--- a/src/m/plexus.h	Mon Aug 13 11:19:22 2007 +0200
+++ b/src/m/plexus.h	Mon Aug 13 11:20:41 2007 +0200
@@ -24,6 +24,11 @@
    operating system this machine is likely to run.
    USUAL-OPSYS="usg5-2"  */
 
+/* Define WORD_MACHINE if addresses and such have
+ * to be corrected before they can be used as byte counts.  */
+
+#undef WORD_MACHINE
+
 /* Now define a symbol for the cpu type, if your compiler
    does not define it automatically:
    vax, m68000, ns16000, pyramid, orion, tahoe and APOLLO
@@ -31,6 +36,14 @@
 /* Plexus predefines m68 instead of m68000. */
 #define m68000 m68
 
+/* Define EXPLICIT_SIGN_EXTEND if XINT must explicitly sign-extend
+   the bit field into an int.  In other words, if bit fields
+   are always unsigned.
+
+   If you use NO_UNION_TYPE, this flag does not matter.  */
+
+#undef EXPLICIT_SIGN_EXTEND
+
 /* Data type of load average, as read out of kmem.  */
 
 #undef LOAD_AVE_TYPE