From 998b64d14c9d055562d8c1611813d40af4cb030b Mon Sep 17 00:00:00 2001
From: Ian C <ianc@noddybox.co.uk>
Date: Fri, 9 Mar 2012 23:01:13 +0000
Subject: Further bug fixes to Z80.  Now starts the Spectrum ROM OK.

---
 .../Z80CpuDecodeByte.cs                            | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

(limited to 'src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs')

diff --git a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
index 22a6c98..63ccc15 100644
--- a/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
+++ b/src/Noddybox.Emulation.EightBit.Z80/Z80CpuDecodeByte.cs
@@ -349,7 +349,14 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0x36:  // LD (HL),n
-                    clock.Add(10);
+                    if (shift == 0xdd || shift == 0xfd)
+                    {
+                        clock.Add(7);
+                    }
+                    else
+                    {
+                        clock.Add(10);
+                    }
                     addr = (ushort)(hl.reg + Offset());
                     memory.Write(addr, memory.Read(PC++));
                     break;
@@ -1093,7 +1100,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0xc5:  // PUSH BC
-                    clock.Add(10);
+                    clock.Add(11);
                     PUSH(BC.reg);
                     break;
 
@@ -1112,7 +1119,7 @@ namespace Noddybox.Emulation.EightBit.Z80
 
                 case 0xc9:  // RET
                     clock.Add(10);
-                    SP = POP();
+                    PC = POP();
                     break;
 
                 case 0xca:  // JP Z,nnnn
@@ -1120,8 +1127,6 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0xcb:  // CB shift
-                    AddR(1);
-
                     // Check for IX/IY shift
                     //
                     if (shift != 0)
@@ -1139,6 +1144,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     }
                     else
                     {
+                        AddR(1);
                         DecodeCB(memory.Read(PC++));
                     }
                     break;
@@ -1186,7 +1192,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0xd5:  // PUSH DE
-                    clock.Add(10);
+                    clock.Add(11);
                     PUSH(DE.reg);
                     break;
 
@@ -1266,7 +1272,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0xe5:  // PUSH HL
-                    clock.Add(10);
+                    clock.Add(11);
                     PUSH(hl.reg);
                     break;
 
@@ -1341,7 +1347,7 @@ namespace Noddybox.Emulation.EightBit.Z80
                     break;
 
                 case 0xf5:  // PUSH AF
-                    clock.Add(10);
+                    clock.Add(11);
                     PUSH((ushort)((A << 8) | (int)(F)));
                     break;
 
-- 
cgit v1.3