/*
* Read SECTOR_DATA CHUNK type
*/
bool _load_sector_data_chunk(chunk_header chunkhdr, AtxTrack track, BinaryReader reader)
{
int data_size = (int)chunkhdr.length - chunk_header_bytecount;
if (track.sector_count > 0 && track.sectors.Any() == false)
{
Console.WriteLine($"\tWARNING:: SECTOR_DATA chunk presented before SECTOR_LIST chunk");
}
else
{
int actual_sectors = 0;
string missing_sectors = "";
foreach (var s in track.sectors)
{
if ((s.status & (byte)SectorStatus.MISSING_DATA) == 0)
{
actual_sectors++;
}
else
{
missing_sectors = "; missing sectors accounted for";
}
}
int calculated_bytes = actual_sectors * _sector_size;
if (data_size != calculated_bytes)
{
Console.WriteLine($"\tWARNING:: Chunk data size as given in header ({data_size:N0}) != expected size ({actual_sectors} * {_sector_size} = {calculated_bytes:N0}){missing_sectors}");
}
}
Console.WriteLine($"\tReading {data_size:N0} bytes of track sector data");
try
{
track.data = reader.ReadBytes(data_size);
}
catch
{
Console.WriteLine($"\tERROR:: Failed to read sector data");
return(false);
}
/*
* The start_data value in each sector header is an offset into the overall Track Record,
* including headers and other chunks that preceed it, where that sector's actual data begins
* in the data chunk.
*
* We record the number of bytes into the Track Record the data chunk begins so we
* can adjust the start_data value later when we want to read the right section from this
* array of bytes.
*/
track.offset_to_data_start = track.record_bytes_read;
// Keep a count of how many bytes we've read into the Track Record
track.record_bytes_read += data_size;
_sector_data_bytes += data_size;
return(true);
}
/*
* Read EXTENDED_DATA CHUNK type
*/
bool _load_extended_sector_chunk(chunk_header chunkhdr, AtxTrack track, BinaryReader reader)
{
if (chunkhdr.length != chunk_header_bytecount)
{
Console.WriteLine($"\tERROR:: Chunk length {chunkhdr.length} != expected ({chunk_header_bytecount})");
}
if (chunkhdr.sector_index >= track.sector_count)
{
Console.WriteLine("\tERROR:: Extended sector index > track sector count");
return(false);
}
UInt16 xsize;
switch ((ExtendedSize)chunkhdr.header_data)
{
case ExtendedSize.EXTENDEDSIZE_128:
xsize = 128;
break;
case ExtendedSize.EXTENDEDSIZE_256:
xsize = 256;
break;
case ExtendedSize.EXTENDEDSIZE_512:
xsize = 512;
break;
case ExtendedSize.EXTENDEDSIZE_1024:
xsize = 1024;
break;
default:
Console.WriteLine($"\tERROR:: Invalid extended sector value {chunkhdr.header_data}");
return(false);
}
track.sectors[chunkhdr.sector_index].extendedsize = xsize;
int sector_number = track.sectors[chunkhdr.sector_index].number;
int overall_sector_number = track.track_number * _sectors_per_track + sector_number;
Console.WriteLine($"\tExtended sector: index={chunkhdr.sector_index}, num={sector_number} ({overall_sector_number}, ${overall_sector_number:x3}), size={xsize}");
return(true);
}
/*
* Read WEAK_SECTOR CHUNK type
*/
bool _load_weak_sector_chunk(chunk_header chunkhdr, AtxTrack track, BinaryReader reader)
{
if (chunkhdr.length != chunk_header_bytecount)
{
Console.WriteLine($"\tERROR:: Chunk length {chunkhdr.length} != expected ({chunk_header_bytecount})");
}
if (chunkhdr.sector_index >= track.sector_count)
{
Console.WriteLine("\tERROR:: Weak sector index > track sector count");
return(false);
}
track.sectors[chunkhdr.sector_index].weakoffset = chunkhdr.header_data;
