diff --git a/libsrc/atmos/waitvsync.s b/libsrc/atmos/waitvsync.s
new file mode 100644
index 000000000..6113f3da2
--- /dev/null
+++ b/libsrc/atmos/waitvsync.s
@@ -0,0 +1,18 @@
+;
+; Written by Stefan Haubenthal <polluks@sdf.org>, requires VSync hack
+;
+; void waitvsync (void);
+;
+
+        .export _waitvsync
+
+        .include "atmos.inc"
+
+.proc   _waitvsync
+
+wait:   lda     VIA::PRA2
+        and     #%00010000      ; CB1
+        bne     wait
+        rts
+
+.endproc