--- xinu/h/iblock.h	2018/04/24 17:39:02	1.1.1.1
+++ xinu/h/iblock.h	2018/04/24 17:39:12	1.1.1.2
@@ -1,10 +1,10 @@
 /* iblock.h - ibtodb, ibdisp */
 
-typedef	int		IBADDR;		/* iblocks addressed 0,1,2,...	*/
+typedef	short		IBADDR;		/* iblocks addressed 0,1,2,...	*/
 
 #define	IBLEN		29		/* # d-block ptrs in an i-block	*/
-#define	IBNULL		-1		/* null pointer in i-block list	*/
-#define	IBAREA		1		/* start if iblocks on disk	*/
+#define	IBNULL		(IBADDR) -1	/* null pointer in i-block list	*/
+#define	IBAREA		1		/* start of iblocks on disk	*/
 #define	IBWDIR		TRUE		/* ibnew: write directory	*/
 #define	IBNWDIR		FALSE		/* ibnew: don't write directory	*/