// JV1
private static FloppyData FromJV1(byte[] DiskData)
{
const byte SECTORS_PER_TRACK = 10;
const int SECTOR_LENGTH = 0x100;
if (DiskData.Length % (SECTOR_LENGTH * SECTORS_PER_TRACK) != 0)
{
throw new Exception("Invalid JV1 Format");
}
var sectors = new List <SectorDescriptor>();
byte numTracks = (byte)(DiskData.Length / 0x100 / 0x0A);
// Sectors not interleaved
for (byte i = 0; i < numTracks; i++)
{
for (byte j = 0; j < SECTORS_PER_TRACK; j++)
{
var sd = new SectorDescriptor(i, j, false, false, (i == 17) ? DAM_DELETED : DAM_NORMAL, new byte[SECTOR_LENGTH], true, false, false);
Array.Copy(DiskData, (i * SECTORS_PER_TRACK + j) * SECTOR_LENGTH, sd.SectorData, 0, SECTOR_LENGTH);
sectors.Add(sd);
}
}
return(new FloppyData(sectors, false));
}
private const byte JV3_SECTOR_FREE_FLAGS = 0xFC; // in flags field, OR'd with size code
// JV3
private static FloppyData FromJV3(byte[] DiskData)
{
var sectors = new List <SectorDescriptor>();
int diskCursor = 0;
bool?writeProt = null;
while (diskCursor < DiskData.Length - JV3_HEADER_SIZE - 1)
{
// Read sector Headers
for (int i = diskCursor; i < diskCursor + JV3_HEADER_SIZE; i += 3)
{
if (DiskData[i] != JV3_SECTOR_FREE && DiskData[i + 1] != JV3_SECTOR_FREE) // 0xFF for unused header entries
{
byte flags = DiskData[i + 2];
bool dd = (flags & JV3_DOUBLE_DENSITY) == JV3_DOUBLE_DENSITY;
var inUse = (flags & JV3_SECTOR_FREE_FLAGS) != JV3_SECTOR_FREE_FLAGS;
// Sector Size Codes
// Size IBM size SECTOR_SIZE field SECTOR_SIZE field
// code if in use if free
// 0x080 00 1 2
// 0x100 01 0 3
// 0x200 02 3 0
// 0x400 03 2 1
// JV3 sector size code is stored in a weird way
var sectorSizeCode = (byte)((flags & JV3_SECTOR_SIZE_MASK) ^ (inUse ? 1 : 2));
var sectorSize = GetDataLengthFromCode(sectorSizeCode);
var sd = new SectorDescriptor(DiskData[i],
DiskData[i + 1],
(flags & JV3_SIDE_ONE) == JV3_SIDE_ONE,
dd,
GetDamFromJV3Flags(flags, dd),
new byte[sectorSize],
inUse,
(flags & JV3_CRC_ERROR) == JV3_CRC_ERROR,
(flags & JV3_NON_IBM) == JV3_NON_IBM);
sectors.Add(sd);
}
}
diskCursor += JV3_HEADER_SIZE;
if (writeProt.HasValue)
{
diskCursor++;
}
else
{
writeProt = (DiskData[diskCursor++] != 0xFF);
}
foreach (var sd in sectors)
{
if (sd.InUse)
{
if (DiskData.Length - diskCursor < sd.SectorSize) // not enough data for sector
{
if (DiskData.Length > diskCursor) // try to get some data
{
Array.Copy(DiskData, diskCursor, sd.SectorData, 0, DiskData.Length - diskCursor);
}
diskCursor = DiskData.Length; // push cursor past end; we're done
}
else
{
Array.Copy(DiskData, diskCursor, sd.SectorData, 0, sd.SectorSize);
}
}
diskCursor += sd.SectorSize;
}
}
return(new FloppyData(sectors, writeProt.Value));
}