diff --git a/B5500/b5500_cpu.c b/B5500/b5500_cpu.c
index 832a448..db301cf 100644
--- a/B5500/b5500_cpu.c
+++ b/B5500/b5500_cpu.c
@@ -3894,20 +3894,21 @@ cpu_set_size(UNIT * uptr, int32 val, CONST char *cptr, void *desc)
 {
     t_uint64            mc = 0;
     uint32              i;
+    int32               v;
 
+    v = val >> UNIT_V_MSIZE;
+    v = (v + 1) * 4096;
+    if ((v < 0) || (v > MAXMEMSIZE))
+        return SCPE_ARG;
+    for (i = v-1; i < MEMSIZE; i++)
+        mc |= M[i];
+    if ((mc != 0) && (!get_yn("Really truncate memory [N]?", FALSE)))
+        return SCPE_OK;
     cpu_unit[0].flags &= ~UNIT_MSIZE;
     cpu_unit[0].flags |= val;
     cpu_unit[1].flags &= ~UNIT_MSIZE;
     cpu_unit[1].flags |= val;
-    val >>= UNIT_V_MSIZE;
-    val = (val + 1) * 4096;
-    if ((val < 0) || (val > MAXMEMSIZE))
-        return SCPE_ARG;
-    for (i = val; i < MEMSIZE; i++)
-        mc |= M[i];
-    if ((mc != 0) && (!get_yn("Really truncate memory [N]?", FALSE)))
-        return SCPE_OK;
-    MEMSIZE = val;
+    MEMSIZE = v;
     for (i = MEMSIZE; i < MAXMEMSIZE; i++)
         M[i] = 0;
     return SCPE_OK;
diff --git a/sim_card.c b/sim_card.c
index 3f2d1df..aebc759 100644
--- a/sim_card.c
+++ b/sim_card.c
@@ -708,7 +708,9 @@ sim_read_card(UNIT * uptr)
     case MODE_CBN:
         sim_debug(DEBUG_CARD, dptr, "cbn\n");
         /* Check if first character is a tape mark */
-        if (size == 1 && ((uint8)data->cbuff[0]) == 0217) {
+        if (((uint8)data->cbuff[0]) == 0217 && 
+                   (size == 1 || (((uint8)data->cbuff[0]) & 0200) != 0)) {
+            i = 1;
             r = SCPE_EOF;
             break;
         }
@@ -748,7 +750,9 @@ sim_read_card(UNIT * uptr)
     case MODE_BCD:
         sim_debug(DEBUG_CARD, dptr, "bcd [");
         /* Check if first character is a tape mark */
-        if (size == 1 && ((uint8)data->cbuff[0]) == 0217) {
+        if (((uint8)data->cbuff[0]) == 0217 && 
+                   (size == 1 || (((uint8)data->cbuff[0]) & 0200) != 0)) {
+            i = 1;
             r = SCPE_EOF;
             break;
         }