improve bankswitching masking in CartEnhanced

src/emucore/Cart3F.hxx

@@ -87,6 +87,8 @@ class Cartridge3F : public CartridgeEnhanced
   private:
     bool checkSwitchBank(uInt16 address, uInt8 value) override;
 
+    uInt16 hotspot() const override { return 0x003F; }
+
   private:
     // log(ROM bank segment size) / log(2)
     static constexpr uInt16 BANK_SHIFT = 11; // = 2K = 0x0800

src/emucore/CartE0.cxx

@@ -48,6 +48,8 @@ void CartridgeE0::reset()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool CartridgeE0::checkSwitchBank(uInt16 address, uInt8)
 {
+  address &= ROM_MASK;
+
   // Switch banks if necessary
   if((address >= 0x0FE0) && (address <= 0x0FE7))
   {

src/emucore/CartEnhanced.cxx

@@ -114,8 +114,9 @@ uInt8 CartridgeEnhanced::peek(uInt16 address)
 {
   uInt16 peekAddress = address;
 
-  if (hotspot() != 0)
-    checkSwitchBank(address & ROM_MASK);
+  // hotspots in TIA range are reacting to pokes only
+  if (hotspot() >= 0x80)
+    checkSwitchBank(address & ADDR_MASK);
 
   if(isRamBank(address))
   {
@@ -148,7 +149,7 @@ bool CartridgeEnhanced::poke(uInt16 address, uInt8 value)
   // Note: (TODO?)
   //   The checkSwitchBank() call makes no difference between ROM and e.g TIA space
   //   Writing to e.g. 0xf0xx might triger a bankswitch, is (and was!) this a bug???
-  if (checkSwitchBank(address & ROM_MASK, value))
+  if (checkSwitchBank(address & ADDR_MASK, value))
     return false;
 
   if(myRamSize > 0)

src/emucore/CartEnhanced.hxx

@@ -232,6 +232,9 @@ class CartridgeEnhanced : public Cartridge
     size_t mySize{0};
 
   protected:
+    // The mask for 6507 address space
+    static constexpr uInt16 ADDR_MASK = 0x1FFF;
+
     // The offset into address space for accessing ROM
     static constexpr uInt16 ROM_OFFSET = 0x1000;
 

src/emucore/CartF0.cxx

@@ -28,7 +28,7 @@ CartridgeF0::CartridgeF0(const ByteBuffer& image, size_t size,
 bool CartridgeF0::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
-  if(address == 0x0FF0)
+  if(address == 0x1FF0)
   {
     // Switch to next bank
     uInt8 nextBank = ((getBank()) + 1) & 0x0F;

src/emucore/CartF4.cxx

@@ -29,9 +29,9 @@ bool CartridgeF4::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
   // Note: addresses could be calculated from hotspot and bank count
-  if((address >= 0x0FF4) && (address <= 0x0FFB))
+  if((address >= 0x1FF4) && (address <= 0x1FFB))
   {
-    bank(address - 0x0FF4);
+    bank(address - 0x1FF4);
     return true;
   }
   return false;

src/emucore/CartF6.cxx

@@ -29,9 +29,9 @@ bool CartridgeF6::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
   // Note: addresses could be calculated from hotspot and bank count
-  if((address >= 0x0FF6) && (address <= 0x0FF9))
+  if((address >= 0x1FF6) && (address <= 0x1FF9))
   {
-    bank(address - 0x0FF6);
+    bank(address - 0x1FF6);
     return true;
   }
   return false;

src/emucore/CartF8.cxx

@@ -30,12 +30,12 @@ bool CartridgeF8::checkSwitchBank(uInt16 address, uInt8)
   // Switch banks if necessary
   switch(address)
   {
-    case 0x0FF8:
+    case 0x1FF8:
       // Set the current bank to the lower 4k bank
       bank(0);
       return true;
 
-    case 0x0FF9:
+    case 0x1FF9:
       // Set the current bank to the upper 4k bank
       bank(1);
       return true;

src/emucore/CartFA.cxx

@@ -30,9 +30,9 @@ CartridgeFA::CartridgeFA(const ByteBuffer& image, size_t size,
 bool CartridgeFA::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
-  if((address >= 0x0FF8) && (address <= 0x0FFA))
+  if((address >= 0x1FF8) && (address <= 0x1FFA))
   {
-    bank(address - 0x0FF8);
+    bank(address - 0x1FF8);
     return true;
   }
   return false;

src/emucore/CartFA2.cxx

@@ -42,9 +42,9 @@ CartridgeFA2::CartridgeFA2(const ByteBuffer& image, size_t size,
 bool CartridgeFA2::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
-  if((address >= 0x0FF5) && (address <= 0x0FFB))
+  if((address >= 0x1FF5) && (address <= 0x1FFB))
   {
-    bank(address - 0x0FF5);
+    bank(address - 0x1FF5);
     return true;
   }
   return false;

src/emucore/CartFC.cxx

@@ -37,7 +37,7 @@ void CartridgeFC::reset()
 bool CartridgeFC::checkSwitchBank(uInt16 address, uInt8)
 {
   // Switch banks if necessary
-  if(address == 0x0FFC)
+  if(address == 0x1FFC)
   {
     // Trigger the bank switch
     bank(myTargetBank);