From c61a15458cc1bdfc73c63b87d43252d73adfb4aa Mon Sep 17 00:00:00 2001
From: alyosha-tas <alexei.f.k@gmail.com>
Date: Tue, 27 Dec 2016 09:50:14 -0500
Subject: [PATCH] Intellivision more cleanup

---
 .../Consoles/Intellivision/PSG.cs             | 19 +----
 .../Consoles/Intellivision/STIC.cs            | 85 +++++++------------
 2 files changed, 32 insertions(+), 72 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Intellivision/PSG.cs b/BizHawk.Emulation.Cores/Consoles/Intellivision/PSG.cs
index 17293c36ed..0716bd0141 100644
--- a/BizHawk.Emulation.Cores/Consoles/Intellivision/PSG.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Intellivision/PSG.cs
@@ -5,7 +5,6 @@ using BizHawk.Emulation.Common;
 
 namespace BizHawk.Emulation.Cores.Intellivision
 {
-	// Sound refactor todo: Implement ISoundProvider, and register _psg in the Intellivision core
 	public sealed class PSG : ISoundProvider
 	{
 		public ushort[] Register = new ushort[16];
@@ -66,19 +65,15 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			for (int i = 0; i < samples.Length / 2; i++)
 			{
 				samples[i * 2] = (short)(audio_samples[(int)Math.Floor(3.7904 * i)]);
-				//samples[i * 2] = (short)(audio_samples[(int)Math.Floor(4.0 * i)]);
-				//samples[i * 2] = (short)(audio_samples[i*5]);
 				samples[(i * 2) + 1] = samples[i * 2];
 			}
-
-
 		}
 
 		// There is one audio clock for every 4 cpu clocks, and ~15000 cycles per frame
 		public short[] audio_samples = new short[4000];
 
 		public static int[] volume_table = new int[16] {0x0000, 0x0055, 0x0079, 0x00AB, 0x00F1, 0x0155, 0x01E3, 0x02AA,
-0x03C5, 0x0555, 0x078B, 0x0AAB, 0x0F16, 0x1555, 0x1E2B, 0x2AAA};
+		0x03C5, 0x0555, 0x078B, 0x0AAB, 0x0F16, 0x1555, 0x1E2B, 0x2AAA};
 
 		public int sample_count;
 
@@ -231,14 +226,6 @@ namespace BizHawk.Emulation.Cores.Intellivision
 						E_up_down = 1;
 					}					
 				}
-				/*
-				if (reg == 0 || reg == 4)
-					clock_A = sq_per_A;
-				if (reg == 1 || reg == 5)
-					clock_A = sq_per_A;
-				if (reg == 2 || reg == 6)
-					clock_A = sq_per_A;
-					*/
 				return true;
 			}
 			return false;
@@ -299,12 +286,12 @@ namespace BizHawk.Emulation.Cores.Intellivision
 							{
 								if (env_E == 16)
 								{
-									env_E = 14;
+									env_E = 15;
 									E_up_down = -1;
 								}
 								else
 								{
-									env_E = 1;
+									env_E = 0;
 									E_up_down = 1;
 								}
 							}
diff --git a/BizHawk.Emulation.Cores/Consoles/Intellivision/STIC.cs b/BizHawk.Emulation.Cores/Consoles/Intellivision/STIC.cs
index 017b202777..9795e221ae 100644
--- a/BizHawk.Emulation.Cores/Consoles/Intellivision/STIC.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Intellivision/STIC.cs
@@ -179,58 +179,43 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			switch (addr & 0xF000)
 			{
 				case 0x0000:
-					if (addr <= 0x003F)
+					if (addr <= 0x003F && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
-						{ 
-							if (addr == 0x0021)
-							{
-								Fgbg = false;
-							}
-							return Register[addr];
-						}
-					}
-					else if (addr <= 0x007F)
-					{
-						if (in_vb_2 | !active_display)
+						if (addr == 0x0021)
 						{
-							return Register[addr - 0x0040];
+							Fgbg = false;
 						}
+						return Register[addr];
+					}
+					else if (addr>= 0x0040 && addr <= 0x007F && (in_vb_2 | !active_display))
+					{
+						return Register[addr - 0x0040];
 					}
 					break;
 				case 0x4000:
-					if (addr <= 0x403F)
+					if ((addr <= 0x403F) && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
+						if (addr == 0x4021)
 						{
-							if (addr == 0x4021)
-							{
-								Fgbg = false;
-							}
+							Fgbg = false;
 						}
 					}
 					break;
 				case 0x8000:
-					if (addr <= 0x803F)
+					if ((addr <= 0x803F) && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
+						if (addr == 0x8021)
 						{
-							if (addr == 0x8021)
-							{
-								Fgbg = false;
-							}
+							Fgbg = false;
 						}
 					}
 					break;
 				case 0xC000:
-					if (addr <= 0xC03F)
+					if ((addr <= 0xC03F) && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
+						if (addr == 0xC021)
 						{
-							if (addr == 0xC021)
-							{
-								Fgbg = false;
-							}
+							Fgbg = false;
 						}
 					}
 					break;
@@ -243,43 +228,31 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			switch (addr & 0xF000)
 			{
 				case 0x0000:
-					if (addr <= 0x003F)
+					if (addr <= 0x003F && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
-						{
-							write_reg(addr, value);
-							return true;
-						}
+						write_reg(addr, value);
+						return true;
 					}
 					break;
 				case 0x4000:
-					if (addr <= 0x403F)
+					if (addr <= 0x403F && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
-						{
-							write_reg(addr-0x4000, value);
-							return true;
-						}
+						write_reg(addr-0x4000, value);
+						return true;
 					}
 					break;
 				case 0x8000:
-					if (addr <= 0x803F)
+					if (addr <= 0x803F && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
-						{
-							write_reg(addr-0x8000, value);
-							return true;
-						}
+						write_reg(addr-0x8000, value);
+						return true;
 					}
 					break;
 				case 0xC000:
-					if (addr <= 0xC03F)
+					if (addr <= 0xC03F && (in_vb_1 | !active_display))
 					{
-						if (in_vb_1 | !active_display)
-						{
-							write_reg(addr-0xC000, value);
-							return true;
-						}
+						write_reg(addr-0xC000, value);
+						return true;
 					}
 					break;
 			}