Add mapper 468

src/boards/468_if12.h

@@ -0,0 +1,31 @@
+#define IF12_reg regByte
+
+static void IF12_sync () {
+	int AND =prgAND >>1;
+	int OR  =prgOR  >>1;
+	setprg16(0x8000, IF12_reg[1] &AND | OR &~AND);
+	setprg16(0xC000,        0xFF &AND | OR &~AND);
+	setchr8(IF12_reg[0] >>1 &0xF);
+	setmirror(IF12_reg[0] &1? MI_H: MI_V);
+}
+
+static DECLFW(IF12_writeReg) {
+	IF12_reg[A >>14 &1] =V;
+	sync();
+}
+
+void IF12_reset(uint8 clearRegs) {
+	sync =IF12_sync;
+	prgAND =mapperFlags &2? 0x0F: 0x1F;
+	SetWriteHandler(0x8000, 0xFFFF, IF12_writeReg);
+	sync();
+}
+
+void UNROM_IF12_reset(uint8 clearRegs) {
+	if (mapperFlags &8)
+		UNROM_reset(clearRegs);
+	else
+		IF12_reset(clearRegs);
+}
+
+#undef IF12_reg