diff --git a/textio/textio.h b/textio/textio.h
index c749ea7e..2dd50046 100644
--- a/textio/textio.h
+++ b/textio/textio.h
@@ -110,6 +110,4 @@ extern void TxInit(void);
 extern void TxInitReadline(void);
 #endif
 
-#define   TX_MAX_OPEN_FILES       20
-
 #endif /* _TEXTIO_H */
diff --git a/textio/txCommands.c b/textio/txCommands.c
index e313f179..cc71bc35 100644
--- a/textio/txCommands.c
+++ b/textio/txCommands.c
@@ -64,11 +64,17 @@ bool TxDebug = FALSE;
 /* A mask of the file descriptors for all input devices.
  */
 static fd_set txInputDescriptors;
+/* Used for the 'nfds' field for select() syscall, the highest
+ * fd number that is set in the txInputDescriptors bitmask.
+ * Don't forget to plus 1 for select().
+ */
+static int txInputDescriptors_nfds;
 
+#define   TX_MAX_INPUT_DEVICES       20
 /* A table of all input devices.
  */
-static txInputDevRec txInputDevice[TX_MAX_OPEN_FILES];
-static int txLastInputEntry = -1;
+static txInputDevRec txInputDevice[TX_MAX_INPUT_DEVICES];
+static int txLastInputEntry;
 
 /* The current point -- reset by the 'setpoint' command and for each
  * interactive command.  Calls to TxClearPoint clear previous setpoints,
@@ -130,6 +136,9 @@ static TxCommand *lisp_cur_cmd = NULL;
  *
  * FD_IsZero --
  * FD_OrSet --
+ * FD_MaxFd --
+ *      Returns the highest 'fd' in the mask for select(2) nfds argument, or
+ *      -1 when 'fdmask' is empty.
  *
  *	Routines for manipulating set of file descriptors.
  *
@@ -140,9 +149,9 @@ bool
 FD_IsZero(
     const fd_set *fdmask)
 {
-    int i;
-    for (i = 0; i <= TX_MAX_OPEN_FILES; i++)
-	if (FD_ISSET(i, fdmask)) return FALSE;
+    int fd;
+    for (fd = 0; fd < FD_SETSIZE; fd++)
+	if (FD_ISSET(fd, fdmask)) return FALSE;
     return TRUE;
 }
 
@@ -151,9 +160,30 @@ FD_OrSet(
     const fd_set *fdmask,
     fd_set *dst)
 {
-    int i;
-    for (i = 0; i <= TX_MAX_OPEN_FILES; i++)
-	if (FD_ISSET(i, fdmask)) FD_SET(i, dst);
+    int fd;
+    for (fd = 0; fd < FD_SETSIZE; fd++)
+	if (FD_ISSET(fd, fdmask)) FD_SET(fd, dst);
+}
+
+/* A bitmask find max bit set operation */
+int
+FD_MaxFd(fdmask)
+    const fd_set *fdmask;
+{
+    int fd;
+    for (fd = FD_SETSIZE-1; fd >= 0; fd--) /* backwards */
+	if (FD_ISSET(fd, fdmask)) return fd;
+    return -1;
+}
+
+/* update txInputDescriptors_nfds with the correct value
+ * call this everytime txInputDescriptors is modified
+ */
+static void
+TxInputDescriptorsRecalc(void)
+{
+    int nfds = FD_MaxFd(&txInputDescriptors);
+    txInputDescriptors_nfds = (nfds >= 0) ? nfds : 0;
 }
 
 /*
@@ -468,18 +498,20 @@ TxAddInputDevice(
 				 * it is called.
 				 */
 {
-    int i;
     TxDeleteInputDevice(fdmask);
-    if (txLastInputEntry + 1 == TX_MAX_OPEN_FILES)
+    if (txLastInputEntry == TX_MAX_INPUT_DEVICES)
     {
 	TxError("Too many input devices.\n");
 	return;
     }
-    txLastInputEntry++;
+
     txInputDevice[txLastInputEntry].tx_fdmask = *fdmask;
     txInputDevice[txLastInputEntry].tx_inputProc = inputProc;
     txInputDevice[txLastInputEntry].tx_cdata = cdata;
+    txLastInputEntry++;
+
     FD_OrSet(fdmask, &txInputDescriptors);
+    TxInputDescriptorsRecalc();
 }
 
