// convert the 256 8-bit bytes into 342 6-bit bytes
// argument nSector is Logical Sector.(by dos order)
void CDiskImageDos::Code62(int nSector)
{
int i;
{
BYTE* pbyPage = m_abyDosBuffer + ( nSector << 8 );
BYTE offset = 0xAC;
i = 0;
while ( offset != 0x02 )
{
BYTE value = 0;
#define ADDVALUE(a) \
value = (value << 2 ) | (((a) & 0x01) << 1 ) | (((a) & 0x02) >> 1)
ADDVALUE(pbyPage[offset]); offset -= 0x56;
ADDVALUE(pbyPage[offset]); offset -= 0x56;
ADDVALUE(pbyPage[offset]); offset -= 0x53;
#undef ADDVALUE
m_abyGcrBuffer[i++] = value << 2;
}
// i = 256 / 3 = 86 ( last 2 byte is only 4 bit )
// clear off higher 2 bits of the last 2 byte
m_abyGcrBuffer[84] &= 0x3F;
m_abyGcrBuffer[85] &= 0x3F;
memcpy( m_abyGcrBuffer + 86, pbyPage, 256 );
m_abyGcrBuffer[342] = 0;
}
// exclusive-or the entire data block with itself offset by one byte
{
i = 342;
while( i-- )
m_abyGcrBuffer[i+1] ^= m_abyGcrBuffer[i];
}
{
for( i = 0; i < 343; i++ )
WriteNibble( sm_abyGcrEncTable[ m_abyGcrBuffer[i] >> 2 ] );
}
}
int GmMemoryOutStream::AddByte8 (const byte8 & value)
{
ADDVALUE (byte8, value, Byte8ToChars);
}
int GmMemoryOutStream::AddByte2 (const byte2 & value)
{
ADDVALUE (byte2, value, Byte2ToChars);
}
int GmMemoryOutStream::AddByte4 (const byte4 & value)
{
ADDVALUE (byte4, value, Byte4ToChars);
}
