Command line option -X to turn off internal XON/XOFF flow control.

vt100/main.c

@@ -12,6 +12,7 @@ int full = 0;
 int quick = 0;
 int field_rate = 1;
 float curvature = 0.1;
+int flow = 1;
 char *argv0;
 char **cmd;
 
@@ -128,7 +129,7 @@ int main (int argc, char **argv)
   sdl_capslock (0x7E); //Default is capslock.
 
   argv0 = argv[0];
-  while ((opt = getopt (argc, argv, "b:Br2fR:DC:QN:c:")) != -1) {
+  while ((opt = getopt (argc, argv, "b:Br2fR:DC:QN:c:X")) != -1) {
     switch (opt) {
     case 'B':
       /* Backspace is Rubout. */
@@ -157,6 +158,9 @@ int main (int argc, char **argv)
     case 'c':
       curvature = atof (optarg);
       break;
+    case 'X':
+      flow = 0;
+      break;
     default:
       usage();
       break;

vt100/pty.c

@@ -89,6 +89,7 @@ static void terminal_settings (int fd)
        get_baud (cfgetispeed (&new)),
        get_baud (cfgetospeed (&new)));
   xonxoff =
+    flow &&
     (new.c_iflag & IXON) != 0 &&
     new.c_cc[VSTART] == 0x11 &&
     new.c_cc[VSTOP] == 0x13;

vt100/vt100.h

@@ -45,6 +45,7 @@ extern int pty;
 extern int sound_scope;
 extern int quick;
 extern int field_rate;
+extern int flow;
 
 extern u8 vt100rom[];
 extern u8 vt100font[];