diff --git a/PDP1/pdp1_dt.c b/PDP1/pdp1_dt.c
index e19677da..6c10f030 100644
--- a/PDP1/pdp1_dt.c
+++ b/PDP1/pdp1_dt.c
@@ -25,6 +25,7 @@
 
    dt           Type 550/555 DECtape
 
+   15-Mar-17    RMS     Fixed dt_seterr to clear successor states
    09-Mar-17    RMS     Fixed dt_seterr to handle nx unit select (COVERITY)
    28-Mar-15    RMS     Revised to use sim_printf
    21-Dec-06    RMS     Added 16-channel SBS support
@@ -868,6 +869,7 @@ if (uptr != NULL) {                                     /* valid unit? */
         sim_activate (uptr, dt_dctime);                 /* sched decel */
         DTS_SETSTA (DTS_DECF | (mot & DTS_DIR), 0);     /* state = decel */
         }
+    else DTS_SETSTA (mot, 0);                           /* clear 2nd, 3rd */
     }
 DT_UPDINT;
 return;
diff --git a/PDP11/pdp11_tc.c b/PDP11/pdp11_tc.c
index ca029d7b..e5782c4d 100644
--- a/PDP11/pdp11_tc.c
+++ b/PDP11/pdp11_tc.c
@@ -25,6 +25,7 @@
 
    tc           TC11/TU56 DECtape
 
+   15-Mar-17    RMS     Fixed to defer error interrupts (Paul Koning)
    14-Mar-17    RMS     Fixed spurious interrupt when setting GO (Paul Koning)
    04-Dec-16    RMS     Revised to model TCCM correctly (Josh Dersch)
    23-Oct-13    RMS     Revised for new boot setup routine
@@ -1049,7 +1050,9 @@ return SCPE_OK;
 
 /* Utility routines */
 
-/* Set error flag */
+/* Set error flag
+   Done must be deferred to allow time for interrupt setup (RSTS V4)
+*/
 
 void dt_seterr (UNIT *uptr, int32 e)
 {
@@ -1058,7 +1061,7 @@ int32 mot = DTS_GETMOT (uptr->STATE);
 tcst = tcst | e;                                        /* set error flag */
 tccm = tccm | CSR_ERR;
 if (!(tccm & CSR_DONE)) {                               /* not done? */
-    DT_SETDONE;
+    sim_activate (&dt_dev.units[DT_TIMER], dt_ctime);   /* sched done */
     }
 if (mot >= DTS_ACCF) {                                  /* ~stopped or stopping? */
     sim_cancel (uptr);                                  /* cancel activity */
@@ -1067,6 +1070,7 @@ if (mot >= DTS_ACCF) {                                  /* ~stopped or stopping?
     sim_activate (uptr, dt_dctime);                     /* sched decel */
     DTS_SETSTA (DTS_DECF | (mot & DTS_DIR), 0);         /* state = decel */
     }
+else DTS_SETSTA (mot, 0);                               /* clear 2nd, 3rd */
 return;
 }
 
diff --git a/PDP18B/pdp18b_dt.c b/PDP18B/pdp18b_dt.c
index d29f392c..4dabbdd1 100644
--- a/PDP18B/pdp18b_dt.c
+++ b/PDP18B/pdp18b_dt.c
@@ -27,6 +27,7 @@
                 (PDP-9) TC02/TU55 DECtape
                 (PDP-15) TC15/TU56 DECtape
 
+   15-Mar-17    RMS     Fixed dt_seterr to clear successor states
    09-Mar-17    RMS     Fixed dt_seterr to handle nx unit select (COVERITY)
    10-Mar-16    RMS     Added 3-cycle databreak set/show entries
    07-Mar-16    RMS     Revised for dynamically allocated memory
@@ -1283,6 +1284,7 @@ if (uptr != NULL) {                                     /* valid select? */
         sim_activate (uptr, dt_dctime);                 /* sched decel */
         DTS_SETSTA (DTS_DECF | (mot & DTS_DIR), 0);     /* state = decel */
         }
+    else DTS_SETSTA (mot, 0);                           /* clear 2nd, 3rd */
     }
 DT_UPDINT;
 return;
diff --git a/PDP8/pdp8_dt.c b/PDP8/pdp8_dt.c
index 8caf47a7..fb7d7bed 100644
--- a/PDP8/pdp8_dt.c
+++ b/PDP8/pdp8_dt.c
@@ -1,6 +1,6 @@
 /* pdp8_dt.c: PDP-8 DECtape simulator
 
-   Copyright (c) 1993-2013, Robert M Supnik
+   Copyright (c) 1993-2017, 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"),
@@ -25,6 +25,7 @@
 
    dt           TC08/TU56 DECtape
 
+   15-Mar-17    RMS     Fixed dt_seterr to clear successor states
    17-Sep-13    RMS     Changed to use central set_bootpc routine
    23-Jun-06    RMS     Fixed switch conflict in ATTACH
    07-Jan-06    RMS     Fixed unaligned register access bug (Doug Carman)
@@ -1073,6 +1074,7 @@ if (mot >= DTS_ACCF) {                                  /* ~stopped or stopping?
     sim_activate (uptr, dt_dctime);                     /* sched decel */
     DTS_SETSTA (DTS_DECF | (mot & DTS_DIR), 0);         /* state = decel */
     }
+else DTS_SETSTA (mot, 0);                               /* clear 2nd, 3rd */
 DT_UPDINT;
 return;
 }