diff --git a/BizHawk.Emulation/Computers/Commodore64/Experimental/Chips/Internals/Pla.cs b/BizHawk.Emulation/Computers/Commodore64/Experimental/Chips/Internals/Pla.cs
index 3247d3c225..60644dbd98 100644
--- a/BizHawk.Emulation/Computers/Commodore64/Experimental/Chips/Internals/Pla.cs
+++ b/BizHawk.Emulation/Computers/Commodore64/Experimental/Chips/Internals/Pla.cs
@@ -5,8 +5,69 @@ using System.Text;
 
 namespace BizHawk.Emulation.Computers.Commodore64.Experimental.Chips.Internals
 {
-    public class Pla
+    sealed public class Pla
     {
+        #region CACHE
+        bool a12;
+        bool a13;
+        bool a14;
+        bool a15;
+        int addr;
+        bool aec;
+        bool ba;
+        bool cachedBasic;
+        bool cachedCASRam;
+        bool cachedCharRom;
+        bool cachedGraphicsRead;
+        bool cachedIO;
+        bool cachedKernal;
+        bool cachedRomHi;
+        bool cachedRomLo;
+        bool cas;
+        bool charen;
+        bool exrom;
+        bool game;
+        bool hiram;
+        bool loram;
+        bool p0;
+        bool p1;
+        bool p2;
+        bool p3;
+        bool p4;
+        bool p5;
+        bool p6;
+        bool p7;
+        bool p9;
+        bool p10;
+        bool p11;
+        bool p12;
+        bool p13;
+        bool p14;
+        bool p15;
+        bool p16;
+        bool p17;
+        bool p18;
+        bool p19;
+        bool p20;
+        bool p21;
+        bool p22;
+        bool p23;
+        bool p24;
+        bool p25;
+        bool p26;
+        bool p27;
+        bool p28;
+        bool p30;
+        bool p31;
+        bool read;
+        int vaddr;
+        bool va12;
+        bool va13;
+        bool va14;
+        bool va15;
+        #endregion
+
+        #region INPUTS
         public Func<int> InputAddress;
         public Func<bool> InputAEC;
         public Func<bool> InputBA;
@@ -18,13 +79,15 @@ namespace BizHawk.Emulation.Computers.Commodore64.Experimental.Chips.Internals
         public Func<bool> InputLoRam;
         public Func<bool> InputRead;
         public Func<int> InputVA;
+        #endregion
 
-        virtual public bool Basic { get { return true; } }
-        virtual public bool CASRam { get { return true; } }
-        virtual public bool CharRom { get { return true; } }
-        virtual public bool GraphicsRead { get { return true; } }
-        virtual public bool IO { get { return true; } }
-        virtual public bool Kernal { get { return true; } }
+        #region OUTPUTS
+        public bool Basic { get { return cachedBasic; } }
+        public bool CASRam { get { return cachedCASRam; } }
+        public bool CharRom { get { return cachedCharRom; } }
+        public bool GraphicsRead { get { return cachedGraphicsRead; } }
+        public bool IO { get { return cachedIO; } }
+        public bool Kernal { get { return cachedKernal; } }
         public bool OutputBasic() { return Basic; }
         public bool OutputCASRam() { return CASRam; }
         public bool OutputCharRom() { return CharRom; }
@@ -33,9 +96,79 @@ namespace BizHawk.Emulation.Computers.Commodore64.Experimental.Chips.Internals
         public bool OutputKernal() { return Kernal; }
         public bool OutputRomHi() { return RomHi; }
         public bool OutputRomLo() { return RomLo; }
-        virtual public void Precache() { }
-        virtual public bool RomHi { get { return true; } }
-        virtual public bool RomLo { get { return true; } }
-        virtual public void SyncState(Serializer ser) { }
+        public bool RomHi { get { return cachedRomHi; } }
+        public bool RomLo { get { return cachedRomLo; } }
+        public void SyncState(Serializer ser) { }
+        #endregion
+
+        public void Precache() 
+        {
+            // PLA line information is from the PDF titled "The C64 PLA Dissected"
+            // Written by Thomas 'skoe' Giesel.
+
+            addr = InputAddress();
+            aec = InputAEC();
+            ba = InputBA();
+            cas = InputCAS();
+            charen = InputCharen();
+            exrom = InputExRom();
+            game = InputGame();
+            loram = InputLoRam();
+            hiram = InputHiRam();
+            read = InputRead();
+            vaddr = InputVA();
+
+            a15 = (addr & 0x08000) != 0;
+            a14 = (addr & 0x04000) != 0;
+            a13 = (addr & 0x02000) != 0;
+            a12 = (addr & 0x01000) != 0;
+            va15 = (vaddr & 0x08000) != 0;
+            va14 = (vaddr & 0x04000) != 0;
+            va13 = (vaddr & 0x02000) != 0;
+            va12 = (vaddr & 0x01000) != 0;
+
+            p0 = loram && hiram && a15 && !a14 && a13 && !aec && read && game;
+            p1 = hiram && a15 && a14 && a13 && !aec && read && game;
+            p2 = hiram && a15 && a14 && a13 && !aec && read && !exrom && !game;
+            p3 = hiram && !charen && a15 && a14 && !a13 && a12 && !aec && read && game;
+            p4 = loram && !charen && a15 && a14 && !a13 && a12 && !aec && read && game;
+            p5 = hiram && !charen && a15 && a14 && !a13 && a12 && !aec && read && !exrom && !game;
+            p6 = va14 && !va13 && va12 && aec && game;
+            p7 = va14 && !va13 && va12 && aec && !exrom && !game;
+            //p8 = cas && a15 && a14 && !a13 && a12 && !aec && !rd;
+            p9 = hiram && charen && a15 && a14 && !a13 && a12 && !aec && ba && read && game;
+            p10 = hiram && charen && a15 && a14 && !a13 && a12 && !aec && !read && game;
+            p11 = loram && charen && a15 && a14 && !a13 && a12 && !aec && ba && read && game;
+            p12 = loram && charen && a15 && a14 && !a13 && a12 && !aec && !read && game;
+            p13 = hiram && charen && a15 && a14 && !a13 && a12 && !aec && ba && read && !exrom && !game;
+            p14 = hiram && charen && a15 && a14 && !a13 && a12 && !aec && !read && !exrom && !game;
+            p15 = loram && charen && a15 && a14 && !a13 && a12 && !aec && ba && read && !exrom && !game;
+            p15 = loram && charen && a15 && a14 && !a13 && a12 && !aec && ba && read && !exrom && !game;
+            p16 = loram && charen && a15 && a14 && !a13 && a12 && !aec && !read && !exrom && !game;
+            p17 = a15 && a14 && !a13 && a12 && !aec && ba && read && exrom && !game;
+            p18 = a15 && a14 && !a13 && a12 && !aec && !read && exrom && !game;
+            p19 = loram && hiram && a15 && !a14 && !a13 && !aec && read && !exrom;
+            p20 = a15 && !a14 && !a13 && !aec && exrom && !game;
+            p21 = hiram && a15 && !a14 && a13 && !aec && read && !exrom && !game;
+            p22 = a15 && a14 && a13 && !aec && exrom && !game;
+            p23 = va13 && va12 && aec && exrom && !game;
+            p24 = !a15 && !a14 && a12 && exrom && !game;
+            p25 = !a15 && !a14 && a13 && exrom && !game;
+            p26 = !a15 && a14 && exrom && !game;
+            p27 = a15 && !a14 && a13 && exrom && !game;
+            p28 = a15 && a14 && !a13 && !a12 && exrom && !game;
+            //p29 = !cas;
+            p30 = cas;
+            p31 = !cas && a15 && a14 && !a13 && a12 && !aec && !read;
+
+            cachedCASRam = p0 || p1 || p2 || p3 || p4 || p5 || p6 || p7 || p9 || p10 || p11 || p12 || p13 || p14 || p15 || p16 || p17 || p18 || p19 || p20 || p21 || p22 || p23 || p24 || p25 || p26 || p27 || p28 || p30;
+            cachedBasic = !p0;
+            cachedKernal = !(p1 || p2);
+            cachedCharRom = !(p3 || p4 || p5 || p6 || p7);
+            cachedGraphicsRead = !p31;
+            cachedIO = !(p9 || p10 || p11 || p12 || p13 || p14 || p15 || p16 || p17 || p18);
+            cachedRomLo = !(p19 || p20);
+            cachedRomHi = !(p21 || p22 || p23);
+        }
     }
 }