public static byte[] MarshalSector(RawSector sector)
{
if (sector == null)
{
return(null);
}
MemoryStream raw = new MemoryStream();
raw.Write(sector.addressField.prologue, 0, sector.addressField.prologue.Length);
raw.WriteByte(sector.addressField.track);
raw.WriteByte(sector.addressField.sector);
raw.WriteByte(sector.addressField.side);
raw.WriteByte((byte)sector.addressField.format);
raw.WriteByte(sector.addressField.checksum);
raw.Write(sector.innerGap, 0, sector.innerGap.Length);
raw.Write(sector.dataField.prologue, 0, sector.dataField.prologue.Length);
raw.WriteByte(sector.dataField.spare);
raw.Write(sector.dataField.data, 0, sector.dataField.data.Length);
raw.Write(sector.dataField.checksum, 0, sector.dataField.checksum.Length);
raw.Write(sector.dataField.epilogue, 0, sector.dataField.epilogue.Length);
raw.Write(sector.gap, 0, sector.gap.Length);
return(raw.ToArray());
}
public static byte[] DecodeSector(RawSector sector)
{
if (sector.addressField.prologue[0] != 0xD5 || sector.addressField.prologue[1] != 0xAA)
{
return(null);
}
// Pre DOS 3.3
if (sector.addressField.prologue[2] == 0xB5)
{
return(Decode5and3(sector.dataField.data));
}
// DOS 3.3
return(sector.addressField.prologue[2] == 0x96 ? Decode6and2(sector.dataField.data) : null);
// Unknown
// Not Apple ][ GCR?
}
public static byte[] MarshalSector(RawSector sector)
{
if (sector == null)
{
return(null);
}
var raw = new MemoryStream();
raw.Write(sector.addressField.prologue, 0, sector.addressField.prologue.Length);
raw.Write(sector.addressField.volume, 0, sector.addressField.volume.Length);
raw.Write(sector.addressField.track, 0, sector.addressField.track.Length);
raw.Write(sector.addressField.sector, 0, sector.addressField.sector.Length);
raw.Write(sector.addressField.checksum, 0, sector.addressField.checksum.Length);
raw.Write(sector.addressField.epilogue, 0, sector.addressField.epilogue.Length);
raw.Write(sector.innerGap, 0, sector.innerGap.Length);
raw.Write(sector.dataField.prologue, 0, sector.dataField.prologue.Length);
raw.Write(sector.dataField.data, 0, sector.dataField.data.Length);
raw.WriteByte(sector.dataField.checksum);
raw.Write(sector.dataField.epilogue, 0, sector.dataField.epilogue.Length);
raw.Write(sector.gap, 0, sector.gap.Length);
return(raw.ToArray());
}
public static bool IsAppleSonyGCR(byte[] data)
{
RawSector sector = MarshalSector(data, out int position);
return(sector != null && position != 0);
}
public static RawTrack MarshalTrack(byte[] data, out int endOffset, int offset = 0)
{
int position = offset;
bool firstSector = true;
bool onSync = false;
MemoryStream gaps = new MemoryStream();
int count = 0;
List <RawSector> sectors = new List <RawSector>();
byte trackNumber = 0;
byte sideNumber = 0;
endOffset = offset;
while (position < data.Length && data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
count++;
position++;
onSync = count >= 5;
}
if (position >= data.Length)
{
return(null);
}
if (!onSync)
{
return(null);
}
while (position < data.Length)
{
int oldPosition = position;
RawSector sector = MarshalSector(data, out position, position);
if (sector == null)
{
break;
}
if (firstSector)
{
trackNumber = sector.addressField.track;
sideNumber = sector.addressField.side;
firstSector = false;
}
if (sector.addressField.track != trackNumber || sector.addressField.side != sideNumber)
{
position = oldPosition;
break;
}
sectors.Add(sector);
}
if (sectors.Count == 0)
{
return(null);
}
RawTrack track = new RawTrack {
gap = gaps.ToArray(), sectors = sectors.ToArray()
};
endOffset = position;
return(track);
}
public static RawSector MarshalSector(byte[] data, out int endOffset, int offset = 0)
{
endOffset = offset;
// Not an Apple ][ GCR sector
if (data == null || data.Length < 363)
{
return(null);
}
int position = offset;
try
{
while (position < data.Length)
