Module disk525

Apple 5.25 inch disk module

This handles bit-level processing of a 5.25 inch GCR disk track. The logic state sequencer is approximated by a simple model.

Acknowledgment: some of this module is adapted from CiderPress.

Structs

• SectorAddressFormat
  How to find and read the sector address fields
• SectorDataFormat
  How to find and read the sector data
• TrackBits
  This is the main interface for interacting with 5.25 inch disk tracks. Writing to the track is at the bit stream level, any bit pattern will be accepted. Reading can be done by direct bit stream consumption, or through a soft latch. This will also behave as a cyclic buffer to reflect a circular track.

Constants

• DISK_BYTES_53
• DISK_BYTES_62

Functions

• create_std13_track
  Convenient form of create_track for compatibility with DOS 3.0, 3.1, and 3.2
• create_std16_track
  Convenient form of create_track for compatibility with DOS 3.3 and ProDOS
• create_track
  This creates a WOZ track including sync bytes, address fields, nibbles, checksums, etc.. The returned tuple has (track buffer, TrackBits object) For 13 sector disks, data segments are filled with high bits. For 16 sector disks, the data segment is created, and the data itself is zeroed.
• decode_44
  decode two bytes, returning the nibbles in a single u8
• format
  This creates a NIB or WOZ track including sync bytes, address fields, nibbles, checksums, etc.. The returned tuple has (track buffer, TrackBits object) For 13 sector disks, data segments are filled with high bits. For 16 sector disks, the data segment is created, and the data itself is zeroed. sync_bits = 8 for NIB, 9 for WOZ 13 sector, 10 for WOZ 16 sector. Track is padded to buf_len with 0x00 for WOZ, 0xFF for NIB.
• format_std13_track
  Convenient form of format for compatibility with DOS 3.0, 3.1, and 3.2
• format_std16_track
  Convenient form of format for compatibility with DOS 3.3 and ProDOS