--- util/igmk3d.f.orig	2000-08-06 04:28:16.000000000 +0900
+++ util/igmk3d.f	2020-11-21 16:28:34.000000000 +0900
@@ -37,7 +37,7 @@
       DIMENSION IDENT(*)
       INTEGER HEAD(64)
       DATA MAXGF/9999/
-      DATA MISS/'80808080'X/
+      DATA MISS/X'80808080'/
 C
       IF (GFNO.LT.1.OR.GFNO.GT.MAXGF) GOTO 92
       CALL IGNM3D(GFNO,FILNAM)