Magcard Write Read Utility Program -

def is_valid_track(self, track_num, data): if track_num == 1: return all(ch in TRACK1_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[1] elif track_num == 2: return all(ch in TRACK2_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[2] elif track_num == 3: return all(ch in TRACK3_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[3] return False

def read_track(self, track_num): if track_num == 1: return self.track1 elif track_num == 2: return self.track2 elif track_num == 3: return self.track3 else: raise ValueError("Track must be 1, 2, or 3") magcard write read utility program

def clear(self): self.track1 = "" self.track2 = "" self.track3 = "" def encode_track(data, start_sentinel='%', end_sentinel='?'): """Adds start/end sentinels and LRC (simple XOR checksum)""" lrc = 0 for ch in data: lrc ^= ord(ch) checksum_char = chr(lrc % 128) # simple printable approximation return f"start_sentineldataend_sentinelchecksum_char" python magcard_util

For example, a USB keyboard wedge reader would just capture swiped data as if typed – no special driver needed. A writer would require sending track data in a proprietary command format over USB HID or serial. data): if not self.is_valid_track(track_num

For real hardware (e.g., MagTek, ID Tech readers), you would replace the simulated I/O with serial/USB HID commands.

python magcard_util.py --write "2:1234567890" Read track 1:

def write_track(self, track_num, data): if not self.is_valid_track(track_num, data): raise ValueError(f"Invalid data for track track_num. Length or character mismatch.") if track_num == 1: self.track1 = data elif track_num == 2: self.track2 = data elif track_num == 3: self.track3 = data else: raise ValueError("Track must be 1, 2, or 3")