First real pass at 4A50 support. It still doesn't compile yet, and may

not even work when it does :)


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@1393 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

stella/src/emucore/Cart4A50.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart4A50.cxx,v 1.6 2007-10-09 23:56:57 stephena Exp $
+// $Id: Cart4A50.cxx,v 1.7 2008-01-24 20:43:41 stephena Exp $
 //============================================================================
 
 #include <cassert>
@@ -47,178 +47,212 @@ Cartridge4A50::~Cartridge4A50()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Cartridge4A50::reset()
 {
-/*
+  mySliceLow = mySliceMiddle = mySliceHigh = 0;
-  // Setup segments to some default slices
+  myIsRomLow = myIsRomMiddle = myIsRomHigh = true;
-  segmentZero(4);
+
-  segmentOne(5);
+  myLastData    = 0xff;
-  segmentTwo(6);
+  myLastAddress = 0xffff;
-*/
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Cartridge4A50::install(System& system)
 {
-/*
   mySystem = &system;
   uInt16 shift = mySystem->pageShift();
   uInt16 mask = mySystem->pageMask();
 
   // Make sure the system we're being installed in has a page size that'll work
-  assert(((0x1000 & mask) == 0) && ((0x1400 & mask) == 0) &&
+  assert((0x1000 & mask) == 0);
-      ((0x1800 & mask) == 0) && ((0x1C00 & mask) == 0));
 
-  // Set the page acessing methods for the first part of the last segment
+  // Map all of the accesses to call peek and poke
   System::PageAccess access;
-  access.directPokeBase = 0;
+  for(uInt32 i = 0x1000; i < 0x2000; i += (1 << shift))
-  access.device = this;
-  for(uInt32 i = 0x1C00; i < (0x1FE0U & ~mask); i += (1 << shift))
   {
-    access.directPeekBase = &myImage[7168 + (i & 0x03FF)];
+    access.directPeekBase = 0;
+    access.directPokeBase = 0;
+    access.device = this;
     mySystem->setPageAccess(i >> shift, access);
   }
-  myCurrentSlice[3] = 7;
-
-  // Set the page accessing methods for the hot spots in the last segment
-  access.directPeekBase = 0;
-  access.directPokeBase = 0;
-  access.device = this;
-  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);
-  segmentOne(5);
-  segmentTwo(6);
-*/
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt8 Cartridge4A50::peek(uInt16 address)
 {
-/*
+  uInt8 value = 0;
-  address = address & 0x0FFF;
 
-  if(!bankLocked) {
+  if(!(address & 0x1000))
-    // Switch banks if necessary
+  {
-    if((address >= 0x0FE0) && (address <= 0x0FE7))
+    // ReadHardware();
+    bank(address);
+  }
+  else
+  {
+    if((address & 0x1800) == 0x1000)
     {
-      segmentZero(address & 0x0007);
+      value = myIsRomLow ?
+        myImage[(address & 0x7ff) + mySliceLow] : 
+        myRAM[(address & 0x7ff) + mySliceLow];
     }
-    else if((address >= 0x0FE8) && (address <= 0x0FEF))
+    else if(((address & 0x1fff) >= 0x1800) && ((address & 0x1fff) <= 0x1dff))
     {
-      segmentOne(address & 0x0007);
+      value = myIsRomMiddle ?
+        myImage[(address & 0x7ff) + mySliceMiddle] :
+        myRAM[(address & 0x7ff) + mySliceMiddle];
     }
-    else if((address >= 0x0FF0) && (address <= 0x0FF7))
+    else if((address & 0x1f00) == 0x1e00)
     {
-      segmentTwo(address & 0x0007);
+      value = myIsRomHigh ?
+        myImage[(address & 0xff) + mySliceHigh] :
+        myRAM[(address & 0xff) + mySliceHigh];
+    }
+    else if((address & 0x1f00) == 0x1f00)
+    {
+      value = myImage[(address & 0xff) + 0xff00];
+      if(((myLastData & 0xe0) == 0x60) &&
+         ((myLastAddress >= 0x1000) || (myLastAddress < 0x200)))
+        mySliceHigh = (mySliceHigh & 0xf0ff) | ((address & 0x8) << 8) |
+                      ((address & 0x70) << 4);
     }
   }
+  myLastData = value;
+  myLastAddress = address & 0x1fff;
 
