From e28ad1546509de31b706f0fd300a906e5bc55199 Mon Sep 17 00:00:00 2001
From: Peter Fors <peter.fors@mindkiller.com>
Date: Thu, 8 May 2025 21:03:43 +0200
Subject: new and changed mappers

---
 mappers/mapper_001_0.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 mappers/mapper_001_0.c

(limited to 'mappers/mapper_001_0.c')

diff --git a/mappers/mapper_001_0.c b/mappers/mapper_001_0.c
new file mode 100644
index 0000000..519738e
--- /dev/null
+++ b/mappers/mapper_001_0.c
@@ -0,0 +1,121 @@
+
+__attribute__((section(".mapper_001_0"), hot))
+static uint8_t mapper_001_0_prg_read(struct nes_state *state, uint32_t addr) {
+	struct mapper_001_0 *mapper = (struct mapper_001_0 *)&state->map;
+	if(addr >= 0x8000) {
+		if(addr < 0xc000) {
+			return mapper->prg_rom_0[addr & 0x3fff];
+		} else {
+			return mapper->prg_rom_1[addr & 0x3fff];
+		}
+	}
+	return 0;
+}
+
+__attribute__((section(".mapper_001_0"), hot))
+static void mapper_001_0_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) {
+	struct mapper_001_0 *mapper = (struct mapper_001_0 *)&state->map;
+	if(addr < 0x8000) return;
+
+	if(value & 0x80) {
+		mapper->shift = 0;
+		mapper->shift_count = 0;
+		mapper->control |= 0x0c;
+		return;
+	}
+
+	mapper->shift |= (value & 1) << mapper->shift_count;
+	mapper->shift_count++;
+
+	if(mapper->shift_count == 5) {
+		uint32_t bank;
+		uint8_t reg = (addr >> 13) & 0x03;
+		switch(reg) {
+			case 0: {// Control
+				mapper->control = mapper->shift;
+			} break;
+
+			case 1: { // CHR bank 0
+				mapper->chr_bank0 = mapper->shift;
+				mapper->chr_bank_0 = state->chr_rom + (mapper->chr_bank0 * 0x1000);
+			} break;
+
+			case 2: { // CHR bank 1
+				mapper->chr_bank1 = mapper->shift;
+				mapper->chr_bank_1 = state->chr_rom + (mapper->chr_bank1 * 0x1000);
+			} break;
+
+			case 3: { // PRG bank
+				mapper->prg_bank = mapper->shift & 0x0f;
+				if(mapper->control & 0x08) {
+					// 16KB bank switching
+					if(mapper->control & 0x04) {
+						mapper->prg_rom_0 = state->prg_rom + 0x4000 * 0;
+						mapper->prg_rom_1 = state->prg_rom + 0x4000 * mapper->prg_bank;
+					} else {
+						mapper->prg_rom_0 = state->prg_rom + 0x4000 * mapper->prg_bank;
+						mapper->prg_rom_1 = state->prg_rom + 0x4000 * (state->ines.prg_size / 0x4000 - 1);
+					}
+				} else {
+					// 32KB mode
+					bank = (mapper->prg_bank & 0x0e) * 0x4000;
+					mapper->prg_rom_0 = state->prg_rom + bank;
+					mapper->prg_rom_1 = state->prg_rom + bank + 0x4000;
+				}
+			} break;
+		}
+		mapper->shift = 0;
+		mapper->shift_count = 0;
+	}
+}
+
+__attribute__((section(".mapper_001_0"), hot))
+static uint8_t mapper_001_0_chr_read(struct nes_state *state, uint32_t addr) {
+	struct mapper_001_0 *mapper = (struct mapper_001_0 *)&state->map;
+	if(mapper->control & 0x10) {
+		// 4KB mode
+		if(addr < 0x1000) {
+			return mapper->chr_bank_0[addr];
+		} else {
+			return mapper->chr_bank_1[addr - 0x1000];
+		}
+	} else {
+		// 8KB mode
+		return mapper->chr_bank_0[addr];
+	}
+}
+
+__attribute__((section(".mapper_001_0"), hot))
+static void mapper_001_0_chr_write(struct nes_state *state, uint32_t addr, uint8_t value) {
+	// CHR RAM write (if present)
+	state->chr_ram[addr] = value;
+}
+
+__attribute__((section(".mapper_001_0"), hot))
+static uint8_t mapper_001_0_ciram_read(struct nes_state *state, uint32_t addr) {
+	return state->ciram[addr & 0x3ff];
+}
+
+__attribute__((section(".mapper_001_0"), hot))
+static void mapper_001_0_ciram_write(struct nes_state *state, uint32_t addr, uint8_t value) {
+	state->ciram[addr & 0x3ff] = value;
+}
+
+__attribute__((section(".mapper_001_0")))
+static void mapper_001_0_init(struct nes_state *state) {
+	struct mapper_001_0 *mapper = (struct mapper_001_0 *)&state->map;
+
+	mapper->control = 0x0c;
+	mapper->prg_rom_0 = state->prg_rom;
+	mapper->prg_rom_1 = state->prg_rom + (state->ines.prg_size - 0x4000);
+
+	mapper->chr_bank_0 = state->chr_rom;
+	mapper->chr_bank_1 = state->chr_rom + 0x1000;
+
+	state->mapper.prg_read		= mapper_001_0_prg_read;
+	state->mapper.prg_write		= mapper_001_0_prg_write;
+	state->mapper.chr_read		= mapper_001_0_chr_read;
+	state->mapper.chr_write		= mapper_001_0_chr_write;
+	state->mapper.ciram_read	= mapper_001_0_ciram_read;
+	state->mapper.ciram_write	= mapper_001_0_ciram_write;
+}
-- 
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