diff --git a/templates/index.html b/templates/index.html
index 9129d9d..76504c2 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -148,6 +148,7 @@ <h1 style="margin:0;">artNC</h1>
       <textarea id="acode" placeholder="Wklej ACODE tutaj albo wygeneruj w zakładkach Generator / Text outline..."></textarea>
 
       <div class="row">
+        <label>Start line: <input id="start_line" value="1" inputmode="numeric" style="width:100px"></label>
         <button class="btn" id="start">Start</button>
         <button class="btn" id="pause">Pause</button>
         <button class="btn" id="resume">Resume</button>
@@ -161,7 +162,10 @@ <h1 style="margin:0;">artNC</h1>
     <div class="box">
       <div class="row">
         <div class="pill">Progress: <span id="progress" class="mono">0/0</span></div>
-        <div class="pill">Last: <span id="lastok" class="mono">-</span></div>
+        <div class="pill">Last OK: <span id="lastok" class="mono">-</span></div>
+        <div class="pill">Last OK line: <span id="lastokline" class="mono">-</span></div>
+        <div class="pill">Est. total: <span id="esttotal" class="mono">-</span></div>
+        <div class="pill">Est. remaining: <span id="estremaining" class="mono">-</span></div>
       </div>
 
       <div style="height:10px"></div>
@@ -175,6 +179,17 @@ <h1 style="margin:0;">artNC</h1>
 
     <div style="height:12px"></div>
 
+    <div class="box">
+      <div class="row" style="align-items: center;">
+        <div style="font-weight:700;">Manual / serial</div>
+        <input id="manual_cmd" placeholder="Wpisz komendę ACODE / serial" style="flex:1; min-width:280px;">
+        <button class="btn" id="manual_send">Send</button>
+      </div>
+      <div class="small">Wysyła pojedynczą linię przez TCP, działa tylko gdy drukarka nie drukuje.</div>
+    </div>
+
+    <div style="height:12px"></div>
+
     <!-- Jog / Pen / Steppers -->
     <div class="box">
       <div class="row" style="justify-content: space-between;">
@@ -230,6 +245,36 @@ <h1 style="margin:0;">artNC</h1>
         </div>
       </div>
     </div>
+
+    <div style="height:12px"></div>
+
+    <div class="box">
+      <div class="small">Symulator: aktualnie załadowane ACODE + podświetlenie linii</div>
+      <div class="preview-area" style="margin-top:10px;">
+        <img id="senderPrev" alt="preview" />
+        <canvas id="simCanvasSender" class="simCanvas"></canvas>
+      </div>
+      <div class="sim-controls">
+        <button class="btn" id="simPlaySender">Play</button>
+        <button class="btn" id="simPauseSender">Pause</button>
+        <button class="btn" id="simResetSender">Reset</button>
+
+        <span class="pill">Speed</span>
+        <input id="simSpeedSender" type="range" min="0.25" max="6" step="0.25" value="2">
+        <span class="pill mono" id="simSpeedValSender">2.00x</span>
+
+        <span class="pill">Frame</span>
+        <input id="simScrubSender" type="range" min="0" max="0" step="1" value="0">
+        <span class="pill mono" id="simPosSender">0/0</span>
+
+        <span class="pill">Sprite scale</span>
+        <input id="simSpriteScaleSender" type="range" min="0.10" max="1.00" step="0.05" value="0.35">
+        <span class="pill mono" id="simSpriteScaleValSender">0.35</span>
+
+        <span class="pill">wheelbase</span>
+        <span class="pill mono" id="simWheelbaseSender">-</span>
+      </div>
+    </div>
   </div>
 
   <!-- Generator PNG -->
@@ -603,6 +648,12 @@ <h1 style="margin:0;">artNC</h1>
 
 <script>
   const qs = (id) => document.getElementById(id);
+  const fmtSeconds = (s) => {
+    if (!isFinite(s) || s <= 0) return "-";
+    const m = Math.floor(s / 60);
+    const sec = Math.round(s % 60);
+    return `${m}m ${sec}s`;
+  };
 
