v108.15

Add "No VRAM Blocking" and "Echo Shadow RAM" options:
These allow compatibility with very old ROM hacks that
only previously ran in ZSNES and earlier Snes9X releases.

bsnes/emulator/emulator.hpp

@@ -29,7 +29,7 @@ using namespace nall;
 
 namespace Emulator {
   static const string Name    = "bsnes";
-  static const string Version = "108.14";
+  static const string Version = "108.15";
   static const string Author  = "byuu";
   static const string License = "GPLv3";
   static const string Website = "https://byuu.org";

bsnes/sfc/dsp/SPC_DSP.cpp

@@ -612,7 +612,7 @@ VOICE_CLOCK(V9_V6_V3) { voice_V9(v); voice_V6(v+1); voice_V3(v+2); }
 //// Echo
 
 // Current echo buffer pointer for left/right channel
-#define ECHO_PTR( ch )      (&m.ram [m.t_echo_ptr + ch * 2])
+#define ECHO_PTR( ch )      (&m.echo [m.t_echo_ptr + ch * 2])
 
 // Sample in echo history buffer, where 0 is the oldest
 #define ECHO_FIR( i )       (m.echo_hist_pos [i])
@@ -835,9 +835,10 @@ void SPC_DSP::run( int clocks_remain )
 
 //// Setup
 
-void SPC_DSP::init( void* ram_64k )
+void SPC_DSP::init( void* ram_64k, void* echo_64k )
 {
-	m.ram = (uint8_t*) ram_64k;
+	m.ram  = (uint8_t*) ram_64k;
+    m.echo = (uint8_t*) echo_64k;
 	mute_voices( 0 );
 	disable_surround( false );
 	set_output( 0, 0 );
@@ -861,7 +862,8 @@ void SPC_DSP::init( void* ram_64k )
 
 void SPC_DSP::soft_reset_common()
 {
-	require( m.ram ); // init() must have been called already
+	require( m.ram  ); // init() must have been called already
+	require( m.echo );
 	
 	m.noise              = 0x4000;
 	m.echo_hist_pos      = m.echo_hist;

bsnes/sfc/dsp/SPC_DSP.h

@@ -15,7 +15,7 @@ public:
 // Setup
 
 	// Initializes DSP and has it use the 64K RAM provided
-	void init( void* ram_64k );
+	void init( void* ram_64k, void* echo_64k );
 
 	// Sets destination for output samples. If out is NULL or out_size is 0,
 	// doesn't generate any.
@@ -178,7 +178,8 @@ private:
 		voice_t voices [voice_count];
 		
 		// non-emulation state
-		uint8_t* ram; // 64K shared RAM between DSP and SMP
+		uint8_t* ram;   // 64K shared RAM between DSP and SMP
+		uint8_t* echo;  // should point at the same memory as ram; used for older hack compatibility
 		int mute_mask;
 		sample_t* out;
 		sample_t* out_end;

bsnes/sfc/dsp/dsp.cpp

@@ -30,6 +30,12 @@ auto DSP::read(uint8 address) -> uint8 {
 }
 
 auto DSP::write(uint8 address, uint8 data) -> void {
+  if(configuration.hacks.dsp.echoShadow) {
+    if(address == 0x6c && (data & 0x20)) {
+      memset(echoram, 0x00, 65536);
+    }
+  }
+
   spc_dsp.write(address, data);
 }
 
@@ -42,7 +48,12 @@ auto DSP::power(bool reset) -> void {
   stream = Emulator::audio.createStream(2, system.apuFrequency() / 768.0);
 
   if(!reset) {
-    spc_dsp.init(apuram);
+    if(!configuration.hacks.dsp.echoShadow) {
+      spc_dsp.init(apuram, apuram);
+    } else {
+      memset(echoram, 0x00, 65536);
+      spc_dsp.init(apuram, echoram);
+    }
     spc_dsp.reset();
     spc_dsp.set_output(samplebuffer, 8192);
   } else {

bsnes/sfc/dsp/dsp.hpp

@@ -20,6 +20,9 @@ private:
   bool fastDSP = false;
   SPC_DSP spc_dsp;
   int16 samplebuffer[8192];
+
+//unserialized:
+  uint8 echoram[64 * 1024] = {};
 };
 
 extern DSP dsp;

bsnes/sfc/interface/configuration.cpp

@@ -22,12 +22,14 @@ auto Configuration::process(Markup::Node document, bool load) -> void {
   bind(boolean, "Hacks/PPU/Deinterlace", hacks.ppu.deinterlace);
   bind(natural, "Hacks/PPU/RenderCycle", hacks.ppu.renderCycle);
   bind(boolean, "Hacks/PPU/NoSpriteLimit", hacks.ppu.noSpriteLimit);
+  bind(boolean, "Hacks/PPU/NoVRAMBlocking", hacks.ppu.noVRAMBlocking);
   bind(natural, "Hacks/PPU/Mode7/Scale", hacks.ppu.mode7.scale);
   bind(boolean, "Hacks/PPU/Mode7/Perspective", hacks.ppu.mode7.perspective);
   bind(boolean, "Hacks/PPU/Mode7/Supersample", hacks.ppu.mode7.supersample);
   bind(boolean, "Hacks/PPU/Mode7/Mosaic", hacks.ppu.mode7.mosaic);
   bind(boolean, "Hacks/DSP/Fast", hacks.dsp.fast);
   bind(boolean, "Hacks/DSP/Cubic", hacks.dsp.cubic);
+  bind(boolean, "Hacks/DSP/EchoShadow", hacks.dsp.echoShadow);
   bind(boolean, "Hacks/Coprocessor/DelayedSync", hacks.coprocessor.delayedSync);
   bind(boolean, "Hacks/Coprocessor/PreferHLE", hacks.coprocessor.preferHLE);
   bind(natural, "Hacks/SA1/Overclock", hacks.sa1.overclock);

bsnes/sfc/interface/configuration.hpp

@@ -33,6 +33,7 @@ struct Configuration {
       bool fast = true;
       bool deinterlace = true;
       bool noSpriteLimit = false;
+      bool noVRAMBlocking = false;
       uint renderCycle = 512;
       struct Mode7 {
         uint scale = 1;
@@ -44,6 +45,7 @@ struct Configuration {
     struct DSP {
       bool fast = true;
       bool cubic = false;
+      bool echoShadow = false;
     } dsp;
     struct Coprocessor {
       bool delayedSync = true;

bsnes/sfc/ppu-fast/io.cpp

@@ -29,7 +29,7 @@ auto PPU::readVRAM() -> uint16 {
 
 template<bool Byte>
 auto PPU::writeVRAM(uint8 data) -> void {
-  if(!io.displayDisable && cpu.vcounter() < vdisp()) return;
+  if(!io.displayDisable && cpu.vcounter() < vdisp() && !noVRAMBlocking()) return;
   Line::flush();
   auto address = vramAddress();
   if constexpr(Byte == 0) {

bsnes/sfc/ppu-fast/ppu.cpp

@@ -30,6 +30,7 @@ auto PPU::hdSupersample() const -> bool { return configuration.hacks.ppu.mode7.s
 auto PPU::hdMosaic() const -> bool { return configuration.hacks.ppu.mode7.mosaic; }
 auto PPU::deinterlace() const -> bool { return configuration.hacks.ppu.deinterlace; }
 auto PPU::renderCycle() const -> uint { return configuration.hacks.ppu.renderCycle; }
+auto PPU::noVRAMBlocking() const -> bool { return configuration.hacks.ppu.noVRAMBlocking; }
 #define ppu ppufast
 
 PPU::PPU() {

bsnes/sfc/ppu-fast/ppu.hpp

@@ -20,6 +20,7 @@ struct PPU : PPUcounter {
   alwaysinline auto hdMosaic() const -> bool;
   alwaysinline auto deinterlace() const -> bool;
   alwaysinline auto renderCycle() const -> uint;
+  alwaysinline auto noVRAMBlocking() const -> bool;
 
