added more mappers (buggy)

1 files changed, 16 insertions, 5 deletions

diff --git a/memory.c b/memory.c
index 28c51ad..a2e094f 100644
--- a/memory.c
+++ b/memory.c
@@ -10,9 +10,11 @@ static uint8_t memory_read(struct nes_state *restrict state, uint32_t offset) {
 		return state->ram[offset & 0x07ff];
 	} else if(offset < 0x4000) {
 		return ppu_read(state, offset);
-	// } else if(offset < 0x4020) {
-	// 	// TODO: APU and I/O reads
-	// 	return 0;
+	} else if(offset == 0x4016 || offset == 0x4017) {
+		uint32_t index = offset & 1;
+		uint8_t value = (state->input_latch[index] >> state->input_bit[index]) & 1;
+		state->input_bit[index]++;
+		return value | 0x40;	// Bit 6 open bus high, bit 7 low
 	} else if(LIKELY(offset >= 0x6000)) {
 		return state->mapper.prg_read(state, offset);
 	}
@@ -30,8 +32,17 @@ static void memory_write(struct nes_state *restrict state, uint32_t offset, uint
 		ppu_write(state, offset, value);
 	} else if(offset == 0x4014) {
 		ppu_dma_4014(state, value);
-	// } else if(offset < 0x4020) {
-	// 	// TODO: APU and I/O writes
+	} 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 >= 0x6000) {
 		state->mapper.prg_write(state, offset, value);
 	}