diff --git a/sim_console.c b/sim_console.c
index 6e707367..d4042693 100644
--- a/sim_console.c
+++ b/sim_console.c
@@ -1740,7 +1740,7 @@ t_stat sim_set_noserial (int32 flag, CONST char *cptr)
 {
 if (cptr && (*cptr != 0))                               /* too many arguments? */
     return SCPE_2MARG;
-if (sim_con_ldsc.serport == 0)                  /* ignore if already closed */
+if (sim_con_ldsc.serport == 0)                          /* ignore if already closed */
     return SCPE_OK;
 return tmxr_close_master (&sim_con_tmxr);               /* close master socket */
 }
diff --git a/sim_tmxr.c b/sim_tmxr.c
index 9390f469..01e4d336 100644
--- a/sim_tmxr.c
+++ b/sim_tmxr.c
@@ -696,9 +696,14 @@ int32 i = lp->txbpr;
 if (lp->loopback)
     return loop_write (lp, &(lp->txb[i]), length);
 
-if (lp->serport)                                        /* serial port connection? */
-    return sim_write_serial (lp->serport, &(lp->txb[i]), length);
-
+if (lp->serport) {                                      /* serial port connection? */
+    if (sim_gtime () < lp->txnexttime)
+        return 0;
+    written = sim_write_serial (lp->serport, &(lp->txb[i]), length);
+    if (written > 0)
+        lp->txnexttime = floor (sim_gtime () + (lp->txdelta * sim_timer_inst_per_sec ()));
+    return written;
+    }
 else {                                                  /* Telnet connection */
     written = sim_write_sock (lp->sock, &(lp->txb[i]), length);
 
@@ -2347,6 +2352,9 @@ if (uptr)
     uptr->wait = lp->rxdelta;
 if (lp->rxbpsfactor == 0.0)
     lp->rxbpsfactor = TMXR_RX_BPS_UNIT_SCALE;
+lp->txbps = lp->rxbps;
+lp->txdelta = lp->rxdelta;
+lp->txnexttime = lp->rxnexttime;
 return SCPE_OK;
 }
 
diff --git a/sim_tmxr.h b/sim_tmxr.h
index 053f3a2f..17c1f9e9 100644
--- a/sim_tmxr.h
+++ b/sim_tmxr.h
@@ -171,6 +171,9 @@ struct tmln {
 #define TMXR_RX_BPS_UNIT_SCALE 1000000.0
     uint32              rxdelta;                        /* rcv inter character min time (usecs) */
     double              rxnexttime;                     /* min time for next receive character */
+    uint32              txbps;                          /* xmt bps speed (0 - unlimited) */
+    uint32              txdelta;                        /* xmt inter character min time (usecs) */
+    double              txnexttime;                     /* min time for next transmit character */
     uint8               *txpb;                          /* xmt packet buffer */
     uint32              txpbsize;                       /* xmt packet buffer size */
     uint32              txppsize;                       /* xmt packet packet size */