.trd file is a raw dump of TR-DOS (ZX-Spectrum) floppy. .trd files are headerless and contain consequent "logical tracks", each logical track consists of 16 256-byte sectors.
Logical tracks are defined the same way as used by TR-DOS: for single-side floppies it's just a physical track number, for two-side floppies sides are interleaved, i.e. logical_track_num = (physical_track_num << 1) | side
So, this format definition is more for TR-DOS filesystem than for .trd files, which are formatless.
Strings (file names, disk label, disk password) are padded with spaces and use ZX Spectrum character set, including UDGs, block drawing chars and Basic tokens. ASCII range is mostly standard ASCII, with few characters (^, `, DEL) replaced with (up arrow, pound, copyright symbol).
.trd file can be smaller than actual floppy disk, if last logical tracks are empty (contain no file data) they can be omitted.
This page hosts a formal specification of TR-DOS flat-file disk image using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = TrDosImage.from_file("path/to/local/file.trd")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = TrDosImage(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.files # => get files
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
from enum import Enum
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 9):
raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))
class TrDosImage(KaitaiStruct):
""".trd file is a raw dump of TR-DOS (ZX-Spectrum) floppy. .trd files are
headerless and contain consequent "logical tracks", each logical track
consists of 16 256-byte sectors.
Logical tracks are defined the same way as used by TR-DOS: for single-side
floppies it's just a physical track number, for two-side floppies sides are
interleaved, i.e. logical_track_num = (physical_track_num << 1) | side
So, this format definition is more for TR-DOS filesystem than for .trd files,
which are formatless.
Strings (file names, disk label, disk password) are padded with spaces and use
ZX Spectrum character set, including UDGs, block drawing chars and Basic
tokens. ASCII range is mostly standard ASCII, with few characters (^, `, DEL)
replaced with (up arrow, pound, copyright symbol).
.trd file can be smaller than actual floppy disk, if last logical tracks are
empty (contain no file data) they can be omitted.
"""
class DiskType(Enum):
type_80_tracks_double_side = 22
type_40_tracks_double_side = 23
type_80_tracks_single_side = 24
type_40_tracks_single_side = 25
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.files = []
i = 0
while True:
_ = TrDosImage.File(self._io, self, self._root)
self.files.append(_)
if _.is_terminator:
break
i += 1
class VolumeInfo(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.catalog_end = self._io.read_bytes(1)
if not self.catalog_end == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.catalog_end, self._io, u"/types/volume_info/seq/0")
self.unused = self._io.read_bytes(224)
self.first_free_sector_sector = self._io.read_u1()
self.first_free_sector_track = self._io.read_u1()
self.disk_type = KaitaiStream.resolve_enum(TrDosImage.DiskType, self._io.read_u1())
self.num_files = self._io.read_u1()
self.num_free_sectors = self._io.read_u2le()
self.tr_dos_id = self._io.read_bytes(1)
if not self.tr_dos_id == b"\x10":
raise kaitaistruct.ValidationNotEqualError(b"\x10", self.tr_dos_id, self._io, u"/types/volume_info/seq/7")
self.unused_2 = self._io.read_bytes(2)
self.password = self._io.read_bytes(9)
self.unused_3 = self._io.read_bytes(1)
self.num_deleted_files = self._io.read_u1()
self.label = self._io.read_bytes(8)
self.unused_4 = self._io.read_bytes(3)
@property
def num_tracks(self):
if hasattr(self, '_m_num_tracks'):
return self._m_num_tracks
self._m_num_tracks = (40 if (self.disk_type.value & 1) != 0 else 80)
return getattr(self, '_m_num_tracks', None)
@property
def num_sides(self):
if hasattr(self, '_m_num_sides'):
return self._m_num_sides
self._m_num_sides = (1 if (self.disk_type.value & 8) != 0 else 2)
return getattr(self, '_m_num_sides', None)
class PositionAndLengthCode(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.start_address = self._io.read_u2le()
self.length = self._io.read_u2le()
class Filename(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.name = self._io.read_bytes(8)
@property
def first_byte(self):
if hasattr(self, '_m_first_byte'):
return self._m_first_byte
_pos = self._io.pos()
self._io.seek(0)
self._m_first_byte = self._io.read_u1()
self._io.seek(_pos)
return getattr(self, '_m_first_byte', None)
class PositionAndLengthPrint(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.extent_no = self._io.read_u1()
self.reserved = self._io.read_u1()
self.length = self._io.read_u2le()
class PositionAndLengthGeneric(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.reserved = self._io.read_u2le()
self.length = self._io.read_u2le()
class PositionAndLengthBasic(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self.program_and_data_length = self._io.read_u2le()
self.program_length = self._io.read_u2le()
class File(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
self._io = _io
self._parent = _parent
self._root = _root if _root else self
self._read()
def _read(self):
self._raw_name = self._io.read_bytes(8)
_io__raw_name = KaitaiStream(BytesIO(self._raw_name))
self.name = TrDosImage.Filename(_io__raw_name, self, self._root)
self.extension = self._io.read_u1()
_on = self.extension
if _on == 66:
self.position_and_length = TrDosImage.PositionAndLengthBasic(self._io, self, self._root)
elif _on == 67:
self.position_and_length = TrDosImage.PositionAndLengthCode(self._io, self, self._root)
elif _on == 35:
self.position_and_length = TrDosImage.PositionAndLengthPrint(self._io, self, self._root)
else:
self.position_and_length = TrDosImage.PositionAndLengthGeneric(self._io, self, self._root)
self.length_sectors = self._io.read_u1()
self.starting_sector = self._io.read_u1()
self.starting_track = self._io.read_u1()
@property
def is_deleted(self):
if hasattr(self, '_m_is_deleted'):
return self._m_is_deleted
self._m_is_deleted = self.name.first_byte == 1
return getattr(self, '_m_is_deleted', None)
@property
def is_terminator(self):
if hasattr(self, '_m_is_terminator'):
return self._m_is_terminator
self._m_is_terminator = self.name.first_byte == 0
return getattr(self, '_m_is_terminator', None)
@property
def contents(self):
if hasattr(self, '_m_contents'):
return self._m_contents
_pos = self._io.pos()
self._io.seek((((self.starting_track * 256) * 16) + (self.starting_sector * 256)))
self._m_contents = self._io.read_bytes((self.length_sectors * 256))
self._io.seek(_pos)
return getattr(self, '_m_contents', None)
@property
def volume_info(self):
if hasattr(self, '_m_volume_info'):
return self._m_volume_info
_pos = self._io.pos()
self._io.seek(2048)
self._m_volume_info = TrDosImage.VolumeInfo(self._io, self, self._root)
self._io.seek(_pos)
return getattr(self, '_m_volume_info', None)