Add exp_FAC1

Had to deactivate it for MEGA65 because of conflicting code also placed at e000

tools/similarity.c

@@ -32,8 +32,8 @@ unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
     0xB983, 0xBDC1,
     0xBDDD, 0xBF51,
     0xBF71, 0xBF7A,
-    0xBFB4, 0xBFEC,
-    0xE043, 0xE08C,
+    0xBFB4, 0xBFFF,
+    0xE000, 0xE08C,
     0xE264, 0xE2C2,     // Two byte gap here is an optimization
     0xE2C5, 0xE37A,
 };