diff --git a/lib/TerranVirtualDisk-src.jar b/lib/TerranVirtualDisk-src.jar
index c09865f..bdc865e 100644
Binary files a/lib/TerranVirtualDisk-src.jar and b/lib/TerranVirtualDisk-src.jar differ
diff --git a/lib/TerranVirtualDisk.jar b/lib/TerranVirtualDisk.jar
index 9e592a5..a3de12f 100644
Binary files a/lib/TerranVirtualDisk.jar and b/lib/TerranVirtualDisk.jar differ
diff --git a/tsvm_core/src/net/torvald/tsvm/peripheral/TevdDiskDrive.kt b/tsvm_core/src/net/torvald/tsvm/peripheral/TevdDiskDrive.kt
index 4cc362b..a557472 100644
--- a/tsvm_core/src/net/torvald/tsvm/peripheral/TevdDiskDrive.kt
+++ b/tsvm_core/src/net/torvald/tsvm/peripheral/TevdDiskDrive.kt
@@ -445,7 +445,7 @@ class TevdDiskDrive(private val vm: VM, private val driveNum: Int, theTevdPath:
                 statusCode.set(STATE_CODE_STANDBY)
             }
             else if (inputString.startsWith("USAGE")) {
-                recipient?.writeout(composePositiveAns("USED123456/TOTAL654321"))
+                recipient?.writeout(composePositiveAns("USED${DOM.usedSpace}/TOTAL${DOM.totalSpace}"))
                 statusCode.set(STATE_CODE_STANDBY)
             }
             else
diff --git a/tsvm_executable/src/net/torvald/tsvm/TevdMenu.kt b/tsvm_executable/src/net/torvald/tsvm/TevdMenu.kt
index 077cfc0..7bc2e23 100644
--- a/tsvm_executable/src/net/torvald/tsvm/TevdMenu.kt
+++ b/tsvm_executable/src/net/torvald/tsvm/TevdMenu.kt
@@ -3,16 +3,23 @@ package net.torvald.tsvm
 import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import net.torvald.reflection.extortField
-import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.EntryID
-import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.PartialDOM
+import net.torvald.reflection.forceInvoke
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.DiskSkimmer.Companion.read
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.archivers.ClusteredFormatDOM
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.archivers.seekToCluster
+import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.toUint
 import net.torvald.tsvm.VMEmuExecutableWrapper.Companion.FONT
 import net.torvald.tsvm.peripheral.TevdDiskDrive
+import java.io.RandomAccessFile
 
 /**
  * Created by minjaesong on 2023-03-25.
  */
 class TevdMenu(parent: VMEmuExecutable, x: Int, y: Int, w: Int, h: Int) : EmuMenu(parent, x, y, w, h) {
 
+
+    private val devHasHook = HashSet<TevdDiskDrive>()
+
     override fun show() {
     }
 
@@ -22,18 +29,43 @@ class TevdMenu(parent: VMEmuExecutable, x: Int, y: Int, w: Int, h: Int) : EmuMen
     override fun update() {
     }
 
+    private fun setupHook(dev: TevdDiskDrive, batch: SpriteBatch) {
+        if (!devHasHook.contains(dev)) {
+            devHasHook.add(dev)
+
+            val DOM = dev.extortField<ClusteredFormatDOM>("DOM")!!
+            val ARCHIVE = DOM.extortField<RandomAccessFile>("ARCHIVE")!!
+
+            // this fails due to two reasons:
+            // 1. vm context is not GL context
+            // 2. probing at the disk during read/write operation corrupts shits
+            /*DOM.diskModifiedHook = {
+                val batchInUse = batch.isDrawing
+                if (!batchInUse) batch.begin()
+                rebuildClustmap(batch, DOM, ARCHIVE, 12, 12 + 13 * 3 + btnGap)
+                if (!batchInUse) batch.end()
+            }*/
+
+        }
+    }
+
     override fun render(batch: SpriteBatch) {
 
         val dev = parent.currentlyPersistentVM?.vm?.getIO()?.blockTransferPorts?.getOrNull(cardIndex ?: -1)?.recipient
 
