diff --git a/configure.in b/configure.in
index 62487e4..6bd4dec 100644
--- a/configure.in
+++ b/configure.in
@@ -68,7 +68,7 @@ define(S48_USCORE, [dnl
 	if ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} -o a.out conftest.c ${LIBS} &&
 	nm a.out | grep _fnord >/dev/null; then
 		AC_MSG_RESULT([yes])
-		AC_DEFINE(USCORE)
+		AC_DEFINE(USCORE, 1, Define to 1 if symbols start with _)
 	else
 		AC_MSG_RESULT([no])
 	fi
@@ -89,20 +89,6 @@ AC_DEFUN(SCSH_TZNAME,[
   fi
 ])
 
-dnl -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-AC_DEFUN(SCSH_GMTOFF,[
-  AC_MSG_CHECKING(for gmtoff)
-  AC_CACHE_VAL(scsh_cv_gmtoff,[
-    AC_TRY_COMPILE([#include <time.h>], 
-		   [struct tm time;
-		    return time.tm_gmtoff;],
-                   scsh_cv_gmtoff=yes,
-                   scsh_cv_gmtoff=no)])
-  AC_MSG_RESULT($scsh_cv_gmtoff)
-  if test $scsh_cv_gmtoff = yes; then
-    AC_DEFINE(HAVE_GMTOFF)
-  fi
-])
 dnl -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 AC_DEFUN(SCSH_ELF, [
   AC_MSG_CHECKING(for ELF)
@@ -185,7 +171,7 @@ AC_DEFUN(SCSH_CONST_SYS_ERRLIST,[
                    scsh_cv_const_sys_errlist=no)])
   AC_MSG_RESULT($scsh_cv_const_sys_errlist)
   if test $scsh_cv_const_sys_errlist = yes; then
-    AC_DEFINE(HAVE_CONST_SYS_ERRLIST)
+    AC_DEFINE(HAVE_CONST_SYS_ERRLIST, 1, const char* sys_errlist)
   fi
 ])
 
@@ -199,7 +185,8 @@ AC_DEFUN(SCSH_SOCKLEN_T,[
                                           int accept (int, struct sockaddr *, size_t *);
                                          ],[],[
                                               AC_MSG_RESULT(size_t)
-                                         AC_DEFINE(socklen_t,size_t)], [
+                                         AC_DEFINE(socklen_t,
+					size_t, Define to type of socklen_t)], [
                    AC_MSG_RESULT(int)
                    AC_DEFINE(socklen_t,int)])])
 ])
@@ -234,7 +221,7 @@ AC_INIT(c/scheme48vm.c)
     CC="cc -Xa"
     CFLAGS="-O"
     LDFLAGS="-O -Wl,-Bexport"
-    AC_DEFINE(HAVE_HARRIS)
+    AC_DEFINE(HAVE_HARRIS, 1, Define to 1 on m88k-harris-cxux)
   ;;
     
   ## DEC Ultrix
@@ -244,7 +231,7 @@ AC_INIT(c/scheme48vm.c)
       LDFLAGS=-N
     fi
   ;;
-  	
+
   ## HP 9000 series 700 and 800, running HP/UX
   hppa*-hp-hpux* )
     dir=hpux
@@ -252,9 +239,9 @@ AC_INIT(c/scheme48vm.c)
     if test ${CC} = cc; then
       CFLAGS="-Ae -O +Obb1800"
     fi
-    AC_DEFINE(_HPUX_SOURCE)
-    AC_DEFINE(hpux)
-    AC_DEFINE(_XOPEN_SOURCE_EXTENDED)
+    AC_DEFINE(_HPUX_SOURCE, 1, Define to 1 to compile on HP/UX)
+    AC_DEFINE(hpux, 1, Define to 1 on HP/UX)
+    AC_DEFINE(_XOPEN_SOURCE_EXTENDED, 1, Define to 1 to compile on HP/UX)
   ;;
  
