add the crudest possible psx disc detector. now other people can watch somewhat garbled psx game intros

BizHawk.Emulation/Consoles/PSX/Octoshock.cs

@@ -22,6 +22,21 @@ namespace BizHawk.Emulation.Consoles.PSX
 		public bool StartAsyncSound() { return true; }
 		public void EndAsyncSound() { }
 
+		public static bool CheckIsPSX(DiscSystem.Disc disc)
+		{
+			bool ret = false;
+
+			byte[] buf = new byte[59];
+			disc.ReadLBA_2352_Flat(0x24D8, buf, 0, 59);
+			string sig = System.Text.ASCIIEncoding.ASCII.GetString(buf);
+
+			//this string is considered highly unlikely to exist anywhere besides a psx disc
+			if (sig == "          Licensed  by          Sony Computer Entertainment")
+				ret = true;
+
+			return ret;
+		}
+
 		//we can only have one active core at a time, due to the lib being so static.
 		//so we'll track the current one here and detach the previous one whenever a new one is booted up.
 		static Octoshock CurrOctoshockCore;

BizHawk.Emulation/DiscSystem/Disc.API.cs

@@ -92,6 +92,30 @@ namespace BizHawk.DiscSystem
 			Array.Copy(temp, 16, buffer, offset, 2048);
 		}
 
+		/// <summary>
+		/// reads logical data from a flat disc address space
+		/// useful for plucking data from a known location on the disc
+		/// </summary>
+		public void ReadLBA_2352_Flat(long disc_offset, byte[] buffer, int offset, int length)
+		{
+			int secsize = 2352;
+			byte[] lba_buf = new byte[secsize];
+			while(length > 0)
+			{
+				int lba = (int)(disc_offset / secsize);
+				int lba_within = (int)(disc_offset % secsize);
+				int todo = length;
+				int remains_in_lba = secsize - lba_within;
+				if (remains_in_lba < todo)
+					todo = remains_in_lba;
+				ReadLBA_2352(lba, lba_buf, 0);
+				Array.Copy(lba_buf, lba_within, buffer, offset, todo);
+				offset += todo;
+				length -= todo;
+				lba_within = 0;
+			}
+		}
+
 
 		/// <summary>
 		/// Returns a SectorEntry from which you can retrieve various interesting pieces of information about the sector.

BizHawk.MultiClient/MainForm.cs

@@ -1435,12 +1435,13 @@ namespace BizHawk.MultiClient
 							// In the future we need to do something smarter, possibly including simply asking the user
 							// what system the game is for.
 
-							if (System.Windows.Forms.SystemInformation.ComputerName == "ZERO-XP")
+							if (BizHawk.Emulation.Consoles.PSX.Octoshock.CheckIsPSX(disc))
 							{
 								game = new GameInfo();
 								game.System = "PSX";
 								game.Name = Path.GetFileNameWithoutExtension(file.Name);
 								game.Hash = hash;
+								disc.Dispose();
 							}
 							else
 							{