--- /dev/null
+/* FCE Ultra - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ * Copyright (C) 2002 Xodnizel
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "mapinc.h"
+
+
+static void FP_FASTAPASS(1) Mapper50IRQ(int a)
+{
+ if(IRQa)
+ {
+ if(IRQCount<4096)
+ IRQCount+=a;
+ else
+ {
+ IRQa=0;
+ X6502_IRQBegin(FCEU_IQEXT);
+ }
+ }
+}
+
+static void M50Restore(int version)
+{
+ setprg8(0xc000,mapbyte1[0]);
+}
+
+static DECLFW(M50W)
+{
+ if((A&0xD060)==0x4020)
+ {
+ if(A&0x100)
+ {
+ IRQa=V&1;
+ if(!IRQa) IRQCount=0;
+ X6502_IRQEnd(FCEU_IQEXT);
+ }
+ else
+ {
+ V=((V&1)<<2)|((V&2)>>1)|((V&4)>>1)|(V&8);
+ mapbyte1[0]=V;
+ setprg8(0xc000,V);
+ }
+ }
+}
+
+void Mapper50_init(void)
+{
+ SetWriteHandler(0x4020,0x5fff,M50W);
+ SetReadHandler(0x6000,0xffff,CartBR);
+ MapStateRestore=M50Restore;
+ MapIRQHook=Mapper50IRQ;
+
+ setprg8(0x6000,0xF);
+ setprg8(0x8000,0x8);
+ setprg8(0xa000,0x9);
+ setprg8(0xc000,0x0);
+ setprg8(0xe000,0xB);
+}
+