.XB [Byte & 0x1f];
         IPPU.Green [PPU.CGADD] = IPPU.XB [(PPU.CGDATA[PPU.CGADD] >> 5) & 0x1f];
         IPPU.ScreenColors [PPU.CGADD] = (uint16_t) BUILD_PIXEL(IPPU.Red [PPU.CGADD],
                                         IPPU.Green [PPU.CGADD],
                                         IPPU.Blue [PPU.CGADD]);
      }
   }
   PPU.CGFLIP ^= 1;
}

void REGISTER_2180(uint8_t Byte)
{
   Memory.RAM[PPU.WRAM++] = Byte;
   PPU.WRAM &= 0x1FFFF;
   Memory.FillRAM [0x2180] = Byte;
}