diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 8b715459..1c3664b1 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -176,6 +176,8 @@
     <Compile Include="aNCHOR\ArcFPD.cs" />
     <Compile Include="aNCHOR\AudioFCD.cs" />
     <Compile Include="aNCHOR\Blowfish.cs" />
+    <Compile Include="CatSystem\ArcBinV1.cs" />
+    <Compile Include="CatSystem\ArcPidaV1.cs" />
     <Compile Include="FrontierWorks\ArcPCARC.cs" />
     <Compile Include="Artemis\ImageNekoPNG.cs" />
     <Compile Include="CsWare\AudioWAV.cs" />
diff --git a/ArcFormats/CatSystem/ArcBinV1.cs b/ArcFormats/CatSystem/ArcBinV1.cs
new file mode 100644
index 00000000..27fdb700
--- /dev/null
+++ b/ArcFormats/CatSystem/ArcBinV1.cs
@@ -0,0 +1,196 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace GameRes.Formats.CatSystem
+{
+    internal class BinEntryV1 : Entry
+    {
+        public long Size64 { get; set; }
+    }
+
+    internal class BinStreamV1 : Stream
+    {
+        private Stream mBaseStream;
+        private readonly long mOffset;
+        private readonly long mLength;
+        private long mPosition = 0L;
+        private bool mDisposed = false;
+
+        public BinStreamV1(Stream stream, long offset, long length)
+        {
+            this.mBaseStream = stream;
+            this.mOffset = offset;
+            this.mLength = length;
+        }
+
+        public override bool CanRead => !this.mDisposed;
+        public override bool CanSeek => !this.mDisposed;
+        public override bool CanWrite => false;
+        public override long Length => this.mLength;
+        public override long Position
+        {
+            get 
+            {
+                return this.mPosition;
+            }
+            set
+            {
+                if (value < 0)
+                {
+                    throw new ArgumentOutOfRangeException();
+                }
+                if (value > this.mLength)
+                {
+                    throw new ArgumentOutOfRangeException();
+                }
+                this.mPosition = value;
+            }
+        }
+
+        public override void Flush()
+        {
+        }
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            Stream stream = this.mBaseStream;
+
+            stream.Position = this.mOffset + this.mPosition;
+            int bytesRead = stream.Read(buffer, offset, (int)Math.Min(this.mLength - this.mPosition, count));
+
+            this.Decrypt(buffer, offset, bytesRead, this.mOffset, this.mPosition);
+            this.mPosition += bytesRead;
+
+            return bytesRead;
+        }
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            long pos = 0L;
+            switch (origin)
+            {
+                case SeekOrigin.Begin:
+                {
+                    pos = offset;
+                    break;
+                }
+                case SeekOrigin.Current:
+                {
+                    pos = this.mPosition + offset;
+                    break;
+                }
+                case SeekOrigin.End:
+                {
+                    pos = this.mLength + offset;
+                    break;
+                }
+            }
+
+            if (pos < 0)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+            if (pos > this.mLength)
+            {
+                throw new ArgumentOutOfRangeException();
+            }
+
+            this.mPosition = pos;
+            return pos;
+        }
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            throw new NotSupportedException();
+        }
+        protected override void Dispose(bool disposing)
+        {
+            if (!this.mDisposed)
+            {
+                if (disposing)
+                {
+                    this.mBaseStream.Dispose();
+                    this.mBaseStream = Stream.Null;
+                }
+                this.mDisposed = true;
+                base.Dispose(disposing);
+            }
+        }
+
+        protected virtual void Decrypt(byte[] buffer, long offset, int count, long fileOffset, long arcOffset)
+        {
+            for(int i = 0; i < count; ++i)
+            {
+                byte key = (byte)((fileOffset + arcOffset + i) * 0x9D + (arcOffset + i) * 0x773);
+                buffer[offset + i] -= key;
+            }
+        }
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class BinOpenerV1 : ArchiveFormat
+    {
+        public override string Tag => "BinV1/CSPACK";
+        public override string Description => "CatSystem2 resource archive";
+        public override uint Signature => 0x40674461u;
+        public override bool IsHierarchic => true;
+        public override bool CanWrite => false;
+
+        public override ArcFile TryOpen(ArcView file)
+        {
+            using (ArcViewStream stream = file.CreateStream())
+            {
