From 800eff05a6a658044cf7ceec2ddc682436ba73d5 Mon Sep 17 00:00:00 2001
From: Adrian Conlon <Adrian.conlon@gmail.com>
Date: Fri, 26 Jul 2019 00:58:54 +0100
Subject: [PATCH] Correct AF value in LR35902 emulator

Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>
---
 LR35902/LR35902.cs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/LR35902/LR35902.cs b/LR35902/LR35902.cs
index 9068642..8604507 100644
--- a/LR35902/LR35902.cs
+++ b/LR35902/LR35902.cs
@@ -11,6 +11,7 @@ namespace EightBit
         public class LR35902 : IntelProcessor
         {
             private readonly Bus bus;
+            private readonly Register16 af = new Register16((int)Mask.Mask16);
             private bool prefixCB = false;
 
             public LR35902(Bus bus)
@@ -22,7 +23,14 @@ namespace EightBit
 
             public int ClockCycles => this.Cycles * 4;
 
-            public override Register16 AF { get; } = new Register16((int)Mask.Mask16);
+            public override Register16 AF
+            {
+                get
+                {
+                    this.af.Low = (byte)HigherNibble(this.af.Low);
+                    return this.af;
+                }
+            }
 
             public override Register16 BC { get; } = new Register16((int)Mask.Mask16);