-  return myImage[(myCurrentSlice[address >> 10] << 10) + (address & 0x03FF)];
+  return value;
-*/
-  return 0;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Cartridge4A50::poke(uInt16, uInt8)
+void Cartridge4A50::poke(uInt16 address, uInt8 value)
 {
-/*
+  if(!(address & 0x1000))
-  address = address & 0x0FFF;
+  {
-
+    // WriteHardware();
-  if(!bankLocked) {
+    bank(address);
-    // Switch banks if necessary
+  }
-    if((address >= 0x0FE0) && (address <= 0x0FE7))
+  else
+  {
+    if((address & 0x1800) == 0x1000)
     {
-      segmentZero(address & 0x0007);
+      if(!myIsRomLow)
+        myRAM[(address & 0x7ff) + mySliceLow] = value;
     }
-    else if((address >= 0x0FE8) && (address <= 0x0FEF))
+    else if(((address & 0x1fff) >= 0x1800) && ((address & 0x1fff) <= 0x1dff))
     {
-      segmentOne(address & 0x0007);
+      if(!myIsRomMiddle)
+        myRAM[(address & 0x7ff) + mySliceMiddle] = value;
     }
-    else if((address >= 0x0FF0) && (address <= 0x0FF7))
+    else if((address & 0x1f00) == 0x1e00)
     {
-      segmentTwo(address & 0x0007);
+      if(!myIsRomHigh)
+        myRAM[(address & 0xff) + mySliceHigh] = value;
+    }
+    else if((address & 0x1f00) == 0x1f00)
+    {
+      if(((myLastData & 0xe0) == 0x60) &&
+         ((myLastAddress >= 0x1000) || (myLastAddress < 0x200)))
+        mySliceHigh = (mySliceHigh & 0xf0ff) | ((address & 0x8) << 8) | ((address & 0x70) << 4);
     }
   }
-*/
+
+  myLastData = value;
+  myLastAddress = address & 0x1fff;
 } 
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Cartridge4A50::segmentZero(uInt16 slice)
+void Cartridge4A50::bank(uInt16 address)
-{ 
-/*
-  // Remember the new slice
-  myCurrentSlice[0] = slice;
-  uInt16 offset = slice << 10;
-  uInt16 shift = mySystem->pageShift();
-
-  // Setup the page access methods for the current bank
-  System::PageAccess access;
-  access.device = this;
-  access.directPokeBase = 0;
-
-  for(uInt32 address = 0x1000; address < 0x1400; address += (1 << shift))
-  {
-    access.directPeekBase = &myImage[offset + (address & 0x03FF)];
-    mySystem->setPageAccess(address >> shift, access);
-  }
-*/
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Cartridge4A50::segmentOne(uInt16 slice)
-{ 
-/*
-  // Remember the new slice
-  myCurrentSlice[1] = slice;
-  uInt16 offset = slice << 10;
-  uInt16 shift = mySystem->pageShift();
-
-  // Setup the page access methods for the current bank
-  System::PageAccess access;
-  access.device = this;
-  access.directPokeBase = 0;
-
-  for(uInt32 address = 0x1400; address < 0x1800; address += (1 << shift))
-  {
-    access.directPeekBase = &myImage[offset + (address & 0x03FF)];
-    mySystem->setPageAccess(address >> shift, access);
-  }
-*/
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Cartridge4A50::segmentTwo(uInt16 slice)
-{ 
-/*
-  // Remember the new slice
-  myCurrentSlice[2] = slice;
-  uInt16 offset = slice << 10;
-  uInt16 shift = mySystem->pageShift();
-
-  // Setup the page access methods for the current bank
-  System::PageAccess access;
-  access.device = this;
-  access.directPokeBase = 0;
-
-  for(uInt32 address = 0x1800; address < 0x1C00; address += (1 << shift))
-  {
-    access.directPeekBase = &myImage[offset + (address & 0x03FF)];
-    mySystem->setPageAccess(address >> shift, access);
-  }
-*/
-}
-
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Cartridge4A50::bank(uInt16 b)
 {
+  // Not bankswitching in the normal sense
+  // This scheme contains so many hotspots that it's easier to just check
+  // all of them
+  if(((myLastData & 0xe0) == 0x60) &&
+     ((myLastAddress >= 0x1000) || (myLastAddress < 0x200)))
+  {
+    if((address & 0x0f00) == 0x0c00)
+    {
+      myIsRomHigh = true;
+      mySliceHigh = (address & 0xff) << 8;
+    }
+    else if((address & 0x0f00) == 0x0d00)
+    {
+      myIsRomHigh = false;
+      mySliceHigh = (address & 0x7f) << 8;
+    }
+    else if((address & 0x0f40) == 0x0e00)
+    {
+      myIsRomLow = true;
+      mySliceLow = (address & 0x1f) << 11;
+    }
+    else if((address & 0x0f40) == 0x0e40)
+    {
+      myIsRomLow = false;
+      mySliceLow = (address & 0xf) << 11;
+    }
+    else if((address & 0x0f40) == 0x0f00)
+    {
+      myIsRomMiddle = true;
+      mySliceMiddle = (address & 0x1f) << 11;
+    }
+    else if((address & 0x0f50) == 0x0f40)
+    {
+      myIsRomMiddle = false;
+      mySliceMiddle = (address & 0xf) << 11;
+    }
+    else if((address & 0x0f00) == 0x0400)
+    {
+      mySliceLow = mySliceLow ^ 0x800;
+    }
+    else if((address & 0x0f00) == 0x0500)
+    {
+      mySliceLow = mySliceLow ^ 0x1000;
+    }
+    else if((address & 0x0f00) == 0x0800)
+    {
+      mySliceMiddle = mySliceMiddle ^ 0x800;
+    }
+    else if((address & 0x0f00) == 0x0900)
+    {
+      mySliceMiddle = mySliceMiddle ^ 0x1000;
+    }
+  }
+
+  if((address & 0xf75) == 0x74)
+  {
+    myIsRomHigh = true;
+    mySliceHigh = value << 8;
+  }
+  else if((address & 0xf75) == 0x75)
+  {
+    myIsRomHigh = false;
+    mySliceHigh = (value & 0x7f) << 8;
+  }
+  else if((address & 0xf7c) == 0x78)
+  {
+    if((value & 0xf0) == 0)
+    {
+      myIsRomLow = true;
+      mySliceLow = (value & 0xf) << 11;            
+    }
+    else if((value & 0xf0) == 0x40)
+    {
+      myIsRomLow = false;
+      mySliceLow = (value & 0xf) << 11;            
+    }
+    else if((value & 0xf0) == 0x90)
+    {
+      myIsRomMiddle = true;
+      mySliceMiddle = ((value & 0xf) | 0x10) << 11;                            
+    }
+    else if((value & 0xf0) == 0xc0)
+    {
+      myIsRomMiddle = false;
+      mySliceMiddle = (value & 0xf) << 11;                         
+    }
+  }
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 int Cartridge4A50::bank()
 {
+  // Doesn't support bankswitching in the normal sense
   return 0;
 }
 

