public static TAPBlock LoadBlock(byte[] FileData, int StartPos, out int EndPos)
{
EndPos = 0;
TAPBlock block = new TAPBlock();
block.Length = Word(FileData, StartPos);
if (block.Length + StartPos + 2 > FileData.Length)
{
return(null);
}
block.Data = new byte[block.Length];
Buffer.BlockCopy(FileData, StartPos + 2, block.Data, 0, block.Data.Length);
EndPos = StartPos + 2 + block.Length;
return(block);
}
public static TAPFile Load(string FileName)
{
TAPFile file = new TAPFile();
byte[] data = File.ReadAllBytes(FileName);
List <TAPBlock> blocks = new List <TAPBlock>();
int pos = 0;
while (pos < data.Length)
{
TAPBlock block = TAPBlock.LoadBlock(data, pos, out pos);
if (block == null)
{
return(null);
}
blocks.Add(block);
}
byte[] basicLoader = null;
while (blocks.Count > 0)
{
if (blocks.Count < 2)
{
return(null);
}
TAPBlock headerBlock = blocks[0];
blocks.RemoveAt(0);
TAPBlock dataBlock = blocks[0];
blocks.RemoveAt(0);
if (!headerBlock.IsHeader || dataBlock.IsHeader ||
!headerBlock.IsValid || !dataBlock.IsValid)
{
return(null);
}
TAPHeader realHeader = headerBlock.GetHeader();
byte[] realData = dataBlock.GetData();
if (realHeader.Type == TAPSpectrumDataType.Program)
{
if (basicLoader != null)
{
return(null);
}
basicLoader = realData;
}
else if (realHeader.Type == TAPSpectrumDataType.Code)
{
if (realHeader.Length != realData.Length)
{
return(null);
}
Buffer.BlockCopy(realData, 0, file.Data, realHeader.Param1, realData.Length);
if (realHeader.Param1 < file.StartAddress)
{
file.StartAddress = realHeader.Param1;
}
if (realHeader.Param1 + realData.Length > file.EndAddress)
{
file.EndAddress = realHeader.Param1 + realData.Length;
}
}
else
{
return(null);
}
}
if (basicLoader == null)
{
return(null);
}
file.Header = FindEntryPoint(basicLoader);
if (file.Header == null)
{
return(null);
}
return(file);
}
