diff --git a/sim_defs.h b/sim_defs.h
index 2fd85850..5f6f7deb 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -1,6 +1,6 @@
 /* sim_defs.h: simulator definitions
 
-   Copyright (c) 1993-2014, Robert M Supnik
+   Copyright (c) 1993-2016, Robert M Supnik
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
@@ -23,9 +23,11 @@
    used in advertising or otherwise to promote the sale, use or other dealings
    in this Software without prior written authorization from Robert M Supnik.
 
-   24-Dec-14    JDB     [4.0] Added T_ADDR_FMT
-   14-Dec-14    JDB     [4.0] Extended sim_device for compatibility
-   04-Nov-14    JDB     [4.0] Added UNIT.dynflags field for tape density support
+   25-Sep-16    RMS     Removed KBD_WAIT and friends
+   08-Mar-16    RMS     Added shutdown invisible switch
+   24-Dec-14    JDB     Added T_ADDR_FMT
+   14-Dec-14    JDB     Extended sim_device for compatibility
+   04-Nov-14    JDB     Added UNIT.dynflags field for tape density support
    21-Jul-08    RMS     Removed inlining support
    28-May-08    RMS     Added inlining support
    28-Jun-07    RMS     Added IA64 VMS support (from Norm Lastovica)
@@ -267,12 +269,9 @@ typedef uint32          t_addr;
 /* Default timing parameters */
 
 #define KBD_POLL_WAIT   5000                            /* keyboard poll */
-#define KBD_MAX_WAIT    500000
 #define SERIAL_IN_WAIT  100                             /* serial in time */
 #define SERIAL_OUT_WAIT 100                             /* serial output */
 #define NOQUEUE_WAIT    10000                           /* min check time */
-#define KBD_LIM_WAIT(x) (((x) > KBD_MAX_WAIT)? KBD_MAX_WAIT: (x))
-#define KBD_WAIT(w,s)   ((w)? w: KBD_LIM_WAIT (s))
 
 /* Convert switch letter to bit mask */