   // Tabs
   document.querySelectorAll(".tab").forEach(btn => {
@@ -615,6 +666,7 @@ <h1 style="margin:0;">artNC</h1>
       requestAnimationFrame(() => {
         resizeSim("gen");
         resizeSim("text");
+        resizeSim("sender");
       });
     };
   });
@@ -654,17 +706,31 @@ <h1 style="margin:0;">artNC</h1>
     qs("error").textContent = "";
     qs("current").textContent = "";
     qs("lastok").textContent = "-";
+    qs("lastokline").textContent = "-";
     qs("progress").textContent = "0/" + out.lines;
+    qs("esttotal").textContent = fmtSeconds(out.est_seconds || 0);
+    qs("estremaining").textContent = fmtSeconds(out.est_seconds || 0);
+    qs("start_line").value = "1";
+    await loadSenderViz().catch(() => {});
   }
 
   qs("load").onclick = () => loadAcode().catch(e => qs("error").textContent = e.message);
-  qs("start").onclick = () => post("/api/start", new FormData()).catch(e => qs("error").textContent = e.message);
+  qs("start").onclick = () => {
+    const fd = new FormData();
+    fd.set("start", qs("start_line").value || "1");
+    post("/api/start", fd).catch(e => qs("error").textContent = e.message);
+  };
   qs("pause").onclick = () => post("/api/pause", new FormData()).catch(e => qs("error").textContent = e.message);
   qs("resume").onclick = () => post("/api/resume", new FormData()).catch(e => qs("error").textContent = e.message);
   qs("stop").onclick = () => post("/api/stop", new FormData()).catch(e => qs("error").textContent = e.message);
 
   // SSE
   const ev = new EventSource("/events");
+  const applyEst = (obj) => {
+    if (obj.est_seconds !== undefined) qs("esttotal").textContent = fmtSeconds(obj.est_seconds);
+    if (obj.est_remaining !== undefined) qs("estremaining").textContent = fmtSeconds(obj.est_remaining);
+    if (obj.last_ok_idx !== undefined) qs("lastokline").textContent = obj.last_ok_idx ? String(obj.last_ok_idx) : "-";
+  };
   ev.onmessage = (e) => {
     const data = JSON.parse(e.data);
 
@@ -675,9 +741,15 @@ <h1 style="margin:0;">artNC</h1>
         qs("error").textContent = "";
         qs("lastok").textContent = "";
         if (payload.total && payload.idx) qs("progress").textContent = payload.idx + "/" + payload.total;
+        if (payload.idx) simSender.gotoLine(payload.idx);
+      }
+      if (kind === "ok") {
+        qs("lastok").textContent = "OK";
+        if (payload.idx) qs("lastokline").textContent = payload.idx;
       }
-      if (kind === "ok") qs("lastok").textContent = "OK";
       if (kind === "error") qs("error").textContent = payload.msg;
+      if (kind === "status" && payload.msg) qs("runstate").textContent = payload.msg;
+      if (payload) applyEst(payload);
       return;
     }
 
@@ -686,6 +758,8 @@ <h1 style="margin:0;">artNC</h1>
     qs("progress").textContent = idx + "/" + total;
     if (data.error) qs("error").textContent = data.error;
     qs("runstate").textContent = data.paused ? "paused" : (data.running ? "running" : "idle");
+    if (idx) simSender.gotoLine(idx);
+    applyEst(data);
   };
 
   // Jog helpers
@@ -743,6 +817,15 @@ <h1 style="margin:0;">artNC</h1>
     post("/api/steppers", fd).catch(e => qs("jogerr").textContent = e.message);
   };
 
