diff --git a/imlac/imlac_cpu.c b/imlac/imlac_cpu.c
index 797d2a45..4b6823f8 100644
--- a/imlac/imlac_cpu.c
+++ b/imlac/imlac_cpu.c
@@ -62,15 +62,16 @@ static int rom_type = ROM_NONE;
 static int halt;
 uint16 memmask = 017777;
 
-static struct {
+typedef struct {
   uint16 PC;
   uint16 IR;
   uint16 MA;
   uint16 MB;
   uint16 AC;
   uint16 L;
-} *history = NULL;
-static uint32 history_i, history_j, history_m, history_n;
+} HISTORY;
+static HISTORY *history = NULL;
+static uint32 history_i, history_m, history_n;
 
 /* Function declaration. */
 static t_stat cpu_set_hist (UNIT *uptr, int32 val, CONST char *cptr, void *desc);
@@ -496,7 +497,7 @@ cpu_set_hist (UNIT *uptr, int32 val, CONST char *cptr, void *desc)
   if (r != SCPE_OK)
     return r;
 
-  history = calloc (x, sizeof (*history));
+  history = (HISTORY *)calloc (x, sizeof (*history));
   if (history == NULL)
     return SCPE_MEM;
 
diff --git a/imlac/imlac_kbd.c b/imlac/imlac_kbd.c
index 6cdb5941..1ee1bdf7 100644
--- a/imlac/imlac_kbd.c
+++ b/imlac/imlac_kbd.c
@@ -228,7 +228,7 @@ kbd_both (uint32 key)
     break;
   case SIM_KEY_F11:
     vid_set_fullscreen (!vid_is_fullscreen ());
-    break;
+    return 0;
   default:
     return 0;
   }
diff --git a/imlac/imlac_tty.c b/imlac/imlac_tty.c
index c33dc485..f8084aba 100644
--- a/imlac/imlac_tty.c
+++ b/imlac/imlac_tty.c
@@ -63,12 +63,14 @@ static uint16 stty_rom[] = {
   0010050, 0120010, 0030020, 0010044, 0110000, 0000160, 0000100, 0000017
 };
 
+#if 0 /* Unused so far. */
 static uint16 mtty_rom[] = {
   0060077, 0020010, 0104076, 0020020, 0001032, 0100011, 0002040, 0010046,
   0001031, 0074075, 0010044, 0002040, 0010053, 0001033, 0003003, 0003003,
   0003002, 0002040, 0010061, 0001033, 0120010, 0100011, 0030020, 0010053,
   0110076, 0004200, 0100040, 0001043, 0010040, 0000002, 0037700, 0037677,
 };
+#endif
 
 static UNIT tty_unit[] = {
   { UDATA (&tty_r_svc, UNIT_IDLE+UNIT_ATTABLE, 0) },