From 2caf635dd97e41d601e2c556785e45e9687d3d48 Mon Sep 17 00:00:00 2001
From: beirich <beirich@4bbf4f03-6f44-549e-7e59-35d4b0962838>
Date: Mon, 29 Aug 2011 22:49:24 +0000
Subject: [PATCH] derp :(

---
 BizHawk.Emulation/Consoles/PC Engine/ADPCM.cs | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 BizHawk.Emulation/Consoles/PC Engine/ADPCM.cs

diff --git a/BizHawk.Emulation/Consoles/PC Engine/ADPCM.cs b/BizHawk.Emulation/Consoles/PC Engine/ADPCM.cs
new file mode 100644
index 0000000000..65f966eca5
--- /dev/null
+++ b/BizHawk.Emulation/Consoles/PC Engine/ADPCM.cs	
@@ -0,0 +1,93 @@
+using System;
+
+namespace BizHawk.Emulation.Consoles.TurboGrafx
+{
+    public partial class PCEngine
+    {
+        // herein I begin to realize the downside of prodigous use of partial class.
+        // too much stuff in one namespace.
+        // partial class still rocks though. you rock, partial class.
+
+        public ushort adpcm_io_address;
+        public ushort adpcm_read_address;
+        public ushort adpcm_write_address;
+
+        public byte[] ADPCM_RAM; 
+        public byte adpcm_data_read_buffer;
+
+        public void AdpcmControlWrite(byte value)
+        {
+            Log.Error("CD","ADPCM CONTROL WRITE {0:X2}",value);
+            if ((CdIoPorts[0x0D] & 0x80) != 0 && (value & 0x80) == 0)
+            {
+                Log.Note("CD", "Reset ADPCM!");
+                adpcm_read_address = 0;
+                adpcm_write_address = 0;
+                adpcm_io_address = 0; // ???? does this happen?
+            }
+
+            else if ((value & 8) != 0)
+            {
+                adpcm_read_address = adpcm_io_address;
+                if ((value & 4) != 0)
+                    throw new Exception("nibble offset set. BLUH");
+            }
+
+            else if ((CdIoPorts[0x0D] & 2) != 0 && (value & 2) != 0)
+            {
+                adpcm_write_address = adpcm_io_address;
+                if ((value & 1) != 0)
+                    throw new Exception("nibble offset set. we should probably do something about that.");
+
+                Log.Error("CD", "Set ADPCM WRITE ADDRESS = {0:X4}", adpcm_write_address);
+            }
+        }
+
+        public void AdpcmDataWrite(byte value)
+        {
+            // TODO this should probably be buffered, but for now we do it instantly
+            //Console.WriteLine("ADPCM[{0:X4}] = {1:X2}", adpcm_write_address, value);
+            ADPCM_RAM[adpcm_write_address++] = value;
+        }
+
+        public byte AdpcmDataRead()
+        {
+            byte returnValue = adpcm_data_read_buffer;
+            adpcm_data_read_buffer = ADPCM_RAM[adpcm_read_address++];
+            return returnValue;
+        }
+
+        public bool AdpcmIsPlaying { get { return false; } }
+        public bool AdpcmBusyWriting { get { return AdpcmCdDmaRequested; } }
+        public bool AdpcmBusyReading { get { return false; } }
+
+        public void AdpcmThink()
+        {
+            if (AdpcmCdDmaRequested)
+            {
+                //Console.WriteLine("CD->ADPCM dma...");
+                if (SCSI.REQ && SCSI.IO && !SCSI.CD && !SCSI.ACK)
+                {
+                    byte dmaByte = SCSI.DataBits;
+                    if (adpcm_write_address == 0xFFF9)
+                        adpcm_write_address = 0xFFF9;
+                    //Console.WriteLine("ADPCM[{0:X4}] = {1:X2}", adpcm_write_address, dmaByte);
+                    ADPCM_RAM[adpcm_write_address++] = dmaByte;
+
+                    SCSI.ACK = false;
+                    SCSI.REQ = false;
+                    SCSI.Think();
+                }
+
+                if (SCSI.DataTransferInProgress == false)
+                {
+                    CdIoPorts[0x0B] = 0;
+                }
+            }
+        
+            // Do audio rendering and shit.
+        }
+
+        private bool AdpcmCdDmaRequested { get { return (CdIoPorts[0x0B] & 3) != 0; } }
+    }
+}