+  qs("manual_send").onclick = () => {
+    qs("error").textContent = "";
+    const fd = new FormData();
+    fd.set("host", qs("host").value.trim());
+    fd.set("port", qs("port").value.trim());
+    fd.set("cmd", qs("manual_cmd").value.trim());
+    post("/api/manual", fd).catch(e => qs("error").textContent = e.message);
+  };
+
   // ----------------------------
   // Simulator (two instances: gen + text)
   // ----------------------------
@@ -751,6 +834,8 @@ <h1 style="margin:0;">artNC</h1>
       points: [],
       bounds: null,
       wheelbase_mm: 120,
+      linePoints: [],
+      linesTotal: 0,
       invert_y: false,
       equal: false,
       idx: 0,
@@ -984,16 +1069,12 @@ <h1 style="margin:0;">artNC</h1>
       draw();
     }
 
-    async function loadData(genId) {
-      const resp = await fetch("/api/vizdata/" + genId);
-      const ct = (resp.headers.get("content-type") || "").toLowerCase();
-      const text = await resp.text();
-      if (!ct.includes("application/json")) throw new Error("vizdata non-JSON: " + text.slice(0, 200));
-      const data = JSON.parse(text);
-
+    function applyData(data) {
       sim.points = data.points || [];
       sim.bounds = data.bounds || null;
       sim.wheelbase_mm = (data.settings && data.settings.wheelbase_mm) ? data.settings.wheelbase_mm : 120;
+      sim.linePoints = data.line_points || [];
+      sim.linesTotal = sim.linePoints.length;
       sim.equal = (data.viz && data.viz.equal) ? true : false;
       sim.invert_y = (data.viz && data.viz.invert_y) ? true : false;
 
@@ -1019,6 +1100,15 @@ <h1 style="margin:0;">artNC</h1>
       reset();
     }
 
+    async function loadData(genId) {
+      const resp = await fetch("/api/vizdata/" + genId);
+      const ct = (resp.headers.get("content-type") || "").toLowerCase();
+      const text = await resp.text();
+      if (!ct.includes("application/json")) throw new Error("vizdata non-JSON: " + text.slice(0, 200));
+      const data = JSON.parse(text);
+      applyData(data);
+    }
+
     // wiring
     qs(playId).onclick = () => play();
     qs(pauseId).onclick = () => pause();
@@ -1042,10 +1132,27 @@ <h1 style="margin:0;">artNC</h1>
       draw();
     };
 
+    function gotoLine(lineIdx) {
+      if (!sim.points || sim.points.length === 0) return;
+      if (!lineIdx || lineIdx < 1) return;
+      let target = null;
+      if (sim.linePoints && sim.linePoints.length >= lineIdx) {
+        target = sim.linePoints[lineIdx - 1];
+      }
+      if (target === null || target === undefined) {
+        const fraction = (lineIdx - 1) / Math.max(1, sim.linesTotal || sim.points.length);
+        target = Math.floor(fraction * sim.points.length);
+      }
+      sim.idx = Math.max(0, Math.min(target, Math.max(0, sim.points.length - 1)));
+      qs(scrubId).value = String(sim.idx);
+      qs(posId).textContent = sim.idx + "/" + Math.max(0, sim.points.length - 1);
+      draw();
+    }
+
     img.onload = () => { resize(); draw(); };
     window.addEventListener("resize", () => resize());
 
-    return { loadData, resize, reset };
+    return { loadData, resize, reset, gotoLine, applyData, get lineCount() { return sim.linesTotal; } };
   }
 
   const simGen = makeSim(
@@ -1066,9 +1173,27 @@ <h1 style="margin:0;">artNC</h1>
     "simSpriteScaleText", "simSpriteScaleValText"
   );
 
+  const simSender = makeSim(
+    "sender",
+    "senderPrev", "simCanvasSender",
+    "simWheelbaseSender", "simPosSender", "simScrubSender",
+    "simPlaySender", "simPauseSender", "simResetSender",
+    "simSpeedSender", "simSpeedValSender",
+    "simSpriteScaleSender", "simSpriteScaleValSender"
+  );
+  qs("senderPrev").src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
+
+  async function loadSenderViz() {
+    const resp = await fetch("/api/vizdata/current");
+    if (!resp.ok) throw new Error("no viz for current");
+    const data = await resp.json();
+    simSender.applyData(data);
+  }
+
   function resizeSim(which) {
     if (which === "gen") simGen.resize();
     if (which === "text") simText.resize();
+    if (which === "sender") simSender.resize();
   }
 
