/// <summary>
/// Does a "format" of the cyl/head/sec specified by the controller registers.
/// Does NOT commit to disk, only in memory copy is affected.
/// </summary>
private void FormatBlock()
{
HardDiskSector sectorData = new HardDiskSector(_cylinder, _head, _sector, _disk.DiskGeometry);
int dataAddr = _dataBufferLow | (_dataBufferHigh << 16);
int headerAddr = _headerAddressLow | (_headerAddressHigh << 16);
for (int i = 0; i < sectorData.Data.Length; i += 2)
{
int word = Memory.MemoryBoard.Instance.FetchWord(dataAddr + (i >> 1));
sectorData.Data[i] = (byte)(word & 0xff);
sectorData.Data[i + 1] = (byte)((word & 0xff00) >> 8);
}
// Write the new header data...
for (int i = 0; i < sectorData.Header.Length; i += 2)
{
int word = Memory.MemoryBoard.Instance.FetchWord(headerAddr + (i >> 1));
sectorData.Header[i] = (byte)(word & 0xff);
sectorData.Header[i + 1] = (byte)((word & 0xff00) >> 8);
}
// Write the sector to the disk...
_disk.SetSector(sectorData, _cylinder, _head, _sector);
#if TRACING_ENABLED
if (Trace.TraceOn)
{
Trace.Log(LogType.HardDisk,
"Shugart sector format of {0}/{1}/{2} complete, read from memory at {3:x5}",
_cylinder, _head, _sector, dataAddr);
}
#endif
SetBusyState();
}
/// <summary>
/// Does a read from the cyl/head/sec specified by the controller registers.
/// </summary>
private void ReadBlock()
{
// Read the sector from the disk...
HardDiskSector sectorData = _disk.GetSector(_cylinder, _head, _sector);
int dataAddr = _dataBufferLow | (_dataBufferHigh << 16);
int headerAddr = _headerAddressLow | (_headerAddressHigh << 16);
// Copy the data to the data buffer address
// and the header to the header address
for (int i = 0; i < sectorData.Data.Length; i += 2)
{
int word = sectorData.Data[i] | (sectorData.Data[i + 1] << 8);
MemoryBoard.Instance.StoreWord(dataAddr + (i >> 1), (ushort)word);
}
for (int i = 0; i < sectorData.Header.Length; i += 2)
{
int word = sectorData.Header[i] | (sectorData.Header[i + 1] << 8);
MemoryBoard.Instance.StoreWord(headerAddr + (i >> 1), (ushort)word);
}
#if TRACING_ENABLED
if (Trace.TraceOn)
{
Trace.Log(LogType.HardDisk,
"Shugart sector read complete from {0}/{1}/{2}, wrote to memory at {3:x5}",
_cylinder, _head, _sector, dataAddr);
}
#endif
SetBusyState();
}
/// <summary>
/// Does a write to the cyl/head/sec specified by the controller registers.
/// Does NOT commit to disk, only in memory copy is affected.
/// </summary>
private void WriteBlock(bool writeHeader)
{
HardDiskSector sectorData = new HardDiskSector(_cylinder, _head, _sector, _disk.DiskGeometry);
int dataAddr = _dataBufferLow | (_dataBufferHigh << 16);
int headerAddr = _headerAddressLow | (_headerAddressHigh << 16);
for (int i = 0; i < sectorData.Data.Length; i += 2)
{
int word = Memory.MemoryBoard.Instance.FetchWord(dataAddr + (i >> 1));
sectorData.Data[i] = (byte)(word & 0xff);
sectorData.Data[i + 1] = (byte)((word & 0xff00) >> 8);
}
if (writeHeader)
{
for (int i = 0; i < sectorData.Header.Length; i += 2)
{
int word = Memory.MemoryBoard.Instance.FetchWord(headerAddr + (i >> 1));
sectorData.Header[i] = (byte)(word & 0xff);
sectorData.Header[i + 1] = (byte)((word & 0xff00) >> 8);
}
}
else
{
// Keep the original header data.
HardDiskSector origSector = _disk.GetSector(_cylinder, _head, _sector);
origSector.Header.CopyTo(sectorData.Header, 0);
}
// Write the sector to the disk...
_disk.SetSector(sectorData, _cylinder, _head, _sector);
#if TRACING_ENABLED
if (Trace.TraceOn)
{
Trace.Log(LogType.HardDisk,
"Shugart sector write complete to {0}/{1}/{2}, read from memory at {3:x5}",
_cylinder, _head, _sector, dataAddr);
}
#endif
SetBusyState();
}
