From e6d6c874dbf6464d717e4a49310833639f32376e Mon Sep 17 00:00:00 2001
From: NewRisingSun <8vytz1+dhp372pv94ebg@sharklasers.com>
Date: Tue, 9 Sep 2025 21:43:07 +0200
Subject: [PATCH] Add mapper 512.

---
 src/boards/512.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/ines.c       |  1 +
 src/ines.h       |  1 +
 3 files changed, 87 insertions(+)
 create mode 100644 src/boards/512.c

diff --git a/src/boards/512.c b/src/boards/512.c
new file mode 100644
index 0000000..0645355
--- /dev/null
+++ b/src/boards/512.c
@@ -0,0 +1,85 @@
+/* FCEUmm - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ *  Copyright (C) 2020
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ *
+ */
+
+#include "mapinc.h"
+#include "asic_mmc3.h"
+#include "wram.h"
+
+static uint8 reg;
+static uint8 *CHRRAM = NULL;
+
+static void sync () {
+	MMC3_syncPRG(0x3F, 0x00);
+	MMC3_syncWRAM(0);
+	
+	if (reg &0x02) {
+		setchr4r(0x10, 0x0000, 0);
+		setchr4r(0x10, 0x1000, 0);
+	} else
+		MMC3_syncCHR(0xFF, 0x000);
+	
+	if (reg == 1) { /* The game uses six nametables - the two console-internal ones, plus four occupying the second half of 8 KiB CHR-RAM.*/
+		setntamem(CHRptr[0x10] +0x1000, 1, 0);
+		setntamem(CHRptr[0x10] +0x1400, 1, 1);
+		setntamem(CHRptr[0x10] +0x1800, 1, 2);
+		setntamem(CHRptr[0x10] +0x1C00, 1, 3);
+	} else
+		MMC3_syncMirror();
+}
+
+static DECLFW (writeReg) {
+	if (A &0x100) {
+		reg = V;
+		sync();
+	}
+}
+
+static void reset () {
+	reg = 0;
+	MMC3_clear();
+}
+
+static void power () {
+	reg = 0;
+	MMC3_power();
+	SetWriteHandler(0x4020, 0x5FFF, writeReg);
+}
+
+static void close () {
+	if (CHRRAM) {
+		FCEU_gfree(CHRRAM);
+		CHRRAM = NULL;
+	}
+}
+
+void Mapper512_Init (CartInfo *info) {
+	MMC3_init(info, sync, MMC3_TYPE_AX5202P, NULL, NULL, NULL, NULL);
+	WRAM_init(info, 8);
+	info->Power = power;
+	info->Reset = reset;
+	info->Close = close;
+	AddExState(&reg, 1, 0, "EXPR");
+
+	CHRRAM = (uint8 *)FCEU_gmalloc(8192);
+	SetupCartCHRMapping(0x10, CHRRAM, 8192, 1);
+	AddExState(CHRRAM, 8192, 0, "CRAM");
+}
diff --git a/src/ines.c b/src/ines.c
index c962f42..b987b4c 100644
--- a/src/ines.c
+++ b/src/ines.c
@@ -916,6 +916,7 @@ INES_BOARD_BEGIN()
 	INES_BOARD( "K-3054",                   504, Mapper504_Init         )
 	INES_BOARD( "GA-009",                   506, Mapper506_Init         )
 	INES_BOARD( "1n4148",                   511, Mapper511_Init         )
+	INES_BOARD( "Zhonggguo Daheng",         512, Mapper512_Init         )
 	INES_BOARD( "SA-9602B",                 513, SA9602B_Init           )
 	INES_BOARD( "Brilliant Com Cocoma Pack",516, Mapper516_Init        )
 	INES_BOARD( "DANCE2000",                518, UNLD2000_Init          )
diff --git a/src/ines.h b/src/ines.h
index 0dcec82..1297a22 100644
--- a/src/ines.h
+++ b/src/ines.h
@@ -396,6 +396,7 @@ void Mapper503_Init(CartInfo *);
 void Mapper504_Init(CartInfo *);
 void Mapper506_Init(CartInfo *);
 void Mapper511_Init(CartInfo *);
+void Mapper512_Init(CartInfo *);
 void Mapper516_Init(CartInfo *);
 void Mapper520_Init(CartInfo *);
 void Mapper523_Init(CartInfo *);