diff --git a/src/VRio.App/MainForm.cs b/src/VRio.App/MainForm.cs
index 8f2b967..a3c52a8 100644
--- a/src/VRio.App/MainForm.cs
+++ b/src/VRio.App/MainForm.cs
@@ -148,6 +148,7 @@ internal sealed class MainForm : Form
         // Canvas ↔ device wiring.
         _canvas.LampProvider = _device.GetLamp;
         _canvas.AxisProvider = _device.GetAxis;
+        _canvas.WireAxisProvider = _device.GetWireAxis;
         _canvas.AddressPressed += _device.PressAddress;
         _canvas.AddressReleased += _device.ReleaseAddress;
         _canvas.AxisMoved += (axis, value) => _device.SetAxis(axis, value);
@@ -192,7 +193,11 @@ internal sealed class MainForm : Form
             if (!_kbInput.Checked)
                 _router.ReleaseAllKeys();
         };
-        _invertY.CheckedChanged += (_, _) => _device.InvertJoystickY = _invertY.Checked;
+        _invertY.CheckedChanged += (_, _) =>
+        {
+            _device.InvertJoystickY = _invertY.Checked;
+            _canvas.Invalidate(); // the wire readout flips even though the axes didn't move
+        };
         _device.InvertJoystickY = _invertY.Checked; // the field initializer raises no event
         _kbLights.CheckedChanged += (_, _) =>
         {
diff --git a/src/VRio.App/PanelCanvas.cs b/src/VRio.App/PanelCanvas.cs
index 5c4fdbf..b17a99b 100644
--- a/src/VRio.App/PanelCanvas.cs
+++ b/src/VRio.App/PanelCanvas.cs
@@ -73,6 +73,12 @@ internal sealed class PanelCanvas : Control
     /// <summary>Current raw value of an axis (from the device).</summary>
     public Func<RioAxis, short>? AxisProvider { get; set; }
 
+    /// <summary>
+    /// Axis value as transmitted to the host (joystick Y sign flip applied).
+    /// The text readout shows this; the dot and gauges track physical state.
+    /// </summary>
+    public Func<RioAxis, short>? WireAxisProvider { get; set; }
+
     /// <summary>The user pressed a panel control.</summary>
     public event Action<int>? AddressPressed;
 
@@ -299,9 +305,10 @@ internal sealed class PanelCanvas : Control
                     new Size(statusRect.Width, 0), TextFormatFlags.WordBreak).Height + 2;
             }
 
+            short WireAxis(RioAxis a) => WireAxisProvider?.Invoke(a) ?? Axis(a);
             string readout =
-                $"Z {Axis(RioAxis.Throttle),4}  L {Axis(RioAxis.LeftPedal),3}  R {Axis(RioAxis.RightPedal),3}  " +
-                $"X {Axis(RioAxis.JoystickX),3}  Y {Axis(RioAxis.JoystickY),3}";
+                $"Z {WireAxis(RioAxis.Throttle),4}  L {WireAxis(RioAxis.LeftPedal),3}  R {WireAxis(RioAxis.RightPedal),3}  " +
+                $"X {WireAxis(RioAxis.JoystickX),3}  Y {WireAxis(RioAxis.JoystickY),3}";
             TextRenderer.DrawText(g, readout, statusFont,
                 new Rectangle(statusRect.X, readoutTop, statusRect.Width, statusRect.Bottom - readoutTop), green,
                 TextFormatFlags.Left | TextFormatFlags.Top | TextFormatFlags.SingleLine);
diff --git a/src/VRio.Core/Device/VRioDevice.cs b/src/VRio.Core/Device/VRioDevice.cs
index f169a19..c9994a6 100644
--- a/src/VRio.Core/Device/VRioDevice.cs
+++ b/src/VRio.Core/Device/VRioDevice.cs
@@ -108,6 +108,20 @@ public sealed class VRioDevice
         lock (_gate) return _axes[(int)axis];
     }
 
+    /// <summary>
+    /// Axis value as the next AnalogReply will carry it — same as
+    /// <see cref="GetAxis"/> except for the <see cref="InvertJoystickY"/> flip.
+    /// </summary>
+    public short GetWireAxis(RioAxis axis)
+    {
+        short value = GetAxis(axis);
+        return axis == RioAxis.JoystickY ? WireY(value) : value;
+    }
+
+    private short WireY(short y) => InvertJoystickY
+        ? (short)Math.Min(AnalogCodec.Max, -y) // clamp: -Min (8192) is one past the 14-bit Max
+        : y;
+
     /// <summary>
     /// Move an axis. Values are clamped to the 14-bit signed range the wire
     /// can carry; the new value is returned by the next AnalogReply.
@@ -281,9 +295,7 @@ public sealed class VRioDevice
                     y = _axes[(int)RioAxis.JoystickY];
                     x = _axes[(int)RioAxis.JoystickX];
                 }
-                if (InvertJoystickY) // clamp: -Min (8192) is one past the 14-bit Max
-                    y = (short)Math.Min(AnalogCodec.Max, -y);
-                Send(PacketBuilder.AnalogReply(t, l, r, y, x));
+                Send(PacketBuilder.AnalogReply(t, l, r, WireY(y), x));
                 break;
 
             case RioCommand.ResetRequest:
diff --git a/tests/VRio.Core.Tests/VRioDeviceTests.cs b/tests/VRio.Core.Tests/VRioDeviceTests.cs
index 38a17c9..c810c12 100644
--- a/tests/VRio.Core.Tests/VRioDeviceTests.cs
+++ b/tests/VRio.Core.Tests/VRioDeviceTests.cs
@@ -77,7 +77,8 @@ public class VRioDeviceTests
 
         byte[] p = Assert.Single(wire.Packets).Payload;
         Assert.Equal(-3000, AnalogCodec.Combine(p[6], p[7]));
-        Assert.Equal(3000, device.GetAxis(RioAxis.JoystickY)); // the panel's view is unflipped
+        Assert.Equal(3000, device.GetAxis(RioAxis.JoystickY));      // the panel's dot is unflipped
+        Assert.Equal(-3000, device.GetWireAxis(RioAxis.JoystickY)); // the panel's readout matches the wire
 
         // Full negative deflection: -Min is one past Max, so it clamps rather than throws.
         device.SetAxis(RioAxis.JoystickY, AnalogCodec.Min);