Modified the autodetect routine to include a search for 3F style

bankswitching as suggested by Adam Wozniak.  This allows most of
the demos/homebrew games being created using this method to work
without a stella.pro file entry.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@164 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

stella/src/emucore/Cart.cxx

@@ -8,12 +8,12 @@
 //  SS  SS   tt   ee      ll   ll  aa  aa
 //   SSSS     ttt  eeeee llll llll  aaaaa
 //
-// Copyright (c) 1995-2002 by Bradford W. Mott
+// Copyright (c) 1995-2003 by Bradford W. Mott
 //
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart.cxx,v 1.5 2002-12-15 05:49:04 bwmott Exp $
+// $Id: Cart.cxx,v 1.6 2003-02-17 04:59:54 bwmott Exp $
 //============================================================================
 
 #include <assert.h>
@@ -178,7 +178,7 @@ string Cartridge::autodetectType(const uInt8* image, uInt32 size)
     }
     else if((size == 8192) || (memcmp(image, image + 8192, 8192) == 0))
     {
-      type = "F8";
+      type = isProbably3F(image, size) ? "3F" : "F8";
     }
     else if((size == 10495) || (size == 10240))
     {
@@ -199,18 +199,18 @@ string Cartridge::autodetectType(const uInt8* image, uInt32 size)
         if(image[i] != first)
         {
           // It's not a super cart (probably)
-          type = "F4";
+          type = isProbably3F(image, size) ? "3F" : "F4";
           break;
         }
       }
     }
     else if(size == 65536)
     {
-      type = "MB";
+      type = isProbably3F(image, size) ? "3F" : "MB";
     }
     else if(size == 131072)
     {
-      type = "MC";
+      type = isProbably3F(image, size) ? "3F" : "MC";
     }
     else
     {
@@ -223,7 +223,7 @@ string Cartridge::autodetectType(const uInt8* image, uInt32 size)
         if(image[i] != first)
         {
           // It's not a super cart (probably)
-          type = "F6";
+          type = isProbably3F(image, size) ? "3F" : "F6";
           break;
         }
       }
@@ -233,6 +233,21 @@ string Cartridge::autodetectType(const uInt8* image, uInt32 size)
   return type;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool Cartridge::isProbably3F(const uInt8* image, uInt32 size)
+{
+  uInt32 count = 0;
+  for(uInt32 i = 0; i < size - 1; ++i)
+  {
+    if((image[i] == 0x85) && (image[i + 1] == 0x3F))
+    {
+      ++count;
+    }
+  }
+
+  return (count > 2);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Cartridge::Cartridge(const Cartridge&)
 {

stella/src/emucore/Cart.hxx

@@ -8,12 +8,12 @@
 //  SS  SS   tt   ee      ll   ll  aa  aa
 //   SSSS     ttt  eeeee llll llll  aaaaa
 //
-// Copyright (c) 1995-1998 by Bradford W. Mott
+// Copyright (c) 1995-2003 by Bradford W. Mott
 //
 // See the file "license" for information on usage and redistribution of
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //
-// $Id: Cart.hxx,v 1.1.1.1 2001-12-27 19:54:18 bwmott Exp $
+// $Id: Cart.hxx,v 1.2 2003-02-17 04:59:54 bwmott Exp $
 //============================================================================
 
 #ifndef CARTRIDGE_HXX
@@ -31,7 +31,7 @@ class System;
   game and handles any bankswitching performed by the cartridge.
  
   @author  Bradford W. Mott
-  @version $Id: Cart.hxx,v 1.1.1.1 2001-12-27 19:54:18 bwmott Exp $
+  @version $Id: Cart.hxx,v 1.2 2003-02-17 04:59:54 bwmott Exp $
 */
 class Cartridge : public Device
 {
@@ -69,6 +69,11 @@ class Cartridge : public Device
     */
     static string autodetectType(const uInt8* image, uInt32 size);
 
+    /**
+      Returns true iff the image is probably a 3F bankswitching cartridge
+    */
+    static bool isProbably3F(const uInt8* image, uInt32 size);
+
   private:
     // Copy constructor isn't supported by cartridges so make it private
     Cartridge(const Cartridge&);