diff --git a/c64/btree.asm b/c64/btree.asm
index 56e096e..1325ee3 100644
--- a/c64/btree.asm
+++ b/c64/btree.asm
@@ -1,8 +1,21 @@
 // vim: filetype=kickass
 
+tree_clear:
+    lda #0
+    tay
+
+    !loop:
+        sta tree_values_lo, y
+        sta tree_values_hi, y
+        sta tree_left, y
+        sta tree_right, y
+        iny
+        bne !loop-
+
+    rts
+
 .const next_index = $02
 .const input = $03
-// NOTE Assumes the tree is zeroed
 tree_insert:
     ldx #0
 
@@ -93,14 +106,3 @@ tree_contains:
             rts
 
     brk
-
-
-    .align $100
-tree_values_lo:
-    .fill 256, 0
-tree_values_hi:
-    .fill 256, 0
-tree_left:
-    .fill 256, 0
-tree_right:
-    .fill 256, 0
diff --git a/c64/main.asm b/c64/main.asm
index dc37dba..f97c9db 100644
--- a/c64/main.asm
+++ b/c64/main.asm
@@ -126,6 +126,7 @@ main:
     sta $01
 
     jsr generate_multiplication_tables
+    jsr tree_clear
     //jsr test_tree
 
 
@@ -145,14 +146,3 @@ day01_input:
     .import text "../rust/inputs/day01"
     .byte 0
 
-    .align $100
-* = * "Square table"
-square1_lo:
-    .fill 512, 0
-square1_hi:
-    .fill 512, 0
-square2_lo:
-    .fill 512, 0
-square2_hi:
-    .fill 512, 0
-
diff --git a/c64/math.inc b/c64/math.inc
index a92df1a..05e2890 100644
--- a/c64/math.inc
+++ b/c64/math.inc
@@ -1,4 +1,14 @@
 // vim: filetype=kickass
+.const square1_lo = $c000
+.const square1_hi = $c200
+.const square2_lo = $c400
+.const square2_hi = $c600
+
+.const tree_values_lo = $c900
+.const tree_values_hi = $ca00
+.const tree_left = $cb00
+.const tree_right = $cc00
+
 .const udivmod32_dividend = $10 // 11,12,13
 .const udivmod32_divisor = $14 // 15,16,17
 .const udivmod32_result = $18 // 19,1a,1b