diff --git a/B5500/b5500_cpu.c b/B5500/b5500_cpu.c
index 8dcc8e6e..832a4489 100644
--- a/B5500/b5500_cpu.c
+++ b/B5500/b5500_cpu.c
@@ -3981,11 +3981,11 @@ cpu_show_hist(FILE * st, UNIT * uptr, int32 val, CONST void *desc)
             int i;
             fprintf(st, "%o %05o%o ", h->cpu, h->c & 077777, h->l);
             sim_eval = (t_value)h->a_reg;
-            fprint_sym(st, 0, &sim_eval, &cpu_unit[0], SWMASK('B'));
+            (void)fprint_sym(st, 0, &sim_eval, &cpu_unit[0], SWMASK('B'));
             fputc((h->flags & F_AROF) ? '^': ' ', st);
             fputc(' ', st);
             sim_eval = (t_value)h->b_reg;
-            fprint_sym(st, 0, &sim_eval, &cpu_unit[0], SWMASK('B'));
+            (void)fprint_sym(st, 0, &sim_eval, &cpu_unit[0], SWMASK('B'));
             fputc((h->flags & F_BROF) ? '^': ' ', st);
             fputc(' ', st);
             fprint_val(st, (t_value)h->x_reg, 8, 39, PV_RZRO);
diff --git a/B5500/b5500_dtc.c b/B5500/b5500_dtc.c
index 966a9a16..cfb11dad 100644
--- a/B5500/b5500_dtc.c
+++ b/B5500/b5500_dtc.c
@@ -363,10 +363,14 @@ t_stat dtc_srv(UNIT * uptr)
         switch(i) {
         case BufNotReady:
                 chan_set_notrdy(chan);
+                /* Fall through */
         case BufInputBusy:
+                /* Fall through */
         case BufRead:
+                /* Fall through */
         case BufReadRdy:
                 chan_set_error(chan);
+                /* Fall through */
         case BufOutBusy:
                 chan_set_eof(chan);
                 chan_set_end(chan);
@@ -782,7 +786,7 @@ t_stat dtc_setnl (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
     newln = (int32) get_uint (cptr, 10, DTC_MLINES, &r);
     if ((r != SCPE_OK) || (newln == dtc_desc.lines))
         return r;
-    if ((newln == 0) || (newln > DTC_MLINES))
+    if ((newln == 0) || (newln >= DTC_MLINES))
         return SCPE_ARG;
     newln--;
     if (newln < dtc_desc.lines) {