Update FINLOG

src/basic/math/bd7e.FINLOG.s

@@ -3,17 +3,24 @@
 ;; #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 - add an ASCII digit in A that has been converted to a signed integer to FAC1
 ;
+; This is verified to be identical to the original Microsoft implementation where it was named FINLOG.
+;
 ; See also:
 ; - [CM64] Computes Mapping the Commodore 64 - page 113
 ;
 
 FINLOG:
-    pha
-    jsr mov_FAC1_FAC2
-    pla
-    jsr convert_A_to_FAC1
-    jsr add_FAC2_FAC1
-    rts
+        pha
+        jsr mov_r_FAC1_FAC2
+        pla
+        jsr convert_A_to_FAC1
+        lda FAC2_sign
+        eor FAC1_sign
+        sta ARISGN                  ; Resultant sign
+        ldx FAC1_exponent           ; Set signs on thing to add
+        jmp add_FAC2_FAC1