/// <summary>
/// Commits modified sector data back to the emulated disk.
/// Intended to be called at the end of the sector / beginning of the next.
/// </summary>
private void CommitSector()
{
if (_pack == null)
{
return;
}
DiabloDiskSector sector = _pack.GetSector(_cylinder, _head, _sector);
// Header (2 words data, 1 word cksum)
for (int i = HeaderOffset + 1, j = 1; i < HeaderOffset + 3; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
sector.Header[j] = _sectorData[i].Data;
}
// Label (8 words data, 1 word cksum)
for (int i = LabelOffset + 1, j = 7; i < LabelOffset + 9; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
sector.Label[j] = _sectorData[i].Data;
}
// sector data (256 words data, 1 word cksum)
for (int i = DataOffset + 1, j = 255; i < DataOffset + 257; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
sector.Data[j] = _sectorData[i].Data;
}
}
public void Save(Stream imageStream)
{
for (int cylinder = 0; cylinder < _geometry.Cylinders; cylinder++)
{
for (int track = 0; track < _geometry.Tracks; track++)
{
for (int sector = 0; sector < _geometry.Sectors; sector++)
{
byte[] header = new byte[4]; // 2 words
byte[] label = new byte[16]; // 8 words
byte[] data = new byte[512]; // 256 words
//
// Bitsavers images have an extra word in the header for some reason.
// We will follow this 'standard' when writing out.
// TODO: should support different formats ("correct" raw, Alto CopyDisk format, etc.)
//
byte[] dummy = new byte[2];
imageStream.Write(dummy, 0, 2);
DiabloDiskSector s = _sectors[cylinder, track, sector];
WriteWordBuffer(imageStream, s.Header);
WriteWordBuffer(imageStream, s.Label);
WriteWordBuffer(imageStream, s.Data);
}
}
}
}
public DiabloPack(DiabloDiskType type)
{
_diskType = type;
_packName = null;
_geometry = new DiskGeometry(type == DiabloDiskType.Diablo31 ? 203 : 406, 2, 12);
_sectors = new DiabloDiskSector[_geometry.Cylinders, _geometry.Tracks, _geometry.Sectors];
}
public void Load(Stream imageStream, string path, bool reverseByteOrder)
{
_packName = path;
for (int cylinder = 0; cylinder < _geometry.Cylinders; cylinder++)
{
for (int track = 0; track < _geometry.Tracks; track++)
{
for (int sector = 0; sector < _geometry.Sectors; sector++)
{
byte[] header = new byte[4]; // 2 words
byte[] label = new byte[16]; // 8 words
byte[] data = new byte[512]; // 256 words
//
// Bitsavers images have an extra word in the header for some reason.
// ignore it.
// TODO: should support different formats ("correct" raw, Alto CopyDisk format, etc.)
//
imageStream.Seek(2, SeekOrigin.Current);
if (imageStream.Read(header, 0, header.Length) != header.Length)
{
throw new InvalidOperationException("Short read while reading sector header.");
}
if (imageStream.Read(label, 0, label.Length) != label.Length)
{
throw new InvalidOperationException("Short read while reading sector label.");
}
if (imageStream.Read(data, 0, data.Length) != data.Length)
{
throw new InvalidOperationException("Short read while reading sector data.");
}
if (reverseByteOrder)
{
SwapBytes(header);
SwapBytes(label);
SwapBytes(data);
}
_sectors[cylinder, track, sector] = new DiabloDiskSector(header, label, data);
}
}
}
if (imageStream.Position != imageStream.Length)
{
throw new InvalidOperationException("Extra data at end of image file.");
}
}
private void LoadSector()
{
if (_pack == null)
{
return;
}
//
// Pull data off disk and pack it into our faked-up sector.
// Note that this data is packed in in REVERSE ORDER because that's
// how it gets written out and it's how the Alto expects it to be read back in.
//
DiabloDiskSector sector = _pack.GetSector(_cylinder, _head, _sector);
// Header (2 words data, 1 word cksum)
for (int i = HeaderOffset + 1, j = 1; i < HeaderOffset + 3; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
_sectorData[i] = new DataCell(sector.Header[j], CellType.Data);
}
ushort checksum = CalculateChecksum(_sectorData, HeaderOffset + 1, 2);
_sectorData[HeaderOffset + 3].Data = checksum;
Log.Write(LogType.Verbose, LogComponent.DiskController, "Header checksum for C/H/S {0}/{1}/{2} is {3}", _cylinder, _head, _sector, Conversion.ToOctal(checksum));
// Label (8 words data, 1 word cksum)
for (int i = LabelOffset + 1, j = 7; i < LabelOffset + 9; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
_sectorData[i] = new DataCell(sector.Label[j], CellType.Data);
}
checksum = CalculateChecksum(_sectorData, LabelOffset + 1, 8);
_sectorData[LabelOffset + 9].Data = checksum;
Log.Write(LogType.Verbose, LogComponent.DiskController, "Label checksum for C/H/S {0}/{1}/{2} is {3}", _cylinder, _head, _sector, Conversion.ToOctal(checksum));
// sector data (256 words data, 1 word cksum)
for (int i = DataOffset + 1, j = 255; i < DataOffset + 257; i++, j--)
{
// actual data to be loaded from disk / cksum calculated
_sectorData[i] = new DataCell(sector.Data[j], CellType.Data);
}
checksum = CalculateChecksum(_sectorData, DataOffset + 1, 256);
_sectorData[DataOffset + 257].Data = checksum;
Log.Write(LogType.Verbose, LogComponent.DiskController, "Data checksum for C/H/S {0}/{1}/{2} is {3}", _cylinder, _head, _sector, Conversion.ToOctal(checksum));
}