   // ----------------------------
@@ -1137,6 +1262,9 @@ <h1 style="margin:0;">artNC</h1>
 
     qs("acode").value = "loaded from generator (" + out.lines + " lines)\n";
     qs("loaded").textContent = "loaded lines: " + out.lines;
+    qs("start_line").value = "1";
+    if (lastGenId) qs("senderPrev").src = "/preview/" + lastGenId + ".png?ts=" + Date.now();
+    await loadSenderViz().catch(() => {});
 
     document.querySelector('.tab[data-tab="sender"]').click();
   };
@@ -1248,6 +1376,9 @@ <h1 style="margin:0;">artNC</h1>
 
     qs("acode").value = "loaded from text outline (" + out.lines + " lines)\n";
     qs("loaded").textContent = "loaded lines: " + out.lines;
+    qs("start_line").value = "1";
+    if (lastTextId) qs("senderPrev").src = "/preview/" + lastTextId + ".png?ts=" + Date.now();
+    await loadSenderViz().catch(() => {});
 
     document.querySelector('.tab[data-tab="sender"]').click();
   };
diff --git a/ui_sender.py b/ui_sender.py
index 29f2756..862d404 100644
--- a/ui_sender.py
+++ b/ui_sender.py
@@ -45,6 +45,9 @@
 
 events = queue.Queue(maxsize=2000)
 
+W_RE = re.compile(r"^W\s+L(-?\d+)\s+R(-?\d+)\s+F(\d+)\s*$")
+P_RE = re.compile(r"^P\s+([UD])\s*$")
+
 def push_event(kind: str, payload: dict):
     msg = {"kind": kind, "payload": payload, "ts": time.time()}
     try:
@@ -68,9 +71,12 @@ class JobState:
     port: int = DEFAULT_PORT
     lines: Optional[List[str]] = None
     idx: int = 0
+    last_ok_idx: int = 0
     last_sent: str = ""
     last_ok: bool = False
     error: str = ""
+    line_secs: List[float] = None  # type: ignore[assignment]
+    total_est_s: float = 0.0
 
 state = JobState()
 state_lock = threading.Lock()
@@ -148,9 +154,10 @@ def sender_worker():
         host = state.host
         port = state.port
         lines = state.lines or []
-        state.idx = 0
+        state.idx = state.idx if state.idx < len(lines) else 0
         state.last_sent = ""
         state.last_ok = False
+        state.last_ok_idx = 0
         state.error = ""
         state.stopping = False
 
@@ -207,6 +214,8 @@ def sender_worker():
             ok = wait_ok(sock, LINE_ACK_TIMEOUT_S)
             with state_lock:
                 state.last_ok = ok
+                if ok:
+                    state.last_ok_idx = idx + 1
 
             if not ok:
                 with state_lock:
@@ -296,6 +305,75 @@ def _supports_arg(script_path: str, arg: str) -> bool:
     except OSError:
         return False
 
+# ----------------------------
+# Time estimate (mirrors print.py defaults)
+# ----------------------------
+def estimate_motion_seconds(
+    line: str,
+    feed_to_sps: float = 0.6,
+    min_sps: float = 50.0,
+    max_sps: float = 2500.0,
+    servo_settle_s: float = 0.18,
+    start_sps: float = 120.0,
+    accel_sps2: float = 8000.0,
+) -> float:
+    if line == "H":
+        return 0.25
+    if line == "END":
+        return 0.25
+    if line.startswith("E"):
+        return 0.25
+
+    if P_RE.match(line):
+        return servo_settle_s + 0.25
+
+    m = W_RE.match(line)
+    if not m:
+        return 0.6
+
+    l = abs(int(m.group(1)))
+    r = abs(int(m.group(2)))
+    f = int(m.group(3))
+    steps = max(l, r)
+    if steps <= 0:
+        return 0.25
+
+    v_target = f * feed_to_sps
+    if v_target < min_sps:
+        v_target = min_sps
+    if v_target > max_sps:
+        v_target = max_sps
+
+    v0 = start_sps
+    if v0 < min_sps:
+        v0 = min_sps
+    if v0 > v_target:
+        v0 = v_target
+
+    a = accel_sps2
+    if a < 1.0:
+        a = 1.0
+
+    ramp_steps = (v_target * v_target - v0 * v0) / (2.0 * a)
+    if ramp_steps < 0.0:
+        ramp_steps = 0.0
+
+    half = steps / 2.0
+    if ramp_steps > half:
+        ramp_steps = half
+
+    t_ramp = (v_target - v0) / a
+    if t_ramp < 0.0:
+        t_ramp = 0.0
+
+    cruise_steps = steps - 2.0 * ramp_steps
+    if cruise_steps < 0.0:
+        cruise_steps = 0.0
+
+    t_cruise = cruise_steps / v_target if v_target > 1e-9 else 9999.0
+
+    return (2.0 * t_ramp) + t_cruise + 0.30
+
 # ----------------------------
 # Settings parsing without importing acode.py
 # ----------------------------
@@ -381,6 +459,7 @@ def acode_to_trajectory(
     th = 0.0
     pen_down = True
     pts: List[Dict[str, float]] = [{"x": x, "y": y, "theta": th, "pen_down": pen_down}]
+    line_points: List[int] = []
 
     xmin = xmax = x
     ymin = ymax = y
@@ -397,8 +476,10 @@ def add_pt(px: float, py: float, pth: float, p_pen: bool):
     arc_step_mm = max(1e-6, arc_step_mm)
 
     for raw in lines:
+        line_points.append(len(pts) - 1)
         s = raw.strip()
         if not s:
+            add_pt(x, y, th, pen_down)
             continue
 
         if s == "H" and home_resets_pose:
@@ -459,6 +540,7 @@ def add_pt(px: float, py: float, pth: float, p_pen: bool):
     return {
         "points": pts,
         "bounds": {"xmin": xmin, "xmax": xmax, "ymin": ymin, "ymax": ymax},
+        "line_points": line_points,
         "settings": {
             "wheelbase_mm": wheelbase_mm,
             "steps_per_mm": steps_per_mm,
@@ -705,25 +787,31 @@ def api_load():
 
     lines = [ln.rstrip("\r\n") for ln in content.splitlines()]
     lines = [ln for ln in lines if ln.strip()]
+    line_secs = [estimate_motion_seconds(ln) for ln in lines]
 
     with state_lock:
         state.host = host
         state.port = port
         state.lines = lines
         state.idx = 0
+        state.last_ok_idx = 0
         state.error = ""
         state.last_sent = ""
         state.last_ok = False
+        state.line_secs = line_secs
+        state.total_est_s = sum(line_secs)
 
     push_event("status", {"msg": "loaded", "lines": len(lines)})
-    return jsonify({"ok": True, "lines": len(lines)})
+    return jsonify({"ok": True, "lines": len(lines), "est_seconds": state.total_est_s})
 
 @app.route("/api/start", methods=["POST"])
 def api_start():
     global worker_thread
+    start_idx = _safe_int("start", 1) - 1
     with state_lock:
         if not state.lines:
             return jsonify({"ok": False, "error": "no ACODE loaded"}), 400
+        state.idx = max(0, min(start_idx, len(state.lines) - 1))
         state.running = True
         state.paused = False
         state.stopping = False
@@ -761,6 +849,12 @@ def api_stop():
 