+                using (BinaryReader br = new BinaryReader(stream, Encoding.Unicode, true))
+                {
+                    stream.Position = 8L;
+
+                    List<BinEntryV1> entries = new List<BinEntryV1>();
+                    {
+                        string fn = br.ReadString();
+                        while (!string.IsNullOrEmpty(fn))
+                        {
+                            BinEntryV1 e = Create<BinEntryV1>(fn);
+                            e.Offset = br.ReadUInt32();
+                            e.Size64 = 0L;
+
+                            entries.Add(e);
+
+                            fn = br.ReadString();
+                        }
+                    }
+
+                    if (entries.Any())
+                    {
+                        {
+                            BinEntryV1 last = entries.Last();
+                            last.Size64 = stream.Length - last.Offset;
+                            last.Size = (uint)last.Size64;
+                        }
+                        for (int i = 0; i < entries.Count - 1; ++i)
+                        {
+                            BinEntryV1 curr = entries[i + 0];
+                            BinEntryV1 next = entries[i + 1];
+                            curr.Size64 = next.Offset - curr.Offset;
+                            curr.Size = (uint)curr.Size64;
+                        }
+                    }
+
+                    return new ArcFile(file, this, entries.Cast<Entry>().ToList());
+                }
+            }
+        }
+        public override Stream OpenEntry(ArcFile arc, Entry entry)
+        {
+            if(!(entry is BinEntryV1 e))
+            {
+                return base.OpenEntry(arc, entry);
+            }
+            return new BinStreamV1(arc.File.CreateStream(), e.Offset, e.Size64);
+        }
+    }
+}
diff --git a/ArcFormats/CatSystem/ArcPidaV1.cs b/ArcFormats/CatSystem/ArcPidaV1.cs
new file mode 100644
index 00000000..aaca6ce6
--- /dev/null
+++ b/ArcFormats/CatSystem/ArcPidaV1.cs
@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace GameRes.Formats.CatSystem
+{
+    internal class PidaEntryV1 : Entry
+    {
+        public ushort Width;
+        public ushort Height;
+        public short OffsetX;
+        public short OffsetY;
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class PidaOpenerV1 : ArchiveFormat
+    {
+        public override string Tag => "PidaV1";
+        public override string Description => "CatSystem2 engine multi-image";
+        public override uint Signature => 0x6DF22373u;
+        public override bool IsHierarchic => true;
+        public override bool CanWrite => false;
+
+        public PidaOpenerV1()
+        {
+            ContainedFormats = new[] { "PNG" };
+        }
+
+        public override ArcFile TryOpen(ArcView file)
+        {
+            using (ArcViewStream stream = file.CreateStream())
+            {
+                using (BinaryReader br = new BinaryReader(stream, Encoding.Unicode, true))
+                {
+                    stream.Position = 8L;
+
+                    List<PidaEntryV1> entries = new List<PidaEntryV1>();
+                    {
+                        string fn = br.ReadString();
+                        while (!string.IsNullOrEmpty(fn))
+                        {
+                            PidaEntryV1 e = Create<PidaEntryV1>(fn);
+                            e.Offset = br.ReadUInt32();
+                            e.Size = 0u;
+
+                            e.Width = br.ReadUInt16();
+                            e.Height = br.ReadUInt16();
+                            e.OffsetX = br.ReadInt16();
+                            e.OffsetY = br.ReadInt16();
+
+                            e.Type = "image";
+                            entries.Add(e);
+
+                            fn = br.ReadString();
+                        }
+                    }
+
+                    if (entries.Any())
+                    {
+                        long imageDataOffset = stream.Position;
+
+                        foreach (PidaEntryV1 e in entries)
+                        {
+                            e.Offset += imageDataOffset;
+                        }
+                        {
+                            PidaEntryV1 last = entries.Last();
+                            last.Size = (uint)(stream.Length - last.Offset);
+                        }
+                        for (int i = 0; i < entries.Count - 1; ++i)
+                        {
+                            PidaEntryV1 curr = entries[i + 0];
+                            PidaEntryV1 next = entries[i + 1];
+                            curr.Size = (uint)(next.Offset - curr.Offset);
+                        }
+                    }
+
+                    return new ArcFile(file, this, entries.Cast<Entry>().ToList());
+                } 
+            }
+        }
+    }
+}