From af173b7b6e33f463936ffa56d6564492e5ee5e4e Mon Sep 17 00:00:00 2001
From: Mark Pizzolato <mark@infocomm.com>
Date: Fri, 24 Aug 2018 11:54:42 -0700
Subject: [PATCH] TMXR: Rework modem signaling support

- Fix ineffective setting of RNG modem bit when line with DTR isn't available
- Fix logic clearing modem signal bits
- Add API to set/clear modem control behavior fo a specific line.
- return -2 status from tmxr_poll_conn when RNG has been enabled
---
 sim_tmxr.c | 14 +++++++++++---
 sim_tmxr.h |  1 +
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/sim_tmxr.c b/sim_tmxr.c
index 29cd88d5..a4a2b07b 100644
--- a/sim_tmxr.c
+++ b/sim_tmxr.c
@@ -1000,6 +1000,7 @@ SOCKET newsock;
 TMLN *lp;
 int32 *op;
 int32 i, j;
+int32 ringing = -1;
 char *address;
 char msg[512];
 uint32 poll_time = sim_os_msec ();
@@ -1094,11 +1095,12 @@ if (mp->master) {
                     (lp->ser_connect_pending == FALSE) &&
                     ((lp->modembits & TMXR_MDM_DTR) == 0)) {
                     ++ringable_count;
-                    tmxr_set_get_modem_bits (lp, TMXR_MDM_RNG, 0, NULL);
+                    lp->modembits |= TMXR_MDM_RNG;
                     tmxr_debug_connect_line (lp, "tmxr_poll_conn() - Ringing line");
                     }
                 }
             if (ringable_count > 0) {
+                ringing = -2;
                 if (mp->ring_start_time == 0) {
                     mp->ring_start_time = poll_time;
                     mp->ring_sock = newsock;
@@ -1285,7 +1287,7 @@ for (i = 0; i < mp->lines; i++) {                       /* check each line in se
 
     }
 
-return -1;                                              /* no new connections made */
+return ringing;                                         /* no new connections made */
 }
 
 /* Reset a line.
@@ -1546,7 +1548,7 @@ if ((bits_to_set & ~(TMXR_MDM_OUTGOING)) ||         /* Assure only settable bits
     return SCPE_ARG;
 before_modem_bits = lp->modembits;
 lp->modembits |= bits_to_set;
-lp->modembits &= ~(bits_to_clear | TMXR_MDM_INCOMING);
+lp->modembits &= ~bits_to_clear;
 if ((lp->sock) || (lp->serport) || (lp->loopback)) {
     if (lp->modembits & TMXR_MDM_DTR) {
         incoming_state = TMXR_MDM_DSR;
@@ -2500,6 +2502,12 @@ while (1) {
 return -1;
 }
 
+t_stat tmxr_set_line_modem_control (TMLN *lp, t_bool enab_disab)
+{
+lp->modem_control = enab_disab;
+return SCPE_OK;
+}
+
 t_stat tmxr_set_line_speed (TMLN *lp, CONST char *speed)
 {
 UNIT *uptr;
diff --git a/sim_tmxr.h b/sim_tmxr.h
index f9bf277a..23bcf4c2 100644
--- a/sim_tmxr.h
+++ b/sim_tmxr.h
@@ -260,6 +260,7 @@ t_stat tmxr_set_line_halfduplex (TMLN *lp, t_bool enable_loopback);
 t_bool tmxr_get_line_halfduplex (TMLN *lp);
 t_stat tmxr_set_line_speed (TMLN *lp, CONST char *speed);
 t_stat tmxr_set_config_line (TMLN *lp, CONST char *config);
+t_stat tmxr_set_line_modem_control (TMLN *lp, t_bool enabled);
 t_stat tmxr_set_line_unit (TMXR *mp, int line, UNIT *uptr_poll);
 t_stat tmxr_set_line_output_unit (TMXR *mp, int line, UNIT *uptr_poll);
 t_stat tmxr_set_console_units (UNIT *rxuptr, UNIT *txuptr);