From c40f7421d8c1ccbe008dbd2191c6642625ae4b83 Mon Sep 17 00:00:00 2001
From: Peter Fors <peter.fors@mindkiller.com>
Date: Mon, 28 Apr 2025 18:27:17 +0200
Subject: before ppu rearrangement and fix of scanline 261

---
 memory.c | 48 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 14 deletions(-)

(limited to 'memory.c')

diff --git a/memory.c b/memory.c
index 54962a5..e934136 100644
--- a/memory.c
+++ b/memory.c
@@ -5,6 +5,7 @@ __attribute__((hot))
 static uint8_t memory_read(struct nes_state *restrict state, uint32_t offset) {
 	state->cycles++;
 	ppu_tick(state);
+	// apu_tick(state);
 
 	if(LIKELY(offset < 0x2000)) {
 		return state->ram[offset & 0x07ff];
@@ -18,6 +19,10 @@ static uint8_t memory_read(struct nes_state *restrict state, uint32_t offset) {
 		state->input_bit[index]++;
 		return value | 0x40;	// Bit 6 open bus high, bit 7 low
 
+	// } else if(offset == 4015) {
+	// 	static uint32_t apuread = 0;
+	// 	// printf("%.5d apu\n", apuread++);
+
 	} else if(LIKELY(offset >= 0x6000)) {
 		return state->mapper.prg_read(state, offset);
 
@@ -29,6 +34,7 @@ __attribute__((hot))
 static void memory_write(struct nes_state *restrict state, uint32_t offset, uint8_t value) {
 	state->cycles++;
 	ppu_tick(state);
+	// apu_tick(state);
 
 	if(LIKELY(offset < 0x2000)) {
 		state->ram[offset & 0x07ff] = value;
@@ -36,21 +42,34 @@ static void memory_write(struct nes_state *restrict state, uint32_t offset, uint
 	} else if(offset < 0x4000) {
 		ppu_write(state, offset, value);
 
-	} else if(offset == 0x4014) {
-		ppu_dma_4014(state, value);
-
-	} else if(offset == 0x4016) {
-		uint8_t prev = state->input_strobe;
-		state->input_strobe = value & 1;
-
-		if(prev == 1 && (value & 1) == 0) {
-			// Latch current inputs
-			state->input_latch[0] = state->input[0];
-			state->input_latch[1] = state->input[1];
-			state->input_bit[0] = 0;
-			state->input_bit[1] = 0;
+	} else if(offset < 0x4018) {
+		// APU + joypad + DMA
+		if(offset == 0x4014) {
+			ppu_dma_4014(state, value);
+
+		// } else if(offset == 0x4015) {	// DMC Enable (APU)
+		// 	state->apu.dmc_dma_enabled = (value & 0x10) ? 1 : 0;
+
+		} else if(offset == 0x4016) {
+			uint8_t prev = state->input_strobe;
+			state->input_strobe = value & 1;
+
+			if(prev == 1 && (value & 1) == 0) {
+				// Latch current inputs
+				state->input_latch[0] = state->input[0];
+				state->input_latch[1] = state->input[1];
+				state->input_bit[0] = 0;
+				state->input_bit[1] = 0;
+			}
+
+		// } else if(offset == 0x4017) {	// Frame Counter (APU)
+		// 	state->apu.mode = (value >> 7) & 1;
+		// 	state->apu.irq_inhibit = (value >> 6) & 1;
+		// 	state->apu.frame_cycle = 0;
+		// 	if(state->apu.irq_inhibit) {
+		// 		state->apu.irq_pending = 0;
+		// 	}
 		}
-
 	} else if(offset >= 0x6000) {
 		state->mapper.prg_write(state, offset, value);
 	}
@@ -73,6 +92,7 @@ __attribute__((hot))
 static uint8_t memory_read_dummy(struct nes_state *restrict state, uint32_t offset) {
 	state->cycles++;
 	ppu_tick(state);
+	// apu_tick(state);
 
 	if(UNLIKELY(offset >= 0x2000 && offset < 0x4000)) {
 		return ppu_read(state, offset);
-- 
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