1 files changed, 61 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libgme/nes_mmc5_apu.h b/lib/rbcodec/codecs/libgme/nes_mmc5_apu.h
new file mode 100644
index 0000000000..b696b49e97
--- /dev/null
+++ b/lib/rbcodec/codecs/libgme/nes_mmc5_apu.h
@@ -0,0 +1,61 @@
+// NES MMC5 sound chip emulator
+
+// Nes_Snd_Emu 0.2.0-pre
+#ifndef NES_MMC5_APU_H
+#define NES_MMC5_APU_H
+
+#include "blargg_common.h"
+#include "nes_apu.h"
+
+enum { mmc5_regs_addr = 0x5000 };
+enum { mmc5_regs_size = 0x16 };
+enum { mmc5_osc_count  = 3 };
+enum { mmc5_exram_size = 1024 };
+
+struct Nes_Mmc5_Apu {
+        struct Nes_Apu apu;
+        unsigned char exram [mmc5_exram_size];
+};
+
+static inline void Mmc5_init( struct Nes_Mmc5_Apu* this )
+{
+        Apu_init( &this->apu );
+}
+
+static inline void Mmc5_set_output( struct Nes_Mmc5_Apu* this, int i, struct Blip_Buffer* b )
+{
+        // in: square 1, square 2, PCM
+        // out: square 1, square 2, skipped, skipped, PCM
+        if ( i > 1 )
+                i += 2;
+        Apu_osc_output( &this->apu, i, b );
+}
+
+static inline void Mmc5_write_register( struct Nes_Mmc5_Apu* this, blip_time_t time, unsigned addr, int data )
+{
+        switch ( addr )
+        {
+        case 0x5015: // channel enables
+                data &= 0x03; // enable the square waves only
+                // fall through
+        case 0x5000: // Square 1
+        case 0x5002:
+        case 0x5003:
+        case 0x5004: // Square 2
+        case 0x5006:
+        case 0x5007:
+        case 0x5011: // DAC
+                Apu_write_register( &this->apu, time, addr - 0x1000, data );
+                break;
+        
+        case 0x5010: // some things write to this for some reason
+                break;
+        
+#ifdef BLARGG_DEBUG_H
+        default:
+                        dprintf( "Unmapped MMC5 APU write: $%04X <- $%02X\n", addr, data );
+#endif
+        }
+}
+
+#endif