6502/CLK
1
0
Fork 0
mirror of https://github.com/TomHarte/CLK.git synced 2025-04-09 00:37:27 +00:00
Code Issues Projects Releases Wiki Activity

Fixed errors to ensure that FM disks, at least, follow the same CRC generation rules when being built from sectors and when being parsed.

Browse Source
This commit is contained in:
Thomas Harte 2016-12-28 19:48:46 -05:00
parent 1277a67f9a
commit 46a93d2e12
1 changed files with 25 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
Storage/Disk/Encodings/MFM.cpp
View File

@ -201,7 +201,9 @@ void Encoder::output_short(uint16_t value)
void Encoder::add_crc()
{
output_short(crc_generator_.get_value());
uint16_t crc_value = crc_generator_.get_value();
add_byte(crc_value >> 8);
add_byte(crc_value & 0xff);
}
std::shared_ptr<Storage::Disk::Track> Storage::Encodings::MFM::GetFMTrackWithSectors(const std::vector<Sector> &sectors)
@ -325,17 +327,25 @@ std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_next_sector()
while(shift_register_ == Storage::Encodings::MFM::MFMSync)
{
uint8_t mark = get_next_byte();
if(mark == Storage::Encodings::MFM::MFMIDAddressByte) break;
if(mark == Storage::Encodings::MFM::MFMIDAddressByte)
{
crc_generator_.set_value(MFMPostSyncCRCValue);
break;
}
}
}
else
{
if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) break;
if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark)
{
crc_generator_.reset();
break;
}
}
if(index_count_ >= 2) return nullptr;
}
crc_generator_.reset();
crc_generator_.add(MFMIDAddressByte);
sector->track = get_next_byte();
sector->side = get_next_byte();
sector->sector = get_next_byte();
@ -353,21 +363,29 @@ std::shared_ptr<Storage::Encodings::MFM::Sector> Parser::get_next_sector()
while(shift_register_ == Storage::Encodings::MFM::MFMSync)
{
uint8_t mark = get_next_byte();
if(mark == Storage::Encodings::MFM::MFMDataAddressByte) break;
if(mark == Storage::Encodings::MFM::MFMDataAddressByte)
{
crc_generator_.set_value(MFMPostSyncCRCValue);
break;
}
if(mark == Storage::Encodings::MFM::MFMIDAddressByte) return nullptr;
}
}
else
{
if(shift_register_ == Storage::Encodings::MFM::FMDataAddressMark) break;
if(shift_register_ == Storage::Encodings::MFM::FMDataAddressMark)
{
crc_generator_.reset();
break;
}
if(shift_register_ == Storage::Encodings::MFM::FMIDAddressMark) return nullptr;
}
if(index_count_ >= 2) return nullptr;
}
crc_generator_.add(MFMDataAddressByte);
size_t data_size = (size_t)(128 << size);
sector->data.reserve(data_size);
crc_generator_.reset();
for(size_t c = 0; c < data_size; c++)
{
sector->data.push_back(get_next_byte());