Added 'PageType' infrastructure to PageAccess, which basically

informs the rest of the system about how a page of address
space is to be treated (READ, WRITE, READWRITE).  This makes it
much easier to track if a read from the write port has occurred.
As such, the _rwport command should now be somewhat faster.
Eventually, the debugger/disassembler will use this info to
colorize the output.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@2004 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

src/debugger/CartDebug.cxx

@@ -33,7 +33,6 @@ CartDebug::CartDebug(Debugger& dbg, Console& console, const RamAreaList& areas)
   addRamArea(0x80, 128, 0, 0);
 
   // Add extended RAM
-  myRamAreas = areas;
   for(RamAreaList::const_iterator i = areas.begin(); i != areas.end(); ++i)
     addRamArea(i->start, i->size, i->roffset, i->woffset);
 
@@ -125,25 +124,18 @@ void CartDebug::triggerReadFromWritePort(uInt16 addr)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 int CartDebug::readFromWritePort()
 {
-  uInt16 peekAddress = myRWPortAddress;
+  uInt16 addr = myRWPortAddress;
   myRWPortAddress = 0;
 
   // A read from the write port occurs when the read is actually in the write
   // port address space AND the last access was actually a read (the latter
   // differentiates between reads that are normally part of a write cycle vs.
   // ones that are illegal)
-  if(mySystem.m6502().lastReadAddress() && peekAddress & 0x1000)
+  if(mySystem.m6502().lastReadAddress() &&
-  {
+      (mySystem.getPageType(addr) & System::PAGE_WRITE) == System::PAGE_WRITE)
-    uInt16 addr = peekAddress & 0x0FFF;
+    return addr;
-    for(RamAreaList::const_iterator i = myRamAreas.begin(); i != myRamAreas.end(); ++i)
+  else
-    {
+    return 0;
-      uInt16 start = (i->start + i->woffset) & 0x0FFF;
-      uInt16 end = (i->start + i->woffset + i->size) & 0x0FFF;
-      if(addr >= start && addr < end)
-        return peekAddress;
-    }
-  }
-  return 0;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/debugger/CartDebug.hxx

@@ -213,8 +213,6 @@ class CartDebug : public DebuggerSystem
     CartState myState;
     CartState myOldState;
 
-    RamAreaList myRamAreas;
-
     // A pointer to an array of start addresses for each bank in a cart
     // The startup bank will normally be 0xfffc, while the others are
     // determined when the debugger is first opened

src/debugger/Debugger.cxx

@@ -674,6 +674,7 @@ GUI::Rect Debugger::getTabBounds() const
 bool Debugger::addFunction(const string& name, const string& definition,
                            Expression* exp, bool builtin)
 {
+cerr << "adding function: " << name << endl;
   functions.insert(make_pair(name, exp));
   if(!builtin)
     functionDefs.insert(make_pair(name, definition));
@@ -762,6 +763,10 @@ void Debugger::getCompletions(const char* in, StringList& list) const
     if(BSPF_strncasecmp(l, in, strlen(in)) == 0)
       list.push_back(l);
   }
+
+
+for(uInt32 i = 0; i < list.size(); ++i)
+cerr << list[i] << endl;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/Cart0840.cxx

@@ -68,13 +68,13 @@ void Cartridge0840::install(System& system)
 
   // Set the page accessing methods for the hot spots
   System::PageAccess access;
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
+
   for(uInt32 i = 0x0800; i < 0x0FFF; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for bank 0
   bank(myStartBank);
@@ -157,8 +157,9 @@ void Cartridge0840::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))

src/emucore/Cart2K.cxx

@@ -76,11 +76,13 @@ void Cartridge2K::install(System& system)
 
   // Map ROM image into the system
   System::PageAccess access;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
+
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myImage[address & myMask];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(address >> shift, access);
   }
 }

src/emucore/Cart3E.cxx

@@ -70,25 +70,26 @@ void Cartridge3E::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1800 & mask) == 0);
 
+  System::PageAccess access;
+
   // Set the page accessing methods for the hot spots (for 100% emulation
   // we need to chain any accesses below 0x40 to the TIA. Our poke() method
   // does this via mySystem->tiaPoke(...), at least until we come up with a
   // cleaner way to do it).
-  System::PageAccess access;
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READWRITE;
   for(uInt32 i = 0x00; i < 0x40; i += (1 << shift))
-  {
-    access.device = this;
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Setup the second segment to always point to the last ROM slice
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 j = 0x1800; j < 0x2000; j += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myImage[(mySize - 2048) + (j & 0x07FF)];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(j >> shift, access);
   }
 
@@ -180,8 +181,9 @@ void Cartridge3E::bank(uInt16 bank)
   
     // Setup the page access methods for the current bank
     System::PageAccess access;
-    access.device = this;
     access.directPokeBase = 0;
+    access.device = this;
+    access.type = System::PAGE_READ;
 
     // Map ROM image into the system
     for(uInt32 address = 0x1000; address < 0x1800; address += (1 << shift))
@@ -202,8 +204,9 @@ void Cartridge3E::bank(uInt16 bank)
   
     // Setup the page access methods for the current bank
     System::PageAccess access;
-    access.device = this;
     access.directPokeBase = 0;
+    access.device = this;
+    access.type = System::PAGE_READ;
 
     // Map read-port RAM image into the system
     for(address = 0x1000; address < 0x1400; address += (1 << shift))
@@ -213,6 +216,7 @@ void Cartridge3E::bank(uInt16 bank)
     }
 
     access.directPeekBase = 0;
+    access.type = System::PAGE_WRITE;
 
     // Map write-port RAM image into the system
     for(address = 0x1400; address < 0x1800; address += (1 << shift))

src/emucore/Cart3F.cxx

@@ -66,20 +66,20 @@ void Cartridge3F::install(System& system)
   // does this via mySystem->tiaPoke(...), at least until we come up with a
   // cleaner way to do it).
   System::PageAccess access;
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READWRITE;
   for(uInt32 i = 0x00; i < 0x40; i += (1 << shift))
-  {
-    access.device = this;
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Setup the second segment to always point to the last ROM slice
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 j = 0x1800; j < 0x2000; j += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myImage[(mySize - 2048) + (j & 0x07FF)];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(j >> shift, access);
   }
 
@@ -144,8 +144,9 @@ void Cartridge3F::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x1800; address += (1 << shift))

src/emucore/Cart4A50.cxx

@@ -73,6 +73,8 @@ void Cartridge4A50::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;  // We don't yet indicate RAM areas
+
   for(uInt32 i = 0x1000; i < 0x2000; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
 

src/emucore/Cart4K.cxx

@@ -54,6 +54,7 @@ void Cartridge4K::install(System& system)
   System::PageAccess access;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))

src/emucore/CartAR.cxx

@@ -98,6 +98,8 @@ void CartridgeAR::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;  // We don't yet indicate RAM areas
+
   for(uInt32 i = 0x1000; i < 0x2000; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
 

src/emucore/CartCV.cxx

@@ -87,29 +87,32 @@ void CartridgeCV::install(System& system)
   System::PageAccess access;
 
   // Map ROM image into the system
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 address = 0x1800; address < 0x2000; address += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myImage[address & 0x07FF];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(address >> mySystem->pageShift(), access);
   }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1400; j < 0x1800; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x03FF];
     mySystem->setPageAccess(j >> shift, access);
   }
 
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1000; k < 0x1400; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x03FF];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 }

src/emucore/CartDPC.cxx

@@ -88,24 +88,23 @@ void CartridgeDPC::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert(((0x1080 & mask) == 0) && ((0x1100 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF8 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the DPC reading & writing pages
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READWRITE;
   for(uInt32 j = 0x1000; j < 0x1080; j += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(j >> shift, access);
-  }
 
   // Install pages for the startup bank
   bank(myStartBank);
@@ -430,8 +429,9 @@ void CartridgeDPC::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map Program ROM image into the system
   for(uInt32 address = 0x1080; address < (0x1FF8U & ~mask);

src/emucore/CartDPCPlus.cxx

@@ -100,6 +100,7 @@ void CartridgeDPCPlus::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = 0x1000; i < 0x2000; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
   

src/emucore/CartE0.cxx

@@ -57,10 +57,12 @@ void CartridgeE0::install(System& system)
   assert(((0x1000 & mask) == 0) && ((0x1400 & mask) == 0) &&
       ((0x1800 & mask) == 0) && ((0x1C00 & mask) == 0));
 
-  // Set the page acessing methods for the first part of the last segment
   System::PageAccess access;
+
+  // Set the page acessing methods for the first part of the last segment
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = 0x1C00; i < (0x1FE0U & ~mask); i += (1 << shift))
   {
     access.directPeekBase = &myImage[7168 + (i & 0x03FF)];
@@ -72,10 +74,9 @@ void CartridgeE0::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 j = (0x1FE0 & ~mask); j < 0x2000; j += (1 << shift))
-  {
     mySystem->setPageAccess(j >> shift, access);
-  }
 
   // Install some default slices for the other segments
   segmentZero(4);
@@ -138,8 +139,9 @@ void CartridgeE0::segmentZero(uInt16 slice)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   for(uInt32 address = 0x1000; address < 0x1400; address += (1 << shift))
   {
@@ -161,8 +163,9 @@ void CartridgeE0::segmentOne(uInt16 slice)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   for(uInt32 address = 0x1400; address < 0x1800; address += (1 << shift))
   {
@@ -184,8 +187,9 @@ void CartridgeE0::segmentTwo(uInt16 slice)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   for(uInt32 address = 0x1800; address < 0x1C00; address += (1 << shift))
   {

src/emucore/CartE7.cxx

@@ -70,22 +70,23 @@ void CartridgeE7::install(System& system)
   assert(((0x1400 & mask) == 0) && ((0x1800 & mask) == 0) &&
       ((0x1900 & mask) == 0) && ((0x1A00 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FE0 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Setup the second segment to always point to the last ROM slice
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 j = 0x1A00; j < (0x1FE0U & ~mask); j += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myImage[7 * 2048 + (j & 0x07FF)];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(j >> shift, access);
   }
   myCurrentSlice[1] = 7;
@@ -176,21 +177,22 @@ void CartridgeE7::bankRAM(uInt16 bank)
   System::PageAccess access;
 
   // Set the page accessing method for the 256 bytes of RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1800; j < 0x1900; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[1024 + offset + (j & 0x00FF)];
     mySystem->setPageAccess(j >> shift, access);
   }
 
   // Set the page accessing method for the 256 bytes of RAM reading pages
-  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1900; k < 0x1A00; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[1024 + offset + (k & 0x00FF)];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
   myBankChanged = true;
@@ -212,31 +214,34 @@ void CartridgeE7::bank(uInt16 slice)
   if(slice != 7)
   {
     // Map ROM image into first segment
+    access.directPokeBase = 0;
+    access.device = this;
+    access.type = System::PAGE_READ;
     for(uInt32 address = 0x1000; address < 0x1800; address += (1 << shift))
     {
-      access.device = this;
       access.directPeekBase = &myImage[offset + (address & 0x07FF)];
-      access.directPokeBase = 0;
       mySystem->setPageAccess(address >> shift, access);
     }
   }
   else
   {
     // Set the page accessing method for the 1K slice of RAM writing pages
+    access.directPeekBase = 0;
+    access.device = this;
+    access.type = System::PAGE_WRITE;
     for(uInt32 j = 0x1000; j < 0x1400; j += (1 << shift))
     {
-      access.device = this;
-      access.directPeekBase = 0;
       access.directPokeBase = &myRAM[j & 0x03FF];
       mySystem->setPageAccess(j >> shift, access);
     }
 
     // Set the page accessing method for the 1K slice of RAM reading pages
+    access.directPokeBase = 0;
+    access.device = this;
+    access.type = System::PAGE_READ;
     for(uInt32 k = 0x1400; k < 0x1800; k += (1 << shift))
     {
-      access.device = this;
       access.directPeekBase = &myRAM[k & 0x03FF];
-      access.directPokeBase = 0;
       mySystem->setPageAccess(k >> shift, access);
     }
   }

src/emucore/CartEF.cxx

@@ -55,15 +55,15 @@ void CartridgeEF::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FE0 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for the startup bank
   bank(myStartBank);
@@ -104,10 +104,12 @@ void CartridgeEF::bank(uInt16 bank)
   uInt16 shift = mySystem->pageShift();
   uInt16 mask = mySystem->pageMask();
 
-  // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
+
+  // Setup the page access methods for the current bank
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < (0x1FE0U & ~mask);

src/emucore/CartEFSC.cxx

@@ -62,31 +62,33 @@ void CartridgeEFSC::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FE0 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1000; j < 0x1080; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x007F];
     mySystem->setPageAccess(j >> shift, access);
   }
  
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1080; k < 0x1100; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x007F];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 
@@ -149,8 +151,9 @@ void CartridgeEFSC::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1100; address < (0x1FE0U & ~mask);

src/emucore/CartF0.cxx

@@ -56,15 +56,15 @@ void CartridgeF0::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF0 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for bank 1
   myCurrentBank = 0;
@@ -109,8 +109,9 @@ void CartridgeF0::incbank()
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < (0x1FF0U & ~mask);

src/emucore/CartF4.cxx

@@ -56,15 +56,15 @@ void CartridgeF4::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF4 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for the startup bank
   bank(myStartBank);
@@ -111,8 +111,9 @@ void CartridgeF4::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < (0x1FF4U & ~mask);

src/emucore/CartF4SC.cxx

@@ -62,31 +62,33 @@ void CartridgeF4SC::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert(((0x1080 & mask) == 0) && ((0x1100 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF4 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1000; j < 0x1080; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x007F];
     mySystem->setPageAccess(j >> shift, access);
   }
 
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1080; k < 0x1100; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x007F];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 
@@ -152,8 +154,9 @@ void CartridgeF4SC::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1100; address < (0x1FF4U & ~mask);

src/emucore/CartF6.cxx

@@ -55,15 +55,15 @@ void CartridgeF6::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF6 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Upon install we'll setup the startup bank
   bank(myStartBank);
@@ -151,8 +151,9 @@ void CartridgeF6::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < (0x1FF6U & ~mask);

src/emucore/CartF6SC.cxx

@@ -62,31 +62,33 @@ void CartridgeF6SC::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert(((0x1080 & mask) == 0) && ((0x1100 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF6 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1000; j < 0x1080; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x007F];
     mySystem->setPageAccess(j >> shift, access);
   }
 
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1080; k < 0x1100; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x007F];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 
@@ -195,8 +197,9 @@ void CartridgeF6SC::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1100; address < (0x1FF6U & ~mask);

src/emucore/CartF8.cxx

@@ -56,15 +56,15 @@ void CartridgeF8::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert((0x1000 & mask) == 0);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF8 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for the startup bank
   bank(myStartBank);
@@ -132,8 +132,9 @@ void CartridgeF8::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < (0x1FF8U & ~mask);

src/emucore/CartF8SC.cxx

@@ -62,31 +62,33 @@ void CartridgeF8SC::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert(((0x1080 & mask) == 0) && ((0x1100 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF8 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1000; j < 0x1080; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x007F];
     mySystem->setPageAccess(j >> shift, access);
   }
  
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1080; k < 0x1100; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x007F];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 
@@ -175,8 +177,9 @@ void CartridgeF8SC::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1100; address < (0x1FF8U & ~mask);

src/emucore/CartFA.cxx

@@ -62,31 +62,33 @@ void CartridgeFA::install(System& system)
   // Make sure the system we're being installed in has a page size that'll work
   assert(((0x1100 & mask) == 0) && ((0x1200 & mask) == 0));
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = (0x1FF8 & ~mask); i < 0x2000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Set the page accessing method for the RAM writing pages
+  access.directPeekBase = 0;
+  access.device = this;
+  access.type = System::PAGE_WRITE;
   for(uInt32 j = 0x1000; j < 0x1100; j += (1 << shift))
   {
-    access.device = this;
-    access.directPeekBase = 0;
     access.directPokeBase = &myRAM[j & 0x00FF];
     mySystem->setPageAccess(j >> shift, access);
   }
  
   // Set the page accessing method for the RAM reading pages
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 k = 0x1100; k < 0x1200; k += (1 << shift))
   {
-    access.device = this;
     access.directPeekBase = &myRAM[k & 0x00FF];
-    access.directPokeBase = 0;
     mySystem->setPageAccess(k >> shift, access);
   }
 
@@ -185,8 +187,9 @@ void CartridgeFA::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1200; address < (0x1FF8U & ~mask);

src/emucore/CartFE.cxx

@@ -58,6 +58,7 @@ void CartridgeFE::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = 0x1000; i < 0x2000; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
 }

src/emucore/CartMC.cxx

@@ -80,10 +80,15 @@ void CartridgeMC::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READWRITE;
   for(uInt32 i = 0x00; i < 0x40; i += (1 << shift))
     mySystem->setPageAccess(i >> shift, access);
 
   // Map the cartridge into the system
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;  // We don't yet indicate RAM areas
   for(uInt32 j = 0x1000; j < 0x2000; j += (1 << shift))
     mySystem->setPageAccess(j >> shift, access);
 }

src/emucore/CartSB.cxx

@@ -71,15 +71,15 @@ void CartridgeSB::install(System& system)
   myHotSpotPageAccess[6] = mySystem->getPageAccess(0x0E00 >> shift);
   myHotSpotPageAccess[7] = mySystem->getPageAccess(0x0F00 >> shift);
 
