Updates to BUS

Add digital sample support to BUS.

src/debugger/gui/CartBUSWidget.cxx

@@ -279,8 +279,8 @@ void CartridgeBUSWidget::loadConfig()
   }
   myMusicWaveformSizes->setList(alist, vlist, changed);
 
-  myBusOverdrive->setState(myCart.getBusStuffFlag());
+//  myBusOverdrive->setState(myCart.getBusStuffFlag());
-  myZPSTY->setState(myCart.mySTYZeroPage);
+//  myZPSTY->setState(myCart.mySTYZeroPage);
 
   CartDebugWidget::loadConfig();
 }

src/emucore/CartBUS.cxx

@@ -33,6 +33,8 @@
 #define WAVEFORM      0x07F4
 #define DSRAM         0x0800
 
+#define BUS_STUFF_ON ((myMode & 0x0F) == 0)
+#define DIGITAL_AUDIO_ON ((myMode & 0xF0) == 0)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 CartridgeBUS::CartridgeBUS(const uInt8* image, uInt32 size,
@@ -63,12 +65,6 @@ CartridgeBUS::CartridgeBUS(const uInt8* image, uInt32 size,
     settings.getBool("thumb.trapfatal"), Thumbulator::ConfigureFor::BUS, this);
 #endif
   setInitialState();
-
-  // BUS always starts in bank 6
-  myStartBank = 6;
-
-  // bus stuffing is off by default
-  myBusStuff = false;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -98,6 +94,13 @@ void CartridgeBUS::setInitialState()
 
   for (int i=0; i < 3; ++i)
     myMusicWaveformSize[i] = 27;
+  
+  // BUS always starts in bank 6
+  myStartBank = 6;
+  
+  // Assuming mode starts out with Fast Fetch off and 3-Voice music,
+  // need to confirm with Chris
+  myMode = 0xFF;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -210,10 +213,10 @@ uInt8 CartridgeBUS::peek(uInt16 address)
       return peekvalue;
 
     // save the STY's zero page address
-    if (getBusStuffFlag() && mySTYZeroPage)
+    if (BUS_STUFF_ON && mySTYZeroPageAddress == address)
       myBusOverdriveAddress =  peekvalue;
 
-    mySTYZeroPage = false;
+    mySTYZeroPageAddress = 0;
 
     if(address < 0x20)
     {
@@ -251,13 +254,26 @@ uInt8 CartridgeBUS::peek(uInt16 address)
               // Update the music data fetchers (counter & flag)
               updateMusicModeDataFetchers();
 
-              // using myDisplayImage[] instead of myProgramImage[] because waveforms
+              if DIGITAL_AUDIO_ON
-              // can be modified during runtime.
+              {
-              uInt32 i = myDisplayImage[(getWaveform(0) ) + (myMusicCounters[0] >> myMusicWaveformSize[0])] +
+                // retrieve packed sample (max size is 2K, or 4K of unpacked data)
-              myDisplayImage[(getWaveform(1) ) + (myMusicCounters[1] >> myMusicWaveformSize[1])] +
+                result = myImage[getSample() + (myMusicCounters[0] >> 21)];
-              myDisplayImage[(getWaveform(2) ) + (myMusicCounters[2] >> myMusicWaveformSize[2])];
+                
-
+                //
-              result = uInt8(i);
+                if ((myMusicCounters[0] & (1<<20)) == 0)
+                  result >>= 4;
+                result &= 0x0f;
+              }
+              else
+              {
+                // using myDisplayImage[] instead of myProgramImage[] because waveforms
+                // can be modified during runtime.
+                uInt32 i = myDisplayImage[(getWaveform(0) ) + (myMusicCounters[0] >> myMusicWaveformSize[0])] +
+                myDisplayImage[(getWaveform(1) ) + (myMusicCounters[1] >> myMusicWaveformSize[1])] +
+                myDisplayImage[(getWaveform(2) ) + (myMusicCounters[2] >> myMusicWaveformSize[2])];
+                
+                result = uInt8(i);
+              }
               break;
           }
           break;
@@ -311,8 +327,8 @@ uInt8 CartridgeBUS::peek(uInt16 address)
       }
 
       // this might not work right for STY $84
-      if (getBusStuffFlag())
+      if (BUS_STUFF_ON && peekvalue == 0x84)
-        mySTYZeroPage = (peekvalue == 0x84);
+        mySTYZeroPageAddress = address + 1;
 
       return peekvalue;
     }
@@ -381,8 +397,8 @@ bool CartridgeBUS::poke(uInt16 address, uInt8 value)
           setDatastreamPointer(index, pointer);
           break;
 
-        case 0x09:  // 0x19 turn on STY ZP bus stuffing if value is 0
+        case 0x09:  // 0x19 SETMODE
-          setBusStuffFlag(value==0);
+          myMode = value;
           break;
 
         case 0x0A:  // 0x1A CALLFUNCTION
@@ -683,10 +699,10 @@ uInt32 CartridgeBUS::getWaveform(uInt8 index) const
 
   uInt32 result;
 
-  result = myBUSRAM[WAVEFORM + index*4 + 0]        +   // low byte
+  result = myBUSRAM[WAVEFORM + index*4 + 0]        +  // low byte
           (myBUSRAM[WAVEFORM + index*4 + 1] << 8)  +
           (myBUSRAM[WAVEFORM + index*4 + 2] << 16) +
-          (myBUSRAM[WAVEFORM + index*4 + 3] << 24);
+          (myBUSRAM[WAVEFORM + index*4 + 3] << 24);   // high byte
 
   result -= 0x40000800;
 
@@ -696,6 +712,19 @@ uInt32 CartridgeBUS::getWaveform(uInt8 index) const
   return result;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 CartridgeBUS::getSample()
+{
+  uInt32 result;
+  
+  result = myBUSRAM[WAVEFORM + 0]        +  // low byte
+          (myBUSRAM[WAVEFORM + 1] << 8)  +
+          (myBUSRAM[WAVEFORM + 2] << 16) +
+          (myBUSRAM[WAVEFORM + 3] << 24);   // high byte
+  
+  return result;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt32 CartridgeBUS::getWaveformSize(uInt8 index) const
 {
@@ -712,18 +741,6 @@ void CartridgeBUS::setAddressMap(uInt8 index, uInt32 value)
   myBUSRAM[DSMAPS + index*4 + 3] = (value >> 24) & 0xff;  // high byte
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool CartridgeBUS::getBusStuffFlag(void) const
-{
-  return myBusStuff;
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void CartridgeBUS::setBusStuffFlag(bool value)
-{
-  myBusStuff = value;
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt8 CartridgeBUS::readFromDatastream(uInt8 index)
 {

src/emucore/CartBUS.hxx

@@ -208,13 +208,11 @@ class CartridgeBUS : public Cartridge
     uInt32 getAddressMap(uInt8 index) const;
     void setAddressMap(uInt8 index, uInt32 value);
 
-    bool getBusStuffFlag(void) const;
-    void setBusStuffFlag(bool value);
-
     uInt8 readFromDatastream(uInt8 index);
 
     uInt32 getWaveform(uInt8 index) const;
     uInt32 getWaveformSize(uInt8 index) const;
+    uInt32 getSample();
 
   private:
     // The 32K ROM image of the cartridge
@@ -246,8 +244,8 @@ class CartridgeBUS : public Cartridge
     // Address to override the bus for
     uInt16 myBusOverdriveAddress;
 
-    // Flags that last byte peeked was 84 (STY ZP)
+    // set to address of ZP if last byte peeked was $84 (STY ZP)
-    bool mySTYZeroPage;
+    uInt16 mySTYZeroPageAddress;
 
     // System cycle count when the last update to music data fetchers occurred
     Int32 mySystemCycles;
@@ -266,8 +264,12 @@ class CartridgeBUS : public Cartridge
     // Fractional DPC music OSC clocks unused during the last update
     double myFractionalClocks;
 
-    // Flags that Bus Stuffing is active
+    // Controls mode, lower nybble sets Fast Fetch, upper nybble sets audio
-    bool myBusStuff;
+    // -0 = Bus Stuffing ON
+    // -F = Bus Stuffing OFF
+    // 0- = Packed Digital Sample
+    // F- = 3 Voice Music
+    uInt8 myMode;
 
   private:
     // Following constructors and assignment operators not supported