int sector_number = track.sectors[chunkhdr.sector_index].number;
int overall_sector_number = track.track_number * _sectors_per_track + sector_number;
Console.WriteLine($"\tWeak sector: index={chunkhdr.sector_index}, num={sector_number} ({overall_sector_number}, ${overall_sector_number:x3}), offset={chunkhdr.header_data}");
return(true);
}
/*
* Read UNKNOWN CHUNK type
*/
bool _load_unknown_chunk(chunk_header chunkhdr, BinaryReader reader)
{
Console.WriteLine($"WARNING:: Unknown chunk type");
return(true);
}
/*
* Read SECTOR_LIST CHUNK type
*/
bool _load_sector_list_chunk(chunk_header chunkhdr, AtxTrack track, BinaryReader reader)
{
int expected = chunk_header_bytecount + track.sector_count * sector_header_bytecount;
if (chunkhdr.length != expected)
{
Console.WriteLine($"\tWARNING:: Chunk length {chunkhdr.length} != expected ({expected})");
}
// Try to read sector data for sector_count sectors
for (int i = 0; i < track.sector_count; i++)
{
AtxSector sect = new AtxSector();
try
{
sect.number = reader.ReadByte();
sect.status = reader.ReadByte();
sect.position = reader.ReadUInt16();
sect.start_data = reader.ReadUInt32();
track.record_bytes_read += sector_header_bytecount;
}
catch
{
Console.WriteLine($"\tERROR:: Failed to read sector list header for sector at index {i}");
return(false);
}
int overall_sector_number = track.track_number * _sectors_per_track + sect.number;
string overall = $"({overall_sector_number}, ${overall_sector_number:x3})";
if (sect.status != 0)
{
Console.Write($"\tSector index={i}, num={sect.number} {overall}, flags=");
if ((sect.status & (byte)SectorStatus.DELETED) != 0)
{
Console.Write("DELETED ");
}
if ((sect.status & (byte)SectorStatus.MISSING_DATA) != 0)
{
Console.Write("MISSING_DATA ");
}
if ((sect.status & (byte)SectorStatus.EXTENDED) != 0)
{
Console.Write("EXTENDED ");
}
if ((sect.status & (byte)SectorStatus.FDC_CRC_ERROR) != 0)
{
Console.Write("CRC_ERROR ");
}
if ((sect.status & (byte)SectorStatus.FDC_LOSTDATA_ERROR) != 0)
{
Console.Write("LOSTDATA_ERROR");
}
if ((sect.status & (byte)SectorStatus.FDC_DATAREQ_PENDING) != 0)
{
Console.Write("DATAREQ_PENDING");
}
Console.WriteLine();
if ((sect.status & ~(byte)(SectorStatus.DELETED | SectorStatus.MISSING_DATA |
SectorStatus.EXTENDED | SectorStatus.FDC_CRC_ERROR |
SectorStatus.FDC_DATAREQ_PENDING | SectorStatus.FDC_LOSTDATA_ERROR)) != 0)
{
Console.WriteLine($"\tWARNING:: Unknown sector status flag 0x{sect.status:X2}");
}
}
if (sect.number > _sectors_per_track)
{
Console.WriteLine($"\tWARNING:: Sector index={i}, number={sect.number} > {_sectors_per_track}");
}
if (sect.number == 0)
{
Console.WriteLine($"\tWARNING:: Sector index={i} has sector #0");
}
if (sect.position >= ANGULAR_UNIT_COUNT)
{
Console.WriteLine($"\tWARNING:: Sector index={i}, num={sect.number} {overall}, angular position {sect.position} > {ANGULAR_UNIT_COUNT - 1}");
}
// See if this is a duplicate
foreach (var s in track.sectors)
{
if (s.number == sect.number)
{
Console.WriteLine($"\tDUPLICATE sector #{sect.number:D2} {overall}");
break;
}
}
// Add to the list
track.sectors.Add(sect);
}
Console.WriteLine($"\tRead {track.sectors.Count} sector headers for track {track.track_number}");
// Report on any missing sectors
for (int i = 1; i <= _sectors_per_track; i++)
{
if (track.sectors.Find(x => x.number == i) == null)
{
Console.WriteLine($"\tMISSING sector #{i}");
}
}
return(true);
}