   ## IBM AIX
@@ -311,7 +298,7 @@ AC_INIT(c/scheme48vm.c)
   
   ## NT - cygwin32
   *-*-cygwin* )
-    AC_DEFINE(CYGWIN)
+    AC_DEFINE(CYGWIN, 1, Define to 1 on cygwin)
     dir=cygwin32
     EXEEXT=".exe"
   ;;
@@ -345,29 +332,31 @@ esac
      AC_CHECK_HEADERS(crypt.h)	
      AC_CHECK_FUNCS(gettimeofday ftime nlist select setitimer sigaction vasprintf)
      SCSH_SOCKLEN_T	
-     AC_CHECK_FUNC(dlopen, AC_DEFINE(HAVE_DLOPEN),
-			   AC_CHECK_FUNC(nlist, [LIBOBJS="$LIBOBJS c/fake/libdl1.o"],
-						[LIBOBJS="$LIBOBJS c/fake/libdl2.o"]))
+     AC_CHECK_FUNC(dlopen, [AC_DEFINE(HAVE_DLOPEN, 
+				1, Define to 1 if the interface to the dynamic linker exists)],
+			   [AC_CHECK_FUNC(nlist, [AC_LIBOBJ([c/fake/libdl1])],
+	       					 [AC_LIBOBJ([c/fake/libdl2])])])
      AC_CHECK_FUNCS(socket chroot)
-     AC_CHECK_FUNC(strerror, AC_DEFINE(HAVE_STRERROR),
-			      [LIBOBJS="$LIBOBJS c/fake/strerror.o"])
+     AC_CHECK_FUNC(strerror, AC_DEFINE(HAVE_STRERROR, 
+					1, Define to 1 if you have the strerror function),
+			      [AC_LIBOBJ([c/fake/strerror])])
 
-     AC_CHECK_FUNC(seteuid, AC_DEFINE(HAVE_SETEUID),
-	AC_CHECK_FUNC(setreuid, AC_DEFINE(HAVE_SETREUID), 
-	AC_MSG_ERROR("Neither setegid nor setregid defined. Cannot continue.")))
+     AC_CHECK_FUNC(seteuid, [AC_DEFINE(HAVE_SETEUID, 
+					1, Define to 1 if you have the seteuid function)],
+ 	[AC_CHECK_FUNC(setreuid, [AC_DEFINE(HAVE_SETREUID, 
+						1, Define to 1 if you have the setreuid function)],
+ 	[AC_MSG_ERROR("Neither setegid nor setregid defined. Cannot continue.")])])
 
-     AC_CHECK_FUNC(setegid, AC_DEFINE(HAVE_SETEGID),
-	AC_CHECK_FUNC(setregid, AC_DEFINE(HAVE_SETREGID), 
-	AC_MSG_ERROR("Neither setegid nor setregid defined. Cannot continue.")))
+     AC_CHECK_FUNC(setegid, [AC_DEFINE(HAVE_SETEGID, 
+					1, Define to 1 if you have the setegid function)],
+ 	[AC_CHECK_FUNC(setregid, [AC_DEFINE(HAVE_SETREGID, 
+						1, Define to 1 if you have the setregid function)], 
+         	[AC_MSG_ERROR("Neither setegid nor setregid defined. Cannot continue.")])])
 
 
-     AC_MSG_CHECKING([n_name])
-     AC_TRY_LINK([#include <nlist.h>],
-		 [struct nlist name_list;
-		  name_list.n_name = "foo";],
-		 AC_DEFINE(NLIST_HAS_N_NAME)
-		 AC_MSG_RESULT([yes]),
-		 AC_MSG_RESULT([no]))
+     AC_CHECK_MEMBER(struct nlist.n_name,
+	[AC_DEFINE(NLIST_HAS_N_NAME, 1, Define to 1 if struct nlist.n_name exists)],,
+	[#include <nlist.h>])
      AC_MSG_CHECKING([__NEXT__])
      AC_TRY_LINK(,[
 #ifdef	__NeXT__
@@ -383,12 +372,13 @@ fail
      S48_USCORE
      S48_RDYNAMIC
      AC_STRUCT_TIMEZONE
-     SCSH_GMTOFF
+     AC_CHECK_MEMBER(struct tm.tm_gmtoff,
+	AC_DEFINE(HAVE_GMTOFF, 1, Define to 1 if struct tm has member tm_gmtoff))
+	
      SCSH_CONST_SYS_ERRLIST	
      CFLAGS1=${CFLAGS}
 
      AC_SUBST(CFLAGS)
-     AC_SUBST(LIBOBJS)
      AC_SUBST(LDFLAGS)