Imported existing sources

nescorelib/mappers/mapper003.cpp

@@ -0,0 +1,17 @@
+#include "mapper003.h"
+
+QString Mapper003::name() const
+{
+    return QStringLiteral("CNROM");
+}
+
+quint8 Mapper003::mapper() const
+{
+    return 3;
+}
+
+void Mapper003::writePrg(quint16 address, quint8 value)
+{
+    // Bus conflicts !!
+    switch8kChr(readPrg(address) & value);
+}