diff --git a/src/dos/cdrom.h b/src/dos/cdrom.h
index c1219c7a..4ac398af 100644
--- a/src/dos/cdrom.h
+++ b/src/dos/cdrom.h
@@ -54,6 +54,25 @@ typedef struct SCtrl {
 	Bit8u	vol[4];			// channel volume
 } TCtrl;
 
+// Conversion function from frames to Minutes/Second/Frames
+//
+template<typename T>
+inline void frames_to_msf(int frames, T *m, T *s, T *f) {
+	const int cd_fps = 75;
+	*f = frames % cd_fps;
+	frames /= cd_fps;
+	*s = frames % 60;
+	frames /= 60;
+	*m = frames;
+}
+
+// Conversion function from Minutes/Second/Frames to frames
+//
+inline int msf_to_frames(int m, int s, int f) {
+	const int cd_fps = 75;
+	return m * 60 * cd_fps + s * cd_fps + f;
+}
+
 extern int CDROM_GetMountType(char* path, int force);
 
 class CDROM_Interface