{
// Prologue found
if (data[position] == 0xD5 && data[position + 1] == 0xAA && data[position + 2] == 0x96)
{
// Epilogue not in correct position
if (data[position + 8] != 0xDE || data[position + 9] != 0xAA)
{
return(null);
}
RawSector sector = new RawSector
{
addressField = new RawAddressField
{
prologue = new[] { data[position], data[position + 1], data[position + 2] },
track = data[position + 3],
sector = data[position + 4],
side = data[position + 5],
format = (AppleEncodedFormat)data[position + 6],
checksum = data[position + 7],
epilogue = new[] { data[position + 8], data[position + 9] }
}
};
position += 10;
int syncCount = 0;
bool onSync = false;
MemoryStream gaps = new MemoryStream();
while (data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
syncCount++;
onSync = syncCount >= 5;
position++;
}
// Lost sync
if (!onSync)
{
return(null);
}
// Prologue not found
if (data[position] != 0xDE || data[position + 1] != 0xAA || data[position + 2] != 0xAD)
{
return(null);
}
sector.innerGap = gaps.ToArray();
sector.dataField = new RawDataField
{
prologue = new[] { data[position], data[position + 1], data[position + 2] },
spare = data[position + 3]
};
position += 4;
gaps = new MemoryStream();
// Read data until epilogue is found
while (data[position + 4] != 0xD5 || data[position + 5] != 0xAA)
{
gaps.WriteByte(data[position]);
position++;
// No space left for epilogue
if (position + 7 > data.Length)
{
return(null);
}
}
sector.dataField.data = gaps.ToArray();
sector.dataField.checksum = new byte[4];
sector.dataField.checksum[0] = data[position];
sector.dataField.checksum[1] = data[position + 2];
sector.dataField.checksum[2] = data[position + 3];
sector.dataField.checksum[3] = data[position + 4];
sector.dataField.epilogue = new byte[2];
sector.dataField.epilogue[0] = data[position + 5];
sector.dataField.epilogue[1] = data[position + 6];
position += 7;
gaps = new MemoryStream();
// Read gap, if any
while (position < data.Length && data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
position++;
}
// Reduces last sector gap so doesn't eat next tracks's gap
if (gaps.Length > 5)
{
gaps.SetLength(gaps.Length / 2);
position -= (int)gaps.Length;
}
sector.gap = gaps.ToArray();
// Return current position to be able to read separate sectors
endOffset = position;
return(sector);
}
if (data[position] == 0xFF)
{
position++;
}
// Found data that is not sync or a prologue
else
{
return(null);
}
}
}
catch (IndexOutOfRangeException) { return(null); }
return(null);
}
public static byte[] DecodeSector(RawSector sector)
{
if (sector.addressField.prologue[0] != 0xD5 || sector.addressField.prologue[1] != 0xAA ||
sector.addressField.prologue[2] != 0x96)
{
return(null);
}
byte[] bf1 = new byte[175];
byte[] bf2 = new byte[175];
byte[] bf3 = new byte[175];
byte[] nib_data = sector.dataField.data;
MemoryStream ms = new MemoryStream();
int j = 0;
byte w3 = 0;
for (int i = 0; i <= 174; i++)
{
byte w4 = nib_data[j++];
byte w1 = nib_data[j++];
byte w2 = nib_data[j++];
if (i != 174)
{
w3 = nib_data[j++];
}
bf1[i] = (byte)(((w1 & 0x3F) | ((w4 << 2) & 0xC0)) & 0x0F);
bf2[i] = (byte)(((w2 & 0x3F) | ((w4 << 4) & 0xC0)) & 0x0F);
bf3[i] = (byte)(((w3 & 0x3F) | ((w4 << 6) & 0xC0)) & 0x0F);
}
j = 0;
uint ck1 = 0;
uint ck2 = 0;
uint ck3 = 0;
while (true)
{
ck1 = (ck1 & 0xFF) << 1;
if ((ck1 & 0x0100) > 0)
{
ck1++;
}
byte carry = (byte)((bf1[j] ^ ck1) & 0xFF);
ck3 += carry;
if ((ck1 & 0x0100) > 0)
{
ck3++;
ck1 &= 0xFF;
}
ms.WriteByte(carry);
carry = (byte)((bf2[j] ^ ck3) & 0xFF);
ck2 += carry;
if (ck3 > 0xFF)
{
ck2++;
ck3 &= 0xFF;
}
ms.WriteByte(carry);
if (ms.Length == 524)
{
break;
}
carry = (byte)((bf3[j] ^ ck2) & 0xFF);
ck1 += carry;
if (ck2 > 0xFF)
{
ck1++;
ck2 &= 0xFF;
}
ms.WriteByte(carry);
j++;
}
return(ms.ToArray());
// Not Apple Sony GCR?