 void
@@ -520,10 +552,9 @@ TxDeleteInputDevice(
 				 * no longer active.
 				 */
 {
-    int i;
-
-    for (i = 0; i <= TX_MAX_OPEN_FILES; i++)
-	if (FD_ISSET(i, fdmask)) TxDelete1InputDevice(i);
+    int fd;
+    for (fd = 0; fd < FD_SETSIZE; fd++)
+	if (FD_ISSET(fd, fdmask)) TxDelete1InputDevice(fd);
 }
 
 void
@@ -537,18 +568,30 @@ TxDelete1InputDevice(
 	return; /* allowing things to continue is UB */
     }
 
-    int i, j;
-    for (i = 0; i <= txLastInputEntry; i++)
+restart:
     {
-	FD_CLR(fd, &(txInputDevice[i].tx_fdmask));
-	if (FD_IsZero(&txInputDevice[i].tx_fdmask))
+	int i;
+	for (i = 0; i < txLastInputEntry; i++)
 	{
-	    for (j = i+1; j <= txLastInputEntry; j++)
-		txInputDevice[j-1] = txInputDevice[j];
-	    txLastInputEntry--;
+	    FD_CLR(fd, &txInputDevice[i].tx_fdmask);
+	    if (FD_IsZero(&txInputDevice[i].tx_fdmask))
+	    {
+		int j;
+		for (j = i+1; j < txLastInputEntry; j++)
+		    txInputDevice[j-1] = txInputDevice[j];
+		txLastInputEntry--;
+		/* we shuffled entries down one, so txInputDevice[i] now
+		 * looks at potential next one to inspect, but we're about
+		 * to i++ (if we continue) and that will incorrectly skip
+		 * inspection of it.
+		 * lets just start over
+		 */
+		goto restart;
+	    }
 	}
     }
     FD_CLR(fd, &txInputDescriptors);
+    TxInputDescriptorsRecalc();
 }
 
 
@@ -968,7 +1011,7 @@ TxGetInputEvent(
 	{
 	    if (returnOnSigWinch && SigGotSigWinch) return gotSome;
 	    inputs = txInputDescriptors;
-	    numReady = select(TX_MAX_OPEN_FILES, &inputs, (fd_set *)NULL,
+	    numReady = select(txInputDescriptors_nfds + 1, &inputs, (fd_set *)NULL,
 		(fd_set *)NULL, waitTime);
 	    if (numReady <= 0) FD_ZERO(&inputs);	/* no fd is ready */
 	} while ((numReady <= 0) && (errno == EINTR));
@@ -978,20 +1021,21 @@ TxGetInputEvent(
 	    perror("magic");
 	}
 
-	for (i = 0; i <= txLastInputEntry; i++)
+	for (i = 0; numReady && i < txLastInputEntry; i++)
 	{
 	    /* This device has data on its file descriptor, call
 	     * it so that it can add events to the input queue.
 	     */
-	    for (fd = 0; fd < TX_MAX_OPEN_FILES; fd++) {
+	    for (fd = 0; fd <= txInputDescriptors_nfds; fd++) {
 		if (FD_ISSET(fd, &inputs) &&
-			    FD_ISSET(fd, &(txInputDevice[i].tx_fdmask))) {
+			    FD_ISSET(fd, &txInputDevice[i].tx_fdmask)) {
 		    lastNum = txNumInputEvents;
 		    (*(txInputDevice[i].tx_inputProc))
 			(fd, txInputDevice[i].tx_cdata); /** @invoke cb_textio_input_t */
 		    FD_CLR(fd, &inputs);
 		    /* Did this driver choose to add an event? */
 		    if (txNumInputEvents != lastNum) gotSome = TRUE;
+		    numReady--;
 		}
 	    }
 	}
@@ -1711,6 +1755,7 @@ txCommandsInit(void)
     txZeroTime.tv_sec = 0;
     txZeroTime.tv_usec = 0;
     FD_ZERO(&txInputDescriptors);
+    txInputDescriptors_nfds = 0;
     DQInit(&txInputEvents, 4);
     DQInit(&txFreeEvents, 4);
     DQInit(&txFreeCommands, 4);