x48 is a very old program but it works fault free also on new
        Linux systems (as of 2003 ;-). You need however to patch the file timer.c
        and add the line "#include <time.h>": 
--- timer.c.orig
+++ timer.c
@@ -44,6 +44,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <sys/time.h>
+#include <time.h>
 
 #include "timer.h"
 #include "debugger.h"