added WF8 detection and test ROMs

(cherry picked from commit 28050d5d9cfa502b4f0214c2b9e322a36dc0c4bf)

src/emucore/CartDetector.cxx

@@ -90,6 +90,8 @@ Bankswitch::Type CartDetector::autodetectType(const ByteBuffer& image, size_t si
       type = Bankswitch::Type::_FC;
     else if(isProbably03E0(image, size))
       type = Bankswitch::Type::_03E0;
+    else if (isProbablyWF8(image, size))
+      type = Bankswitch::Type::_WF8;
     else
       type = Bankswitch::Type::_F8;
   }
@@ -826,6 +828,20 @@ bool CartDetector::isProbablyWD(const ByteBuffer& image, size_t size)
   return searchForBytes(image, size, signature[0], 3);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool CartDetector::isProbablyWF8(const ByteBuffer& image, size_t size)
+{
+  // WF8 cart bankswitching for certain Coleco white lable ROMs, switches to 
+  // - bank 0 by writing D3 = 0  
+  // - bank 1 by writing D3 = 1
+  // into 0xfff8
+  static constexpr uInt8 sig[] = { 
+    0xa9, 0x04, 0x8d, 0xf8, 0xff 
+  };
+
+  return searchForBytes(image, size, sig, sizeof(sig));
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool CartDetector::isProbablyX07(const ByteBuffer& image, size_t size)
 {

src/emucore/CartDetector.hxx

@@ -241,6 +241,11 @@ class CartDetector
     */
     static bool isProbablyWD(const ByteBuffer& image, size_t size);
 
+    /**
+      Returns true if the image is probably a Coleco (white label) WF8 bankswitching cartridge
+    */
+    static bool isProbablyWF8(const ByteBuffer& image, size_t size);
+
     /**
       Returns true if the image is probably an X07 bankswitching cartridge
     */