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acornadfs

BBC Micro, Archimedes

Acorn ADFS disks are used by the 6502-based BBC Micro and ARM-based Archimedes series of computers. They are yet another variation on MFM encoded IBM scheme disks, although with different sector sizes and with the 0-based sector identifiers rather than 1-based sector identifiers. The index hole is ignored and sectors are written whereever, requiring FluxEngine to do two revolutions to read a disk.

There are various different kinds, which should all work out of the box.

Be aware that Acorn logical block numbering goes all the way up side 0 and then all the way up side 1. However, FluxEngine uses traditional disk images with alternating sides, with the blocks from track 0 side 0 then track 0 side 1 then track 1 side 0 etc. Most Acorn emulators will use both formats, but they might require nudging as the side order can't be reliably autodetected.

Options

  • Format variants:
    • 160: 160kB 3.5" or 5.25" 40-track SSDD; S format
    • 320: 320kB 3.5" or 5.25" 80-track SSDD; M format
    • 640: 640kB 3.5" or 5.25" 80-track DSDD; L format
    • 800: 800kB 3.5" 80-track DSDD; D and E formats
    • 1600: 1600kB 3.5" 80-track DSHD; F formats

Examples

To read:

  • fluxengine read acornadfs --160 -s drive:0 -o acornadfs.img
  • fluxengine read acornadfs --320 -s drive:0 -o acornadfs.img
  • fluxengine read acornadfs --640 -s drive:0 -o acornadfs.img
  • fluxengine read acornadfs --800 -s drive:0 -o acornadfs.img
  • fluxengine read acornadfs --1600 -s drive:0 -o acornadfs.img