From e7cb21c7dc48355f262f784389eddbc544ffa680 Mon Sep 17 00:00:00 2001
From: Richard Cornwell <rcornwell@github.com>
Date: Sat, 7 Mar 2020 14:40:53 -0500
Subject: [PATCH] KA10: CTY no longer polls for input when it has pending data.

---
 PDP10/kx10_cty.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/PDP10/kx10_cty.c b/PDP10/kx10_cty.c
index fb2b148..d987f8c 100644
--- a/PDP10/kx10_cty.c
+++ b/PDP10/kx10_cty.c
@@ -136,10 +136,10 @@ t_stat ctyo_svc (UNIT *uptr)
     int32   ch;
 
     if (uptr->DATA != 0) {
-    ch = sim_tt_outcvt ( uptr->DATA, TT_GET_MODE (uptr->flags)) ;
-    if ((r = sim_putchar_s (ch)) != SCPE_OK) {   /* output; error? */
-        sim_activate (uptr, uptr->wait);               /* try again */
-        return ((r == SCPE_STALL)? SCPE_OK: r);        /* !stall? report */
+        ch = sim_tt_outcvt ( uptr->DATA, TT_GET_MODE (uptr->flags)) ;
+        if ((r = sim_putchar_s (ch)) != SCPE_OK) {   /* output; error? */
+            sim_activate (uptr, uptr->wait);               /* try again */
+            return ((r == SCPE_STALL)? SCPE_OK: r);        /* !stall? report */
         }
     }
     uptr->STATUS &= ~TEL_BSY;
@@ -154,6 +154,8 @@ t_stat ctyi_svc (UNIT *uptr)
 
     sim_clock_coschedule (uptr, tmxr_poll);
                                                        /* continue poll */
+    if (uptr->STATUS & KEY_RDY)
+        return SCPE_OK;
     if ((ch = sim_poll_kbd ()) < SCPE_KFLAG)           /* no char or error? */
         return ch;
     if (ch & SCPE_BREAK)                               /* ignore break */