-  // Set the page accessing methods for the hot spots
   System::PageAccess access;
+
+  // Set the page accessing methods for the hot spots
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
   for(uInt32 i = 0x0800; i < 0x0FFF; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for startup bank
   bank(myStartBank);
@@ -136,8 +136,9 @@ void CartridgeSB::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))

src/emucore/CartUA.cxx

@@ -64,6 +64,7 @@ void CartridgeUA::install(System& system)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = this;
+  access.type = System::PAGE_READ;
   mySystem->setPageAccess(0x0220 >> shift, access);
   mySystem->setPageAccess(0x0240 >> shift, access);
 
@@ -144,8 +145,9 @@ void CartridgeUA::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))

src/emucore/CartX07.cxx

@@ -61,13 +61,12 @@ void CartridgeX07::install(System& system)
   // The hotspots use almost all addresses below 0x1000, so we simply grab them
   // all and forward the TIA/RIOT calls from the peek and poke methods.
   System::PageAccess access;
+  access.directPeekBase = 0;
+  access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READWRITE;
   for(uInt32 i = 0x00; i < 0x1000; i += (1 << shift))
-  {
-    access.directPeekBase = 0;
-    access.directPokeBase = 0;
-    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
-  }
 
   // Install pages for the startup bank
   bank(myStartBank);
@@ -130,8 +129,9 @@ void CartridgeX07::bank(uInt16 bank)
 
   // Setup the page access methods for the current bank
   System::PageAccess access;
-  access.device = this;
   access.directPokeBase = 0;
+  access.device = this;
+  access.type = System::PAGE_READ;
 
   // Map ROM image into the system
   for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))

src/emucore/M6532.cxx

@@ -91,18 +91,15 @@ void M6532::install(System& system, Device& device)
   
   // All accesses are to the given device
   System::PageAccess access;
+  access.directPeekBase = 0; 
+  access.directPokeBase = 0;
   access.device = &device;
+  access.type = System::PAGE_READWRITE;
 
   // We're installing in a 2600 system
   for(int address = 0; address < 8192; address += (1 << shift))
-  {
     if((address & 0x1080) == 0x0080)
-    {
-      access.directPeekBase = 0; 
-      access.directPokeBase = 0;
       mySystem->setPageAccess(address >> shift, access);
-    }
-  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/System.cxx

@@ -179,6 +179,12 @@ const System::PageAccess& System::getPageAccess(uInt16 page) const
   return myPageAccessTable[page];
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+System::PageType System::getPageType(uInt16 addr) const
+{
+  return myPageAccessTable[(addr & myAddressMask) >> myPageShift].type;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void System::setDirtyPage(uInt16 addr)
 {

src/emucore/System.hxx

@@ -287,6 +287,12 @@ class System : public Serializable
     void unlockDataBus();
 
   public:
+    enum PageType {
+      PAGE_READ      = 1 << 0,
+      PAGE_WRITE     = 1 << 1,
+      PAGE_READWRITE = PAGE_READ | PAGE_WRITE
+    };
+
     /**
       Structure used to specify access methods for a page
     */
@@ -310,9 +316,15 @@ class System : public Serializable
 
       /**
         Pointer to the device associated with this page or to the system's 
-        null device if the page hasn't been mapped to a device
+        null device if the page hasn't been mapped to a device.
       */
       Device* device;
+
+      /**
+        The manner in which the pages are accessed by the system
+        (READ, WRITE, READ|WRITE)
+      */
+      PageType type;
     };
 
     /**
@@ -331,6 +343,14 @@ class System : public Serializable
     */
     const PageAccess& getPageAccess(uInt16 page) const;
  
+    /**
+      Get the page type for the given address.
+
+      @param addr  The address contained in the page in questions
+      @return  The type of page that contains the given address
+    */
+    PageType getPageType(uInt16 addr) const;
+
     /**
       Mark the page containing this address as being dirty.
 

src/emucore/TIA.cxx

@@ -295,15 +295,12 @@ void TIA::install(System& system, Device& device)
   access.directPeekBase = 0;
   access.directPokeBase = 0;
   access.device = &device;
+  access.type = System::PAGE_READWRITE;
 
   // We're installing in a 2600 system
   for(uInt32 i = 0; i < 8192; i += (1 << shift))
-  {
     if((i & 0x1080) == 0x0000)
-    {
       mySystem->setPageAccess(i >> shift, access);
-    }
-  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -