diff --git a/mocktest/mockingboard.h b/mocktest/mockingboard.h
index d7b57f5..a2deec1 100644
--- a/mocktest/mockingboard.h
+++ b/mocktest/mockingboard.h
@@ -39,10 +39,13 @@
 #define TONE_CHANNEL_B    2
 #define TONE_CHANNEL_C    4
 #define NOISE_CHANNEL_A   8
-#define NOISE_CHANNLE_B  16
+#define NOISE_CHANNEL_B  16
 #define NOISE_CHANNEL_C  32
 
-#define ENABLE_CHANNEL(channels) (0x3f ^ (channels))
+#define ENABLE_CHANNEL(channels)  (0x3f ^ (channels))
+#define ENABLE_ALL_TONE_CHANNELS  ENABLE_CHANNEL(TONE_CHANNEL_A|TONE_CHANNEL_B|TONE_CHANNEL_C)
+#define ENABLE_ALL_NOISE_CHANNELS ENABLE_CHANNEL(NOISE_CHANNEL_A|NOISE_CHANNEL_B|NOISE_CHANNEL_C)
+#define ENABLE_ALL_CHANNELS       ENABLE_CHANNEL(TONE_CHANNEL_A|TONE_CHANNEL_B|TONE_CHANNEL_C|NOISE_CHANNEL_A|NOISE_CHANNEL_B|NOISE_CHANNEL_C)
 
 #define MIN_AMPLITUDE       0
 #define MAX_AMPLITUDE      15