private static long FloppyCapacity(FloppyDiskType type)
{
switch (type)
{
case FloppyDiskType.DoubleDensity:
return(Sizes.Sector * 1440);
case FloppyDiskType.HighDensity:
return(Sizes.Sector * 2880);
case FloppyDiskType.Extended:
return(Sizes.Sector * 5760);
default:
throw new ArgumentException("Invalid floppy disk type", nameof(type));
}
}
/// <summary>
/// Creates a formatted floppy disk image in a stream.
/// </summary>
/// <param name="stream">The stream to write the blank image to</param>
/// <param name="type">The type of floppy to create</param>
/// <param name="label">The volume label for the floppy (or null)</param>
/// <returns>An object that provides access to the newly created floppy disk image</returns>
public static FatFileSystem FormatFloppy(Stream stream, FloppyDiskType type, string label)
{
long pos = stream.Position;
long ticks = DateTime.UtcNow.Ticks;
uint volId = (uint)((ticks & 0xFFFF) | (ticks >> 32));
// Write the BIOS Parameter Block (BPB) - a single sector
byte[] bpb = new byte[512];
uint sectors;
if (type == FloppyDiskType.DoubleDensity)
{
sectors = 1440;
WriteBPB(bpb, sectors, FatType.Fat12, 224, 0, 1, 1, new Geometry(80, 2, 9), true, volId, label);
}
else if (type == FloppyDiskType.HighDensity)
{
sectors = 2880;
WriteBPB(bpb, sectors, FatType.Fat12, 224, 0, 1, 1, new Geometry(80, 2, 18), true, volId, label);
}
else if (type == FloppyDiskType.Extended)
{
sectors = 5760;
WriteBPB(bpb, sectors, FatType.Fat12, 224, 0, 1, 1, new Geometry(80, 2, 36), true, volId, label);
}
else
{
throw new ArgumentException("Unrecognised Floppy Disk type", "type");
}
stream.Write(bpb, 0, bpb.Length);
// Write both FAT copies
uint fatSize = CalcFatSize(sectors, FatType.Fat12, 1);
byte[] fat = new byte[fatSize * Utilities.SectorSize];
FatBuffer fatBuffer = new FatBuffer(FatType.Fat12, fat);
fatBuffer.SetNext(0, 0xFFFFFFF0);
fatBuffer.SetEndOfChain(1);
stream.Write(fat, 0, fat.Length);
stream.Write(fat, 0, fat.Length);
// Write the (empty) root directory
uint rootDirSectors = ((224 * 32) + Utilities.SectorSize - 1) / Utilities.SectorSize;
byte[] rootDir = new byte[rootDirSectors * Utilities.SectorSize];
stream.Write(rootDir, 0, rootDir.Length);
// Write a single byte at the end of the disk to ensure the stream is at least as big
// as needed for this disk image.
stream.Position = pos + (sectors * Utilities.SectorSize) - 1;
stream.WriteByte(0);
// Give the caller access to the new file system
stream.Position = pos;
return new FatFileSystem(stream);
}
private static long FloppyCapacity(FloppyDiskType type)
{
switch (type)
{
case FloppyDiskType.DoubleDensity:
return Sizes.Sector * 1440;
case FloppyDiskType.HighDensity:
return Sizes.Sector * 2880;
case FloppyDiskType.Extended:
return Sizes.Sector * 5760;
default:
throw new ArgumentException("Invalid floppy disk type", "type");
}
}
/// <summary>
/// Initializes a stream as an unformatted floppy disk.
/// </summary>
/// <param name="stream">The stream to initialize.</param>
/// <param name="ownsStream">Indicates if the new instance controls the lifetime of the stream.</param>
/// <param name="type">The type of floppy disk image to create</param>
/// <returns>An object that accesses the stream as a disk</returns>
public static DiskImageFile Initialize(Stream stream, Ownership ownsStream, FloppyDiskType type)
{
return Initialize(stream, ownsStream, FloppyCapacity(type), null);
}
/// <summary>
/// Initializes a stream as an unformatted floppy disk.
/// </summary>
/// <param name="stream">The stream to initialize.</param>
/// <param name="ownsStream">Indicates if the new instance controls the lifetime of the stream.</param>
/// <param name="type">The type of floppy disk image to create</param>
/// <returns>An object that accesses the stream as a disk</returns>
public static Disk Initialize(Stream stream, Ownership ownsStream, FloppyDiskType type)
{
return(new Disk(DiskImageFile.Initialize(stream, ownsStream, type)));
}
/// <summary>
/// Initializes a stream as an unformatted floppy disk.
/// </summary>
/// <param name="stream">The stream to initialize.</param>
/// <param name="ownsStream">Indicates if the new instance controls the lifetime of the stream.</param>
/// <param name="type">The type of floppy disk image to create.</param>
/// <returns>An object that accesses the stream as a disk.</returns>
public static Disk Initialize(Stream stream, Ownership ownsStream, FloppyDiskType type)
{
return new Disk(DiskImageFile.Initialize(stream, ownsStream, type));
}
/// <summary>
/// Initializes a stream as an unformatted floppy disk.
/// </summary>
/// <param name="stream">The stream to initialize.</param>
/// <param name="ownsStream">Indicates if the new instance controls the lifetime of the stream.</param>
/// <param name="type">The type of floppy disk image to create.</param>
/// <returns>An object that accesses the stream as a disk.</returns>
public static DiskImageFile Initialize(Stream stream, Ownership ownsStream, FloppyDiskType type)
{
return(Initialize(stream, ownsStream, FloppyCapacity(type), null));
}