From aeefc45355b7386f74eef9593e72fc2339f4acc0 Mon Sep 17 00:00:00 2001
From: Neil Webber <neil@webber.com>
Date: Thu, 9 May 2024 10:26:26 -0500
Subject: [PATCH] Provide option to send telnet initialization sequences to
 console

---
 boot.py |  9 ++++++---
 kl11.py | 36 +++++++++++++++++++++++++++++++++++-
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/boot.py b/boot.py
index bf28b3d..36a0ab2 100644
--- a/boot.py
+++ b/boot.py
@@ -308,11 +308,12 @@ def boot_lda(p, fname, /, *, force_run=True, msg=None):
     return rawaddr
 
 
-def make_unix_machine(*, loglevel='INFO', drivenames=[], rk=False):
+def make_unix_machine(*, loglevel='INFO', drivenames=[],
+                      rk=False, telnet=False):
     p = PDP1170(loglevel=loglevel)
 
     p.associate_device(KW11(p.ub), 'KW')    # line clock
-    p.associate_device(KL11(p.ub), 'KL')    # console
+    p.associate_device(KL11(p.ub, send_telnet=telnet), 'KL')    # console
     if rk:
         p.associate_device(RK11(p.ub, *drivenames), 'RK')    # disk drive
     else:
@@ -343,6 +344,8 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser()
     parser.add_argument('--debug', action='store_true')
     parser.add_argument('--drive', action='append', default=[], dest='drives')
+    parser.add_argument('--telnet', action='store_true',
+                        help="Send RFC854 sequences to console on start")
     parser.add_argument('--rk', action='store_true')
     parser.add_argument('--instlog', action='store_true')
     parser.add_argument('--lda', action='store', default=None)
@@ -365,7 +368,7 @@ if __name__ == "__main__":
         else:
             runoptions['breakpoint'] = breakpoints.MultiBreakpoint(*bkpts)
 
-    p = make_unix_machine(**pdpoptions, rk=args.rk)
+    p = make_unix_machine(**pdpoptions, rk=args.rk, telnet=args.telnet)
 
     unixboot_options = {}
     if args.bootmsg:
diff --git a/kl11.py b/kl11.py
index 8fcaeaa..6aa3f4d 100644
--- a/kl11.py
+++ b/kl11.py
@@ -46,10 +46,17 @@ class KL11:
     SERVERHOST = ''
     SERVERPORT = 1170
 
-    def __init__(self, ub, baseaddr=KL11_DEFAULT):
+    def __init__(self, ub, /, *, baseaddr=KL11_DEFAULT, send_telnet=False):
+        """Initialize the emulated console. Listens on port 1170.
+
+        Argument send_telnet (True/False, default False): controls whether
+        RFC854 sequences to turn off echo, etc will be sent.
+        """
+
         self.addr = baseaddr
         self.ub = ub
         self.ub.register(ub.autobyte(self.klregs), baseaddr, 4)
+        self.send_telnet = send_telnet
 
         # output characters are just queued (via tq) to the output thread
         # input characters have to undergo a more careful 1-by-1
@@ -71,6 +78,30 @@ class KL11:
         self._t = threading.Thread(target=self._connectionserver, daemon=True)
         self._t.start()
 
+    def _telnetsequences(self, s):
+        """If telnet is being used to connect, turn off local echo etc."""
+
+        dont_auth = bytes((0xff, 0xf4, 0x25))
+        s.sendall(dont_auth)
+
+        suppress_goahead = bytes((0xff, 0xfb, 0x03))
+        s.sendall(suppress_goahead)
+
+        dont_linemode = bytes((0xff, 0xfe, 0x22))
+        s.sendall(dont_linemode)
+
+        dont_new_env = bytes((0xff, 0xfe, 0x27))
+        s.sendall(dont_new_env)
+
+        will_echo = bytes((0xff, 0xfb, 0x01))
+        s.sendall(will_echo)
+
+        dont_echo = bytes((0xff, 0xfe, 0x01))
+        s.sendall(dont_echo)
+
+        noecho = bytes((0xff, 0xfd, 0x2d))
+        s.sendall(noecho)
+
     def klregs(self, addr, cycle, /, *, value=None):
         if cycle == BusCycle.RESET:
             self.rcdone = False
@@ -160,6 +191,9 @@ class KL11:
         while True:
             s, addr = serversocket.accept()
 
+            if self.send_telnet:
+                self._telnetsequences(s)
+
             outthread = threading.Thread(target=_outloop, args=(self.tq, s))
             inthread = threading.Thread(target=_inloop, args=(s,))