1 files changed, 11 insertions, 0 deletions
diff --git a/macros.asm b/macros.asm
index f153e379..969d9465 100644
--- a/macros.asm
+++ b/macros.asm
@@ -758,3 +758,14 @@ ENDC
 	endr
 	db x
 ENDM
+
+sine_wave: MACRO
+; \1: amplitude
+
+x = 0
+	rept $20
+	; Round up.
+	dw (sin(x) + (sin(x) & $ff)) >> 8
+x = x + (\1) * $40000
+	endr
+ENDM