--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/byte_diff.c	Thu Nov 01 14:46:11 2007 +0100
@@ -0,0 +1,16 @@
+#include "byte.h"
+
+int byte_diff(s,n,t)
+register char *s;
+register unsigned int n;
+register char *t;
+{
+  for (;;) {
+    if (!n) return 0; if (*s != *t) break; ++s; ++t; --n;
+    if (!n) return 0; if (*s != *t) break; ++s; ++t; --n;
+    if (!n) return 0; if (*s != *t) break; ++s; ++t; --n;
+    if (!n) return 0; if (*s != *t) break; ++s; ++t; --n;
+  }
+  return ((int)(unsigned int)(unsigned char) *s)
+       - ((int)(unsigned int)(unsigned char) *t);
+}