   //ppu.cpp
   PPU();

bsnes/target-bsnes/program/game.cpp

@@ -6,12 +6,14 @@ auto Program::load() -> void {
   emulator->configure("Hacks/PPU/Fast", settings.emulator.hack.ppu.fast);
   emulator->configure("Hacks/PPU/Deinterlace", settings.emulator.hack.ppu.deinterlace);
   emulator->configure("Hacks/PPU/NoSpriteLimit", settings.emulator.hack.ppu.noSpriteLimit);
+  emulator->configure("Hacks/PPU/NoVRAMBlocking", settings.emulator.hack.ppu.noVRAMBlocking);
   emulator->configure("Hacks/PPU/Mode7/Scale", settings.emulator.hack.ppu.mode7.scale);
   emulator->configure("Hacks/PPU/Mode7/Perspective", settings.emulator.hack.ppu.mode7.perspective);
   emulator->configure("Hacks/PPU/Mode7/Supersample", settings.emulator.hack.ppu.mode7.supersample);
   emulator->configure("Hacks/PPU/Mode7/Mosaic", settings.emulator.hack.ppu.mode7.mosaic);
   emulator->configure("Hacks/DSP/Fast", settings.emulator.hack.dsp.fast);
   emulator->configure("Hacks/DSP/Cubic", settings.emulator.hack.dsp.cubic);
+  emulator->configure("Hacks/DSP/EchoShadow", settings.emulator.hack.dsp.echoShadow);
   emulator->configure("Hacks/Coprocessor/DelayedSync", settings.emulator.hack.coprocessor.delayedSync);
   emulator->configure("Hacks/Coprocessor/PreferHLE", settings.emulator.hack.coprocessor.preferHLE);
   emulator->configure("Hacks/SuperFX/Overclock", settings.emulator.hack.superfx.overclock);

bsnes/target-bsnes/settings/emulator.cpp

@@ -65,6 +65,15 @@ auto EmulatorSettings::create() -> void {
   noSpriteLimit.setText("No sprite limit").setChecked(settings.emulator.hack.ppu.noSpriteLimit).onToggle([&] {
     settings.emulator.hack.ppu.noSpriteLimit = noSpriteLimit.checked();
   });
+  noVRAMBlocking.setText("No VRAM blocking").setToolTip(
+    "This option emulates a bug in older releases of ZSNES and Snes9X where VRAM blocking was not emulated.\n"
+    "A few older ROM hacks relied on this behavior, and will render graphics incorrectly if not enabled.\n"
+    "Not only is this extremely inaccurate to real hardware, it also hurts the speed of the fast PPU.\n"
+    "Do not enable this option unless you need to play a game that is incompatible with bsnes otherwise."
+  ).setChecked(settings.emulator.hack.ppu.noVRAMBlocking).onToggle([&] {
+    settings.emulator.hack.ppu.noVRAMBlocking = noVRAMBlocking.checked();
+    emulator->configure("Hacks/PPU/NoVRAMBlocking", settings.emulator.hack.ppu.noVRAMBlocking);
+  });
   mode7Label.setText("HD Mode 7 (fast PPU only)").setFont(Font().setBold());
   mode7ScaleLabel.setText("Scale:");
   mode7Scale.append(ComboButtonItem().setText( "240p").setProperty("multiplier", 1));
@@ -104,6 +113,14 @@ auto EmulatorSettings::create() -> void {
     settings.emulator.hack.dsp.cubic = cubicInterpolation.checked();
     emulator->configure("Hacks/DSP/Cubic", settings.emulator.hack.dsp.cubic);
   });
+  echoShadow.setText("Echo shadow RAM").setToolTip(
+    "This option emulates a bug in ZSNES where echo RAM was treated as separate from APU RAM.\n"
+    "Many older ROM hacks for Super Mario World relied on this behavior, and will crash without enabling this.\n"
+    "It is, however, extremely inaccurate to real hardware and should not be enabled unless required."
+  ).setChecked(settings.emulator.hack.dsp.echoShadow).onToggle([&] {
+    settings.emulator.hack.dsp.echoShadow = echoShadow.checked();
+    //not a run-time setting: do not call emulator->configure() here.
+  });
   coprocessorLabel.setText("Coprocessors").setFont(Font().setBold());
   coprocessorDelayedSyncOption.setText("Fast mode").setChecked(settings.emulator.hack.coprocessor.delayedSync).onToggle([&] {
     settings.emulator.hack.coprocessor.delayedSync = coprocessorDelayedSyncOption.checked();

