diff --git a/sim_tape.c b/sim_tape.c
index b347d7b8..6728971b 100644
--- a/sim_tape.c
+++ b/sim_tape.c
@@ -124,7 +124,7 @@ static const uint32 bpi [] = {                          /* tape density table, i
 
 static t_stat sim_tape_ioerr (UNIT *uptr);
 static t_stat sim_tape_wrdata (UNIT *uptr, uint32 dat);
-static uint32 sim_tape_tpc_map (UNIT *uptr, t_addr *map);
+static uint32 sim_tape_tpc_map (UNIT *uptr, t_addr *map, uint32 mapsize);
 static t_stat sim_tape_simh_check (UNIT *uptr);
 static t_stat sim_tape_e11_check (UNIT *uptr);
 static t_addr sim_tape_tpc_fnd (UNIT *uptr, t_addr *map);
@@ -133,7 +133,7 @@ static void sim_tape_data_trace (UNIT *uptr, const uint8 *data, size_t len, cons
 
 struct tape_context {
     DEVICE              *dptr;              /* Device for unit (access to debug flags) */
-    uint32              dbit;               /* debugging bit */
+    uint32              dbit;               /* debugging bit for trace */
     uint32              auto_format;        /* Format determined dynamically */
 #if defined SIM_ASYNCH_IO
     int                 asynch_io;          /* Asynchronous Interrupt scheduling enabled */
@@ -485,7 +485,7 @@ switch (MT_GET_FMT (uptr)) {                            /* case on format */
         break;
 
     case MTUF_F_TPC:                                    /* TPC */
-        objc = sim_tape_tpc_map (uptr, NULL);           /* get # objects */
+        objc = sim_tape_tpc_map (uptr, NULL, 0);        /* get # objects */
         if (objc == 0) {                                /* tape empty? */
             sim_tape_detach (uptr);
             return SCPE_FMT;                            /* yes, complain */
@@ -496,7 +496,7 @@ switch (MT_GET_FMT (uptr)) {                            /* case on format */
             return SCPE_MEM;                            /* no, complain */
             }
         uptr->hwmark = objc + 1;                        /* save map size */
-        sim_tape_tpc_map (uptr, (t_addr *) uptr->filebuf);      /* fill map */
+        sim_tape_tpc_map (uptr, (t_addr *) uptr->filebuf, objc);/* fill map */
         break;
 
     default:
@@ -2142,20 +2142,22 @@ return SCPE_OK;
 
 /* Map a TPC format tape image */
 
-static uint32 sim_tape_tpc_map (UNIT *uptr, t_addr *map)
+static uint32 sim_tape_tpc_map (UNIT *uptr, t_addr *map, uint32 mapsize)
 {
-t_addr tpos;
+t_addr tpos, leot;
 t_addr tape_size;
 t_tpclnt bc, last_bc;
-t_bool had_double_tape_mark = FALSE;
+uint32 had_double_tape_mark = 0;
 size_t i;
 uint32 objc, sizec;
 uint32 *countmap = NULL;
+uint8 *recbuf = NULL;
 DEVICE *dptr = find_dev_from_unit (uptr);
 
 if ((uptr == NULL) || (uptr->fileref == NULL))
     return 0;
 countmap = calloc (65536, sizeof(*countmap));
+recbuf = malloc (65536);
 tape_size = (t_addr)sim_fsize (uptr->fileref);
 sim_debug (MTSE_DBG_STR, dptr, "tpc_map: tape_size: %" T_ADDR_FMT "u\n", tape_size);
 for (objc = 0, sizec = 0, tpos = 0;; ) {
@@ -2166,19 +2168,38 @@ for (objc = 0, sizec = 0, tpos = 0;; ) {
     if (countmap[bc] == 0)
         sizec++;
     ++countmap[bc];
-    if (map)
+    if (map && (objc < mapsize))
         map[objc] = tpos;
-    sim_debug (MTSE_DBG_STR, dptr, "tpc_map: %d byte count at pos: %" T_ADDR_FMT "u\n", bc, tpos);
+    if (bc) {
+        sim_debug (MTSE_DBG_STR, dptr, "tpc_map: %d byte count at pos: %" T_ADDR_FMT "u\n", bc, tpos);
+        if (sim_deb && (dptr->dctrl & MTSE_DBG_STR)) {
+            sim_fread (recbuf, 1, bc, uptr->fileref);
+            sim_data_trace(dptr, uptr, ((dptr->dctrl & MTSE_DBG_DAT) ? recbuf : NULL), "", bc, "Data Record", MTSE_DBG_STR);
+            }
+        }
+    else
+        sim_debug (MTSE_DBG_STR, dptr, "tpc_map: tape mark at pos: %" T_ADDR_FMT "u\n", tpos);
     objc++;
     tpos = tpos + ((bc + 1) & ~1) + sizeof (t_tpclnt);
-    if ((bc == 0) && (last_bc == 0))    /* double tape mark? */
-        had_double_tape_mark |= TRUE;
+    if ((bc == 0) && (last_bc == 0)) {  /* double tape mark? */
+        had_double_tape_mark = objc;
+        leot = tpos;
+        }
     last_bc = bc;
     }
-sim_debug (MTSE_DBG_STR, dptr, "tpc_map: objc: %d, sizec: %d\n", objc, sizec);
+sim_debug (MTSE_DBG_STR, dptr, "tpc_map: objc: %u, different record sizes: %u\n", objc, sizec);
+for (i=0; i<65535; i++) {
+    if (countmap[i]) {
+        if (i == 0)
+            sim_debug (MTSE_DBG_STR, dptr, "tpc_map: summary - %u tape marks\n", countmap[i]);
+        else
+            sim_debug (MTSE_DBG_STR, dptr, "tpc_map: summary - %u %d byte record%s\n", countmap[i], (int)i, (countmap[i] > 1) ? "s" : "");
+        }
+    }
 if (((last_bc != 0xffff) && 
-     (tpos > tape_size))    ||
-    (!had_double_tape_mark) ||
+     (tpos > tape_size) &&
+     (!had_double_tape_mark))    ||
+    (!had_double_tape_mark)      ||
     ((objc == countmap[0]) && 
      (countmap[0] != 2))) {     /* Unreasonable format? */
     if (last_bc != 0xffff)
@@ -2188,13 +2209,20 @@ if (((last_bc != 0xffff) &&
     if (objc == countmap[0])
         sim_debug (MTSE_DBG_STR, dptr, "tpc_map: ERROR tape cnly contains tape marks\n");
     free (countmap);
+    free (recbuf);
     return 0;
     }
 
+if ((last_bc != 0xffff) && (tpos > tape_size)) {
+    sim_debug (MTSE_DBG_STR, dptr, "tpc_map: WARNING unexpected EOT byte count: %d, double tape mark before %" T_ADDR_FMT "u provides logical EOT\n", last_bc, leot);
+    objc = had_double_tape_mark;
+    tpos = leot;
+    }
 if (map)
     map[objc] = tpos;
 sim_debug (MTSE_DBG_STR, dptr, "tpc_map: OK objc: %d\n", objc);
 free (countmap);
+free (recbuf);
 return objc;
 }