diff --git a/lib/logger.cc b/lib/logger.cc
index 3bfd61b1..be3ea3d0 100644
--- a/lib/logger.cc
+++ b/lib/logger.cc
@@ -31,11 +31,12 @@ std::string Logger::toString(const AnyLogMessage& message)
 {
     std::stringstream stream;
 
-	auto indent = [&]() {
-		if (!indented)
-			stream << "      ";
-		indented = false;
-	};
+    auto indent = [&]()
+    {
+        if (!indented)
+            stream << "      ";
+        indented = false;
+    };
 
     std::visit(
         overloaded{
@@ -58,7 +59,7 @@ std::string Logger::toString(const AnyLogMessage& message)
                     60e9 / m.rotationalPeriod);
             },
 
-			/* Indicates that we're starting a write operation. */
+            /* Indicates that we're starting a write operation. */
             [&](const BeginWriteOperationLogMessage& m)
             {
                 stream << fmt::format("{:2}.{}: ", m.cylinder, m.head);
@@ -72,10 +73,11 @@ std::string Logger::toString(const AnyLogMessage& message)
                 indented = true;
             },
 
-            /* We've just read a track (we might reread it if there are errors) */
+            /* We've just read a track (we might reread it if there are errors)
+             */
             [&](const TrackReadLogMessage& m)
             {
-				const auto& track = *m.track;
+                const auto& track = *m.track;
                 const auto& trackdataflux = track.trackDatas.end()[-1];
 
                 indent();
@@ -98,13 +100,8 @@ std::string Logger::toString(const AnyLogMessage& message)
 
                 std::vector<std::shared_ptr<const Sector>> sectors(
                     track.sectors.begin(), track.sectors.end());
-                std::sort(sectors.begin(),
-                    sectors.end(),
-                    [](const std::shared_ptr<const Sector>& s1,
-                        const std::shared_ptr<const Sector>& s2)
-                    {
-                        return s1->logicalSector < s2->logicalSector;
-                    });
+                std::sort(
+                    sectors.begin(), sectors.end(), sectorPointerSortPredicate);
 
                 for (const auto& sector : sectors)
                     stream << fmt::format(" {}{}",
diff --git a/lib/reader.cc b/lib/reader.cc
index a5254c2b..5afbf53d 100644
--- a/lib/reader.cc
+++ b/lib/reader.cc
@@ -99,6 +99,8 @@ std::shared_ptr<const DiskFlux> readDiskCommand(FluxSource& fluxsource, Abstract
 			testForEmergencyStop();
 
             auto track = std::make_shared<TrackFlux>();
+			track->physicalCylinder = cylinder;
+			track->physicalHead = head;
 			diskflux->tracks.push_back(track);
 
             std::set<std::shared_ptr<const Sector>> track_sectors;
diff --git a/src/gui/visualisation.cc b/src/gui/visualisation.cc
index a44209f5..4ad3a376 100644
--- a/src/gui/visualisation.cc
+++ b/src/gui/visualisation.cc
@@ -2,6 +2,7 @@
 #include "visualisation.h"
 #include "fluxmap.h"
 #include "flux.h"
+#include "sector.h"
 #include "fmt/format.h"
 #include <wx/wx.h>
 
@@ -69,15 +70,43 @@ void VisualisationControl::OnPaint(wxPaintEvent&)
 		);
 	}
 
-	dc.SetBrush(DARK_GREY_BRUSH);
-	dc.SetPen(DARK_GREY_PEN);
 	for (int track = 0; track <= TRACKS; track++)
 	{
 		int y = scaletop + track*SECTORSIZE;
+		dc.SetBrush(DARK_GREY_BRUSH);
+		dc.SetPen(DARK_GREY_PEN);
 		dc.DrawRectangle(
 			{ w2-TICK/2, y },
 			{ TICK, SECTORSIZE-1 }
 		);
+
+		auto drawSectors =
+			[&](int head) {
+				key_t key = { track, head };
+				std::vector<std::shared_ptr<const Sector>> sectors;
+				for (auto it = _sectors.lower_bound(key); it != _sectors.upper_bound(key); it++)
+					sectors.push_back(it->second);
+				std::sort(sectors.begin(), sectors.end(), sectorPointerSortPredicate);
+
+				int x = 1;
+				for (const auto& sector : sectors)
+				{
+					if (head == 0)
+						dc.DrawRectangle(
+							{ w2 - x*SECTORSIZE - (SECTORSIZE-1), y },
+							{ SECTORSIZE-1, SECTORSIZE-1 }
+						);
+					else
+						dc.DrawRectangle(
+							{ w2 + x*SECTORSIZE, y },
+							{ SECTORSIZE-1, SECTORSIZE-1 }
+						);
+					x++;
+				}
+			};
+
+		drawSectors(0);
+		drawSectors(1);
 	}
 }
 
@@ -97,6 +126,11 @@ void VisualisationControl::Clear()
 
 void VisualisationControl::SetTrackData(std::shared_ptr<const TrackFlux> track)
 {
+	key_t key = { track->physicalCylinder, track->physicalHead };
+	_sectors.erase(key);
+	for (auto& sector : track->sectors)
+		_sectors.insert({ key, sector });
+
 	Refresh();
 }