bsnes/target-bsnes/settings/settings.cpp

@@ -117,12 +117,14 @@ auto Settings::process(bool load) -> void {
   bind(boolean, "Emulator/Hack/PPU/Fast",                emulator.hack.ppu.fast);
   bind(boolean, "Emulator/Hack/PPU/Deinterlace",         emulator.hack.ppu.deinterlace);
   bind(boolean, "Emulator/Hack/PPU/NoSpriteLimit",       emulator.hack.ppu.noSpriteLimit);
+  bind(boolean, "Emulator/Hack/PPU/NoVRAMBlocking",      emulator.hack.ppu.noVRAMBlocking);
   bind(natural, "Emulator/Hack/PPU/Mode7/Scale",         emulator.hack.ppu.mode7.scale);
   bind(boolean, "Emulator/Hack/PPU/Mode7/Perspective",   emulator.hack.ppu.mode7.perspective);
   bind(boolean, "Emulator/Hack/PPU/Mode7/Supersample",   emulator.hack.ppu.mode7.supersample);
   bind(boolean, "Emulator/Hack/PPU/Mode7/Mosaic",        emulator.hack.ppu.mode7.mosaic);
   bind(boolean, "Emulator/Hack/DSP/Fast",                emulator.hack.dsp.fast);
   bind(boolean, "Emulator/Hack/DSP/Cubic",               emulator.hack.dsp.cubic);
+  bind(boolean, "Emulator/Hack/DSP/EchoShadow",          emulator.hack.dsp.echoShadow);
   bind(boolean, "Emulator/Hack/Coprocessor/DelayedSync", emulator.hack.coprocessor.delayedSync);
   bind(boolean, "Emulator/Hack/Coprocessor/PreferHLE",   emulator.hack.coprocessor.preferHLE);
   bind(natural, "Emulator/Hack/SA1/Overclock",           emulator.hack.sa1.overclock);

bsnes/target-bsnes/settings/settings.hpp

@@ -103,6 +103,7 @@ struct Settings : Markup::Node {
         bool fast = true;
         bool deinterlace = true;
         bool noSpriteLimit = false;
+        bool noVRAMBlocking = false;
         struct Mode7 {
           uint scale = 1;
           bool perspective = true;
@@ -113,6 +114,7 @@ struct Settings : Markup::Node {
       struct DSP {
         bool fast = true;
         bool cubic = false;
+        bool echoShadow = false;
       } dsp;
       struct Coprocessor {
         bool delayedSync = true;
@@ -343,6 +345,7 @@ public:
     CheckLabel fastPPU{&ppuLayout, Size{0, 0}};
     CheckLabel deinterlace{&ppuLayout, Size{0, 0}};
     CheckLabel noSpriteLimit{&ppuLayout, Size{0, 0}};
+    CheckLabel noVRAMBlocking{&ppuLayout, Size{0, 0}};
   Label mode7Label{this, Size{~0, 0}, 2};
   HorizontalLayout mode7Layout{this, Size{~0, 0}};
     Label mode7ScaleLabel{&mode7Layout, Size{0, 0}};
@@ -354,6 +357,7 @@ public:
   HorizontalLayout dspLayout{this, Size{~0, 0}};
     CheckLabel fastDSP{&dspLayout, Size{0, 0}};
     CheckLabel cubicInterpolation{&dspLayout, Size{0, 0}};
+    CheckLabel echoShadow{&dspLayout, Size{0, 0}};
   Label coprocessorLabel{this, Size{~0, 0}, 2};
   HorizontalLayout coprocessorLayout{this, Size{~0, 0}};
     CheckLabel coprocessorDelayedSyncOption{&coprocessorLayout, Size{0, 0}};