 @app.route("/events")
 def sse_events():
+    def _remaining():
+        with state_lock:
+            secs = state.line_secs or []
+            idx = state.idx
+        return float(sum(secs[idx:])) if secs else 0.0
+
     def gen():
         with state_lock:
             snap = {
@@ -770,12 +864,20 @@ def gen():
                 "total": len(state.lines or []),
                 "last_sent": state.last_sent,
                 "last_ok": state.last_ok,
+                "last_ok_idx": state.last_ok_idx,
                 "error": state.error,
+                "est_seconds": state.total_est_s,
+                "est_remaining": _remaining(),
             }
         yield "data: " + json.dumps(snap) + "\n\n"
 
         while True:
             msg = events.get()
+            if isinstance(msg, dict) and msg.get("kind") in {"line", "ok", "status", "done", "error"}:
+                msg.setdefault("payload", {})["est_remaining"] = _remaining()
+                with state_lock:
+                    msg["payload"]["est_seconds"] = state.total_est_s
+                    msg["payload"]["last_ok_idx"] = state.last_ok_idx
             yield "data: " + json.dumps(msg) + "\n\n"
 
     return Response(gen(), mimetype="text/event-stream")
@@ -872,6 +974,26 @@ def api_steppers():
     push_event("error", {"msg": out["error"] or "steppers failed"})
     return jsonify({"ok": False, "error": out["error"] or "steppers failed"}), 500
 
+@app.route("/api/manual", methods=["POST"])
+def api_manual():
+    err = _busy_guard()
+    if err:
+        return jsonify({"ok": False, "error": err}), 409
+
+    host = request.form.get("host", "").strip() or "192.168.4.1"
+    port = _safe_int("port", DEFAULT_PORT)
+    cmd = (request.form.get("cmd", "") or "").strip()
+    if not cmd:
+        return jsonify({"ok": False, "error": "missing cmd"}), 400
+
+    push_event("line", {"idx": 0, "total": 0, "line": cmd})
+    out = send_one_command(host, port, cmd, timeout_s=LINE_ACK_TIMEOUT_S)
+    if out["ok"]:
+        push_event("ok", {"idx": 0})
+        return jsonify({"ok": True, "line": cmd})
+    push_event("error", {"msg": out["error"] or "manual failed"})
+    return jsonify({"ok": False, "error": out["error"] or "manual failed"}), 500
+
 # ----------------------------
 # Generator: PNG
 # ----------------------------
@@ -1089,6 +1211,7 @@ def api_push_to_sender():
 
     lines = [ln.rstrip("\r\n") for ln in text.splitlines()]
     lines = [ln for ln in lines if ln.strip()]
+    line_secs = [estimate_motion_seconds(ln) for ln in lines]
 
     with state_lock:
         if host:
@@ -1100,9 +1223,12 @@ def api_push_to_sender():
                 pass
         state.lines = lines
         state.idx = 0
+        state.last_ok_idx = 0
         state.error = ""
         state.last_sent = ""
         state.last_ok = False
+        state.line_secs = line_secs
+        state.total_est_s = sum(line_secs)
 
     push_event("status", {"msg": "loaded_from_generator", "lines": len(lines)})
     return jsonify({"ok": True, "lines": len(lines)})
@@ -1142,5 +1268,25 @@ def api_vizdata(gen_id: str):
     traj["viz"] = {"equal": viz_equal, "invert_y": viz_invert_y}
     return jsonify(traj)
 
+@app.route("/api/vizdata/current", methods=["GET"])
+def api_vizdata_current():
+    with state_lock:
+        current_lines = list(state.lines or [])
+    if not current_lines:
+        abort(404)
+
+    machine = resolve_machine_settings(ACODE_PY_PATH)
+    traj = acode_to_trajectory(
+        lines=current_lines,
+        wheelbase_mm=machine["wheelbase_mm"],
+        steps_per_mm=machine["steps_per_mm"],
+        turn_gain=machine["turn_gain"],
+        arc_step_mm=1.0,
+        arc_step_deg=1.0,
+        home_resets_pose=True,
+    )
+    traj["viz"] = {"equal": False, "invert_y": False}
+    return jsonify(traj)
+
 if __name__ == "__main__":
     app.run(host="127.0.0.1", port=5000, debug=False, threaded=True)