+
         if (dev?.javaClass?.simpleName == "TevdDiskDrive") {
             val dev = dev as TevdDiskDrive
-            val DOM = dev.extortField<PartialDOM>("DOM")
+            val DOM = dev.extortField<ClusteredFormatDOM>("DOM")!!
+            val ARCHIVE = DOM.extortField<RandomAccessFile>("ARCHIVE")!!
+
+            setupHook(dev, batch)
 
             batch.inUse {
                 batch.color = Color.WHITE
                 FONT.draw(batch, "Disk UUID: ${dev.diskUUIDstr}", 12f, 12f)
-
+                FONT.draw(batch, "Used: ${DOM.usedClusterCount}/${DOM.totalClusterCount} Clusters", 12f, 12f + 13*1)
+                FONT.draw(batch, "Cluster Map:", 12f, 12f + 13*2)
 
             }
         }
@@ -47,6 +79,69 @@ class TevdMenu(parent: VMEmuExecutable, x: Int, y: Int, w: Int, h: Int) : EmuMen
 
     }
 
+
+    private val buttonColourFree = Color(0xfafafaff.toInt())
+    private val buttonColourOccupied = listOf(
+        4086 to Color(0xff0d89ff.toInt()),
+        3269 to Color(0xff5899ff.toInt()),
+        2452 to Color(0xff7daaff.toInt()),
+        1635 to Color(0xff9bbaff.toInt()),
+        818 to Color(0xffb6cbff.toInt()),
+        1 to Color(0xfed0dcff.toInt()),
+    )
+    private fun contentsSizeToButtonColour(i: Int): Color {
+        for (kv in buttonColourOccupied) {
+            if (i >= kv.first) return kv.second
+        }
+        return buttonColourFree
+    }
+
+    private val buttonColourFAT = Color(0x6cee91ff.toInt())
+    private val buttonColourFATdata = Color(0xf6cb07ff.toInt())
+    private val buttonColourReserved = Color(0x12adffff.toInt())
+    private val buttonColourVirtual = Color(0xece8d9ff.toInt())
+
+    private var btnW = 12
+    private var btnH = 12
+    private var btnGap = 2
+
+
+    private fun rebuildClustmap(batch: SpriteBatch, vdisk: ClusteredFormatDOM, ARCHIVE: RandomAccessFile, paintX: Int, paintY: Int) {
+        val fatClusterCount = vdisk.extortField<Int>("fatClusterCount")!!
+
+        vdisk?.let { vdisk ->
+            for (i in 0 until vdisk.totalClusterCount) {
+                val buttonCol = if (i in 0..1) buttonColourReserved
+                else if (i < fatClusterCount!! + 2) {
+                    ARCHIVE.seekToCluster(i)
+                    var dataFats = 0
+                    for (k in 0 until ClusteredFormatDOM.CLUSTER_SIZE step ClusteredFormatDOM.FAT_ENTRY_SIZE) {
+                        if (ARCHIVE.read(ClusteredFormatDOM.FAT_ENTRY_SIZE).toInt24() >= ClusteredFormatDOM.INLINE_FILE_CLUSTER_BASE) dataFats += 1
+                    }
+                    buttonColourFAT.cpy().lerp(buttonColourFATdata, dataFats.toFloat() / ClusteredFormatDOM.FATS_PER_CLUSTER)
+                }
+                else if (i >= ARCHIVE.length() / ClusteredFormatDOM.CLUSTER_SIZE) buttonColourVirtual
+                else {
+                    contentsSizeToButtonColour(vdisk.contentSizeInThisCluster(i))
+                }
+
+                // do something with buttonCol
+                val x = paintX + (i / 20) * (btnW + btnGap)
+                val y = paintY + (i % 20) * (btnH + btnGap)
+                batch.color = buttonCol
+                batch.fillRect(x, y, btnW, btnH)
+
+            }
+        }
+    }
+
+    private fun ByteArray.toInt24(offset: Int = 0): Int {
+        return  this[0 + offset].toUint().shl(16) or
+                this[1 + offset].toUint().shl(8) or
+                this[2 + offset].toUint()
+    }
+
+
     override fun dispose() {
     }
 }
\ No newline at end of file