}
public static RawTrack MarshalTrack(byte[] data, out int endOffset, int offset = 0)
{
int position = offset;
bool firstSector = true;
bool onSync = false;
MemoryStream gaps = new MemoryStream();
int count = 0;
List <RawSector> sectors = new List <RawSector>();
byte[] trackNumber = new byte[2];
endOffset = offset;
while (position < data.Length && data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
count++;
position++;
onSync = count >= 5;
}
if (position >= data.Length)
{
return(null);
}
if (!onSync)
{
return(null);
}
while (position < data.Length)
{
int oldPosition = position;
RawSector sector = MarshalSector(data, out position, position);
if (sector == null)
{
break;
}
if (firstSector)
{
trackNumber[0] = sector.addressField.track[0];
trackNumber[1] = sector.addressField.track[1];
firstSector = false;
}
if (sector.addressField.track[0] != trackNumber[0] || sector.addressField.track[1] != trackNumber[1])
{
position = oldPosition;
break;
}
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Adding sector {0} of track {1}",
(((sector.addressField.sector[0] & 0x55) << 1) |
(sector.addressField.sector[1] & 0x55)) & 0xFF,
(((sector.addressField.track[0] & 0x55) << 1) |
(sector.addressField.track[1] & 0x55)) & 0xFF);
sectors.Add(sector);
}
if (sectors.Count == 0)
{
return(null);
}
RawTrack track = new RawTrack {
gap = gaps.ToArray(), sectors = sectors.ToArray()
};
endOffset = position;
return(track);
}
public static RawSector MarshalSector(byte[] data, out int endOffset, int offset = 0)
{
endOffset = offset;
// Not an Apple ][ GCR sector
if (data == null || data.Length < 363)
{
return(null);
}
int position = offset;
try
{
while (position < data.Length)
{
// Prologue found
if (data[position] == 0xD5 && data[position + 1] == 0xAA)
{
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Prologue found at {0}", position);
// Epilogue not in correct position
if (data[position + 11] != 0xDE || data[position + 12] != 0xAA)
{
return(null);
}
RawSector sector = new RawSector
{
addressField = new RawAddressField
{
prologue = new[] { data[position], data[position + 1], data[position + 2] },
volume = new[] { data[position + 3], data[position + 4] },
track = new[] { data[position + 5], data[position + 6] },
sector = new[] { data[position + 7], data[position + 8] },
checksum = new[] { data[position + 9], data[position + 10] },
epilogue = new[]
{ data[position + 11], data[position + 12], data[position + 13] }
}
};
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Volume {0}",
(((sector.addressField.volume[0] & 0x55) << 1) |
(sector.addressField.volume[1] & 0x55)) & 0xFF);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Track {0}",
(((sector.addressField.track[0] & 0x55) << 1) |
(sector.addressField.track[1] & 0x55)) & 0xFF);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Sector {0}",
(((sector.addressField.sector[0] & 0x55) << 1) |
(sector.addressField.sector[1] & 0x55)) & 0xFF);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Checksum {0}",
(((sector.addressField.checksum[0] & 0x55) << 1) |
(sector.addressField.checksum[1] & 0x55)) & 0xFF);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Epilogue {0:X2}{1:X2}{2:X2}",
sector.addressField.epilogue[0], sector.addressField.epilogue[1],
sector.addressField.epilogue[2]);
position += 14;
int syncCount = 0;
bool onSync = false;
MemoryStream gaps = new MemoryStream();
while (data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
syncCount++;
onSync = syncCount >= 5;
position++;
}
// Lost sync
if (!onSync)
{
return(null);
}
// Prologue not found
if (data[position] != 0xD5 || data[position + 1] != 0xAA)
{
return(null);
}
sector.innerGap = gaps.ToArray();
sector.dataField = new RawDataField();
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Inner gap has {0} bytes",
sector.innerGap.Length);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Prologue found at {0}", position);
sector.dataField.prologue = new byte[3];
sector.dataField.prologue[0] = data[position];
sector.dataField.prologue[1] = data[position + 1];
sector.dataField.prologue[2] = data[position + 2];
position += 3;
gaps = new MemoryStream();
// Read data until epilogue is found
while (data[position + 1] != 0xDE || data[position + 2] != 0xAA)
{
gaps.WriteByte(data[position]);
position++;
// No space left for epilogue
if (position + 4 > data.Length)
{
return(null);
}
}
sector.dataField.data = gaps.ToArray();
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Data has {0} bytes",
sector.dataField.data.Length);
sector.dataField.checksum = data[position];
sector.dataField.epilogue = new byte[3];
sector.dataField.epilogue[0] = data[position + 1];
sector.dataField.epilogue[1] = data[position + 2];
sector.dataField.epilogue[2] = data[position + 3];
position += 4;
gaps = new MemoryStream();
// Read gap, if any
while (position < data.Length && data[position] == 0xFF)
{
gaps.WriteByte(data[position]);
position++;
}
// Reduces last sector gap so doesn't eat next tracks's gap
if (gaps.Length > 5)
{
gaps.SetLength(gaps.Length / 2);
position -= (int)gaps.Length;
}
sector.gap = gaps.ToArray();
// Return current position to be able to read separate sectors
endOffset = position;
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Got {0} bytes of gap", sector.gap.Length);
DicConsole.DebugWriteLine("Apple ][ GCR Decoder", "Finished sector at {0}", position);
return(sector);
}
if (data[position] == 0xFF)
{
position++;
}
// Found data that is not sync or a prologue
else
{
return(null);
}
}
}
catch (IndexOutOfRangeException) { return(null); }
return(null);
}