From 4ecb247c170569b7046e2b0c686d0b63d5317203 Mon Sep 17 00:00:00 2001
From: Asnivor <coding@asnitech.co.uk>
Date: Fri, 16 Mar 2018 08:08:35 +0000
Subject: [PATCH] Fixed AY-3-8912 overflow bug

---
 .../Hardware/SoundOuput/AYChip.cs             | 36 +++++++++----------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/SoundOuput/AYChip.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/SoundOuput/AYChip.cs
index 06817afe19..34515cd5eb 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/SoundOuput/AYChip.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/SoundOuput/AYChip.cs
@@ -650,32 +650,32 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                         _countE = 0;
                         _eState += +_eDirection;
 
-                        var mask = (1 << _registers[AY_E_SHAPE]);
-
                         if ((_eState & ~31) != 0)
                         {
+                            var mask = (1 << _registers[AY_E_SHAPE]);
+
                             if ((mask & ((1 << 0) | (1 << 1) | (1 << 2) | 
                                 (1 << 3) | (1 << 4) | (1 << 5) | (1 << 6) | 
                                 (1 << 7) | (1 << 9) | (1 << 15))) != 0)
                             {
                                 _eState = _eDirection = 0;
                             }
-                        }
-                        else if ((mask & ((1 << 8) | (1 << 12))) != 0)
-                        {
-                            _eState &= 31;
-                        }
-                        else if ((mask & ((1 << 10) | (1 << 14))) != 0)
-                        {
-                            _eDirection = -_eDirection;
-                            _eState += _eDirection;
-                        }
-                        else
-                        {
-                            // 11,13
-                            _eState = 31;
-                            _eDirection = 0;
-                        }
+                            else if ((mask & ((1 << 8) | (1 << 12))) != 0)
+                            {
+                                _eState &= 31;
+                            }
+                            else if ((mask & ((1 << 10) | (1 << 14))) != 0)
+                            {
+                                _eDirection = -_eDirection;
+                                _eState += _eDirection;
+                            }
+                            else
+                            {
+                                // 11,13
+                                _eState = 31;
+                                _eDirection = 0;
+                            }
+                        }                        
                     }
                 }