stella/src/emucore/Cart4A50.hxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart4A50.hxx,v 1.7 2007-10-09 23:56:57 stephena Exp $
+// $Id: Cart4A50.hxx,v 1.8 2008-01-24 20:43:41 stephena Exp $
 //============================================================================
 
 #ifndef CARTRIDGE4A50_HXX
@@ -37,7 +37,7 @@ class System;
   bytes of ROM.
 
   @author  Stephen Anthony
-  @version $Id: Cart4A50.hxx,v 1.7 2007-10-09 23:56:57 stephena Exp $
+  @version $Id: Cart4A50.hxx,v 1.8 2008-01-24 20:43:41 stephena Exp $
 */
 class Cartridge4A50 : public Cartridge
 {
@@ -144,36 +144,25 @@ class Cartridge4A50 : public Cartridge
     virtual void poke(uInt16 address, uInt8 value);
 
   private:
-    /**
-      Install the specified slice for segment zero
-
-      @param slice The slice to map into the segment
-    */
-    void segmentZero(uInt16 slice);
-
-    /**
-      Install the specified slice for segment one
-
-      @param slice The slice to map into the segment
-    */
-    void segmentOne(uInt16 slice);
-
-    /**
-      Install the specified slice for segment two
-
-      @param slice The slice to map into the segment
-    */
-    void segmentTwo(uInt16 slice);
-
-  private:
-    // Indicates the slice mapped into each of the four segments
-    uInt16 myCurrentSlice[4];
-
     // The 64K ROM image of the cartridge
     uInt8 myImage[65536];
 
     // The 32K of RAM on the cartridge
     uInt8 myRAM[32768];
+
+    // Indicates the slice mapped into each of the three segments
+    uInt16 mySliceLow;     /* index pointer for $1000-$17ff slice */
+    uInt16 mySliceMiddle;  /* index pointer for $1800-$1dff slice */
+    uInt16 mySliceHigh;    /* index pointer for $1e00-$1eff slice */
+
+    // Indicates whether the given slice is mapped to ROM or RAM
+    bool myIsRomLow;       /* true = ROM -- false = RAM at $1000-$17ff */
+    bool myIsRomMiddle;    /* true = ROM -- false = RAM at $1800-$1dff */
+    bool myIsRomHigh;      /* true = ROM -- false = RAM at $1e00-$1eFF */
+
+    // The previous address and data values (from peek and poke)
+    uInt16 myLastAddress;
+    uInt8 myLastData;
 };
 
 #endif

stella/src/emucore/OSystem.cxx

@@ -13,7 +13,7 @@
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: OSystem.cxx,v 1.112 2007-10-09 23:56:57 stephena Exp $
+// $Id: OSystem.cxx,v 1.113 2008-01-24 20:43:41 stephena Exp $
 //============================================================================
 
 #include <cassert>
@@ -769,8 +769,8 @@ void OSystem::queryVideoHardware()
 
   // First get the maximum windowed desktop resolution
   const SDL_VideoInfo* info = SDL_GetVideoInfo();
-  myDesktopWidth  = info->current_w;
+  myDesktopWidth  = 1024;//info->current_w;
-  myDesktopHeight = info->current_h;
+  myDesktopHeight = 768;//info->current_h;
 
   // Then get the valid fullscreen modes
   // If there are any errors, just use the desktop resolution