diff --git a/3B2/3b2_stddev.c b/3B2/3b2_stddev.c
index 14989333..aa47c344 100644
--- a/3B2/3b2_stddev.c
+++ b/3B2/3b2_stddev.c
@@ -388,7 +388,6 @@ static t_stat tod_svc(UNIT *uptr)
     sim_activate_after(uptr, 1000000/CLK_TPS);
     tmr_poll = t;
     tmxr_poll = t;
-    AIO_SET_INTERRUPT_LATENCY(tmr_poll * CLK_TPS);
     return SCPE_OK;
 }
 
diff --git a/3B2/3b2_timer.c b/3B2/3b2_timer.c
index 6c74b540..3b2f515b 100644
--- a/3B2/3b2_timer.c
+++ b/3B2/3b2_timer.c
@@ -345,8 +345,6 @@ uint32 timer_read(uint32 pa, size_t size)
            of also clearing pending interrupts */
         CSRBIT(CSRCLK, FALSE);
         CPU_CLR_INT(INT_CLOCK);
-        /* Acknowledge a clock tick */
-        sim_rtcn_tick_ack(1, TMR_CLK);
         retval = 0;
         break;
     default: