From 922c881a232a41b6b2da8807ba052722a8c196fd Mon Sep 17 00:00:00 2001
From: FeralChild64 <you@example.com>
Date: Sat, 21 Mar 2020 16:14:38 +0100
Subject: [PATCH] fix for exponent manipulation during division

---
 c64/basic/math/bb12.div_FAC2_FAC1.s | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/c64/basic/math/bb12.div_FAC2_FAC1.s b/c64/basic/math/bb12.div_FAC2_FAC1.s
index 583572dc..77b1d61f 100644
--- a/c64/basic/math/bb12.div_FAC2_FAC1.s
+++ b/c64/basic/math/bb12.div_FAC2_FAC1.s
@@ -44,26 +44,24 @@ div_FAC2_FAC1:
 
 	// Subtract the exponents
 
-	lda #$80                            // correction for bias
+	lda #$62                            // correction for bias and FAC2 digits
 	sta RESHO+0
 	lda #$00
 	sta RESHO+1
 
-	lda FAC2_exponent
+	lda FAC2_exponent                   // add FAC2 exponent to temporary variable 
 	jsr muldiv_RESHO_01_add_A
 
-	lda RESHO+0
-	sec
-	sbc FAC1_exponent
-	sta RESHO+0
-	bcs !+
+    lda RESHO+0                         // subtract FAC1 exponent from temporary variable
+    sec
+    sbc FAC1_exponent
+    sta RESHO+0
+    bcs !+
+    dec RESHO+1
+ !:
 
-	lda RESHO+1
-	sbc #$00
-	sta RESHO+1
-	bcc_16 set_FAC1_zero               // result too low, set 0 and quit
-!:
-	bne_16 set_FAC1_max                // overflow
+    lda RESHO+1
+    bmi_16 set_FAC1_zero                // result too low, set 0 and quit
 
 	lda RESHO+0
 	sta FAC1_exponent
@@ -71,6 +69,7 @@ div_FAC2_FAC1:
 	// Divide the mantissas
 
 	jsr div_FAC1_denorm
+
 	jsr muldiv_RESHO_set_0
 	jsr div_mantissas