/// <summary> /// Read a whole track and cache it /// </summary> /// <param name="stream">The stream to read from</param> /// <param name="cyl">The cylinder number of the track being read.</param> /// <param name="head">The head number of the track being read.</param> void ReadTrack(Stream stream, int cyl, int head) { byte[] sectorData; byte[] crc; short calculatedCRC; for (int sect = 1; sect < imageInfo.SectorsPerTrack + 1; sect++) { /* read the sector header */ byte[] sheaderBuffer = new byte[6]; stream.Read(sheaderBuffer, 0, 6); IntPtr sectPtr = Marshal.AllocHGlobal(6); Marshal.Copy(sheaderBuffer, 0, sectPtr, 6); WCDiskImageSectorHeader sheader = (WCDiskImageSectorHeader)Marshal.PtrToStructure(sectPtr, typeof(WCDiskImageSectorHeader)); Marshal.FreeHGlobal(sectPtr); /* validate the sector header */ if ((sheader.cylinder != cyl) || (sheader.head != head) || (sheader.sector != sect)) { throw new InvalidDataException(String.Format("Unexpected sector encountered. Found CHS {0},{1},{2} but expected {3},{4},{5}", sheader.cylinder, sheader.head, sheader.sector, cyl, head, sect)); } sectorData = new byte[512]; /* read the sector data */ switch (sheader.flag) { case SectorFlag.Normal: /* read a normal sector and store it in cache */ stream.Read(sectorData, 0, 512); sectorCache[(cyl, head, sect)] = sectorData;
public bool Open(IFilter imageFilter) { string comments = string.Empty; Stream stream = imageFilter.GetDataForkStream(); stream.Seek(0, SeekOrigin.Begin); byte[] header = new byte[32]; stream.Read(header, 0, 32); WCDiskImageFileHeader fheader = Marshal.ByteArrayToStructureLittleEndian <WCDiskImageFileHeader>(header); DicConsole.DebugWriteLine("d2f plugin", "Detected WC DISK IMAGE with {0} heads, {1} tracks and {2} sectors per track.", fheader.heads, fheader.cylinders, fheader.sectorsPerTrack); imageInfo.Cylinders = fheader.cylinders; imageInfo.SectorsPerTrack = fheader.sectorsPerTrack; imageInfo.SectorSize = 512; // only 512 bytes per sector supported imageInfo.Heads = fheader.heads; imageInfo.Sectors = imageInfo.Heads * imageInfo.Cylinders * imageInfo.SectorsPerTrack; imageInfo.ImageSize = imageInfo.Sectors * imageInfo.SectorSize; imageInfo.XmlMediaType = XmlMediaType.BlockMedia; imageInfo.CreationTime = imageFilter.GetCreationTime(); imageInfo.LastModificationTime = imageFilter.GetLastWriteTime(); imageInfo.MediaTitle = Path.GetFileNameWithoutExtension(imageFilter.GetFilename()); imageInfo.MediaType = Geometry.GetMediaType(((ushort)imageInfo.Cylinders, (byte)imageInfo.Heads, (ushort)imageInfo.SectorsPerTrack, 512, MediaEncoding.MFM, false)); /* buffer the entire disk in memory */ for (int cyl = 0; cyl < imageInfo.Cylinders; cyl++) { for (int head = 0; head < imageInfo.Heads; head++) { ReadTrack(stream, cyl, head); } } /* if there are extra tracks, read them as well */ if (fheader.extraTracks[0] == 1) { DicConsole.DebugWriteLine("d2f plugin", "Extra track 1 (head 0) present, reading"); ReadTrack(stream, (int)imageInfo.Cylinders, 0); } if (fheader.extraTracks[1] == 1) { DicConsole.DebugWriteLine("d2f plugin", "Extra track 1 (head 1) present, reading"); ReadTrack(stream, (int)imageInfo.Cylinders, 1); } if (fheader.extraTracks[2] == 1) { DicConsole.DebugWriteLine("d2f plugin", "Extra track 2 (head 0) present, reading"); ReadTrack(stream, (int)imageInfo.Cylinders + 1, 0); } if (fheader.extraTracks[3] == 1) { DicConsole.DebugWriteLine("d2f plugin", "Extra track 2 (head 1) present, reading"); ReadTrack(stream, (int)imageInfo.Cylinders + 1, 1); } /* adjust number of cylinders */ if (fheader.extraTracks[0] == 1 || fheader.extraTracks[1] == 1) { imageInfo.Cylinders++; } if (fheader.extraTracks[2] == 1 || fheader.extraTracks[3] == 1) { imageInfo.Cylinders++; } /* read the comment and directory data if present */ if (fheader.extraFlags.HasFlag(ExtraFlag.Comment)) { DicConsole.DebugWriteLine("d2f plugin", "Comment present, reading"); byte[] sheaderBuffer = new byte[6]; stream.Read(sheaderBuffer, 0, 6); WCDiskImageSectorHeader sheader = Marshal.ByteArrayToStructureLittleEndian <WCDiskImageSectorHeader>(sheaderBuffer); if (sheader.flag != SectorFlag.Comment) { throw new InvalidDataException(string.Format("Invalid sector type '{0}' encountered", sheader.flag.ToString())); } byte[] comm = new byte[sheader.crc]; stream.Read(comm, 0, sheader.crc); comments += Encoding.ASCII.GetString(comm) + Environment.NewLine; } if (fheader.extraFlags.HasFlag(ExtraFlag.Directory)) { DicConsole.DebugWriteLine("d2f plugin", "Directory listing present, reading"); byte[] sheaderBuffer = new byte[6]; stream.Read(sheaderBuffer, 0, 6); WCDiskImageSectorHeader sheader = Marshal.ByteArrayToStructureLittleEndian <WCDiskImageSectorHeader>(sheaderBuffer); if (sheader.flag != SectorFlag.Directory) { throw new InvalidDataException(string.Format("Invalid sector type '{0}' encountered", sheader.flag.ToString())); } byte[] dir = new byte[sheader.crc]; stream.Read(dir, 0, sheader.crc); comments += Encoding.ASCII.GetString(dir); } if (comments.Length > 0) { imageInfo.Comments = comments; } // save some variables for later use fileHeader = fheader; wcImageFilter = imageFilter; return(true); }