Add mapper 468

src/boards/468_discrete.h

@@ -0,0 +1,74 @@
+#define latch regByte[0]
+
+static void ANROM_sync () {
+	int AND =prgAND >>2;
+	int OR  =prgOR  >>2;
+	setprg32(0x8000, latch &AND | OR &~AND);
+	setchr8(0);
+	setmirror(latch &0x10? MI_1: MI_0);
+}
+
+static void BNROM_sync () {
+	int AND =prgAND >>2;
+	int OR  =prgOR  >>2;
+	setprg32(0x8000, latch &AND | OR &~AND);
+	setchr8(0);
+	setmirror(mapperFlags &4? MI_H: MI_V);
+}
+
+static void GNROM_sync () {
+	int AND =prgAND >>2;
+	int OR  =prgOR  >>2 | (mapperFlags &4? 2: 0);
+	setprg32(0x8000, latch >>4 &AND | OR &~AND);
+	setchr8(latch &0x0F);
+	setmirror(mapper &1? MI_H: MI_V);
+}
+
+static void UNROM_sync () {
+	int AND =prgAND >>1;
+	int OR  =prgOR  >>1;
+	setprg16(0x8000, latch &AND | OR &~AND);
+	setprg16(0xC000,  0xFF &AND | OR &~AND);
+	setchr8(0);
+	setmirror(mapperFlags &4? MI_H: MI_V);
+}
+
+static DECLFW(DISCRETE_writeLatch) {
+	if (mapper ==0x09 && mapperFlags ==0xE && A ==0xA000 && V ==0x00)
+		V =0x06; // UNROM: Strange hack, needed to get #282 "Portopia Serial Murder Case" on 852-in-1 running
+	latch =V;
+	sync();
+}
+
+static DECLFW(GNROM_writeLatch) {
+	if (~prgOR &0x2000 || mapper ==0x1C || mapper==0x1D)
+		V =V >>4 &0xF | V <<4 &0xF0; // Color Dreams: swap nibbles to mimic GNROM
+	latch =V;
+	sync();
+}
+
+
+void ANROM_BNROM_reset(uint8 clearRegs) {
+	sync =mapperFlags &8? BNROM_sync: ANROM_sync;
+	prgAND =(mapper ==0x06 || mapper ==0x16)? 0x3F: mapperFlags &2? 0x0F: 0x1F;
+	SetWriteHandler(0x8000, 0xFFFF, DISCRETE_writeLatch);
+	latch =0;
+	sync();
+}
+
+void GNROM_reset(uint8 clearRegs) {
+	sync =GNROM_sync;
+	prgAND =mapperFlags &8? 0x07: 0x0F;
+	SetWriteHandler(0x8000, 0xFFFF, GNROM_writeLatch);
+	latch =0;
+	sync();
+}
+
+void UNROM_reset(uint8 clearRegs) {
+	sync =UNROM_sync;
+	prgAND =mapper ==0x0B || mapper ==0x17 &&~mapperFlags &8? 0x3F: mapperFlags &2? 0x0F: 0x1F;
+	SetWriteHandler(0x8000, 0xFFFF, DISCRETE_writeLatch);
+	sync();
+}
+
+#undef latch