1 files changed, 3 insertions, 0 deletions
diff --git a/opl/opl.h b/opl/opl.h
index 62b507f7..352e6696 100644
--- a/opl/opl.h
+++ b/opl/opl.h
@@ -36,6 +36,7 @@ typedef enum
 #define OPL_NUM_OPERATORS   21
 #define OPL_NUM_VOICES      9
 
+#define OPL_REG_WAVEFORM_ENABLE   0x01
 #define OPL_REG_TIMER1            0x02
 #define OPL_REG_TIMER2            0x03
 #define OPL_REG_TIMER_CTRL        0x04
@@ -47,11 +48,13 @@ typedef enum
 #define OPL_REGS_LEVEL            0x40
 #define OPL_REGS_ATTACK           0x60
 #define OPL_REGS_SUSTAIN          0x80
+#define OPL_REGS_WAVEFORM         0xE0
 
 // Voice registers (9 of each):
 
 #define OPL_REGS_FREQ_1           0xA0
 #define OPL_REGS_FREQ_2           0xB0
+#define OPL_REGS_FEEDBACK         0xC0
 
 // Initialise the OPL subsystem.