diff --git a/src/basic/math_consts/e2ea.const_QUARTER.s b/src/basic/math_consts/e2ea.const_QUARTER.s
index 3cba4c8b..e802a089 100644
--- a/src/basic/math_consts/e2ea.const_QUARTER.s
+++ b/src/basic/math_consts/e2ea.const_QUARTER.s
@@ -2,8 +2,13 @@
 ;; #LAYOUT# *   BASIC_0 #TAKE
 ;; #LAYOUT# *   *       #IGNORE
 
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
+; Math package - 1/4
+;
+; This is verified to be identical to the original Microsoft implementation where it was named FR4.
 ;
-; Math package - a constant, for documentation see:
 ; - https://sourceforge.net/p/acme-crossass/code-0/38/tree/trunk/ACME_Lib/cbm/c64/float.a?force=True
 ;
 
diff --git a/tools/similarity.c b/tools/similarity.c
index 848aaf2d..d0f9acf9 100644
--- a/tools/similarity.c
+++ b/tools/similarity.c
@@ -20,7 +20,7 @@ int matches[MAX_SIZE];
 
 int phase_mask[MAX_SIZE+MAX_SIZE];
 
-#define NUM_CHUNKS 12
+#define NUM_CHUNKS 11
 // Pairs of start, end memory addresses of known exact similarity with the open source Microsoft BASIC
 unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
     0xB391, 0xB39D,
@@ -33,8 +33,7 @@ unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
     0xBDDD, 0xBF51,
     0xBFB4, 0xBFEC,
     0xE264, 0xE2C2,     // Two byte gap here is an optimization
-    0xE2C5, 0xE2E9,
-    0xE2EF, 0xE37A,
+    0xE2C5, 0xE37A,
 };