improved bank origin detection (fixes #428)

src/debugger/CartDebug.cxx

@@ -290,7 +290,7 @@ bool CartDebug::disassemble(int bank, uInt16 PC, bool force)
     // If the offset has changed, all old addresses must be 'converted'
     // For example, if the list contains any $fxxx and the address space is now
     // $bxxx, it must be changed
-    uInt16 offset = (PC - (PC % 0x1000));
+    uInt16 offset = myConsole.cartridge().bankOrigin(bank, PC);
     AddressList& addresses = info.addressList;
     for(auto& i: addresses)
       i = (i & 0xFFF) + offset;

src/emucore/Cart.cxx

@@ -180,10 +180,10 @@ string Cartridge::getAccessCounters() const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt16 Cartridge::bankOrigin(uInt16 bank) const
+uInt16 Cartridge::bankOrigin(uInt16 bank, uInt16 PC) const
 {
-  // isolate the high 3 address bits, count them and
-  // select the most frequent to define the bank origin
+  // Isolate the high 3 address bits, count them, include the PC if provided
+  // and select the most frequent to define the bank origin
   // TODO: origin for banks smaller than 4K
   constexpr int intervals = 0x8000 / 0x100;
   const uInt32 offset = bank * bankSize();
@@ -196,6 +196,8 @@ uInt16 Cartridge::bankOrigin(uInt16 bank) const
   //addrMask;
 
   count.fill(0);
+  if(PC)
+    count[PC >> 13]++;
   for(uInt16 addr = 0x0000; addr < bankSize(bank); ++addr)
   {
     const Device::AccessFlags flags = myRomAccessBase[offset + addr];

src/emucore/Cart.hxx

@@ -189,9 +189,10 @@ class Cartridge : public Device
       Determine the bank's origin
 
       @param bank  The bank to query
+      @param PC    The current PC
       @return  The origin of the bank
     */
-    uInt16 bankOrigin(uInt16 bank) const;
+    uInt16 bankOrigin(uInt16 bank, uInt16 PC = 0) const;
   #endif
 
   public: