--- freem/src/symtab_bltin.c	2025/03/09 19:50:47	1.4
+++ freem/src/symtab_bltin.c	2025/03/26 15:17:12	1.7
@@ -1,5 +1,5 @@
 /*
- *   $Id: symtab_bltin.c,v 1.4 2025/03/09 19:50:47 snw Exp $
+ *   $Id: symtab_bltin.c,v 1.7 2025/03/26 15:17:12 snw Exp $
  *      FreeM local system table and user-defined special variable table 
  *
  *  
@@ -24,6 +24,15 @@
  *   along with FreeM.  If not, see <https://www.gnu.org/licenses/>.
  *
  *   $Log: symtab_bltin.c,v $
+ *   Revision 1.7  2025/03/26 15:17:12  snw
+ *   Fall back to global-backed SSVNs when memory-backed globals fail in attempt to fix Tru64
+ *
+ *   Revision 1.6  2025/03/24 04:13:11  snw
+ *   Replace action macro dat with fra_dat to avoid symbol conflict on OS/2
+ *
+ *   Revision 1.5  2025/03/24 02:01:41  snw
+ *   Work around some OS/2 incompatibilities in symbol table code
+ *
  *   Revision 1.4  2025/03/09 19:50:47  snw
  *   Second phase of REUSE compliance and header reformat
  *
@@ -49,10 +58,11 @@
 symbol-table calls */
 /* #define DEBUG_SYM  */
 
+short st_use_shm = FALSE;
 short restoring_consts = FALSE;
 int semid_symtab;
 
-#if !defined(__OpenBSD__) && !defined(__APPLE__)
+#if !defined(__OpenBSD__) && !defined(__APPLE__) && !defined(__OS2__)
 union semun {
     int              val;    /* Value for SETVAL */
     struct semid_ds *buf;    /* Buffer for IPC_STAT, IPC_SET */
@@ -131,7 +141,13 @@ void symtab_init (void)
         fprintf (stderr, "symtab_init:  allocating partition for memory-backed globals\r\n");
         
         mbpartition = (char *) shm_alloc ((size_t) PSIZE + 2);
-        NULLPTRCHK(mbpartition,"symtab_init");
+        if (mbpartition != NULL) {
+            shm_config->hdr->use_mb_globals = TRUE;
+        }
+        else {
+            fprintf (stderr, "symtab_init:  falling back to global-backed structured system variables\r\n");
+            shm_config->hdr->use_mb_globals = FALSE;
+        }
 
         shm_config->hdr->partition = mbpartition;
         
@@ -201,6 +217,11 @@ void symtab_shm (short action, char *key
     unsigned long stptrs[128];
     register int i;
     char *old_partition = partition;
+
+    if (shm_config->hdr->use_mb_globals == FALSE) {
+        symtab_bltin (action, key, data);
+        return;
+    }
     partition = mbpartition;
 
     writing_mb = TRUE;
@@ -943,7 +964,7 @@ old0:				/* entry from getinc */
             /* end of set_sym section */
 
             
-            case dat:
+            case fra_dat:
 
 
                 /* note: we assume EOL<DELIM<ASCII */