fluxengine/src/formats/acornadfs.textpb

shortname: "Acorn ADFS"
comment: 'BBC Micro, Archimedes'
read_support_status: DINOSAUR

documentation:
<<<
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.
>>>

image_writer {
	filename: "acornadfs.img"
	type: IMAGETYPE_IMG
}

decoder {
	ibm {
		trackdata {
			ignore_side_byte: true
		}
	}
}

option_group {
	comment: "$formats"

	option {
		name: "160"
		comment: '160kB 3.5" or 5.25" 40-track SSDD; S format'

		config {
			layout {
				format_type: FORMATTYPE_40TRACK
				tracks: 40
				sides: 1
				layoutdata {
					sector_size: 256
					physical {
						start_sector: 0
						count: 16
					}
				}
			}
		}
	}

	option {
		name: "320"
		comment: '320kB 3.5" or 5.25" 80-track SSDD; M format'

		config {
			layout {
				format_type: FORMATTYPE_80TRACK
				tracks: 80
				sides: 1
				layoutdata {
					sector_size: 256
					physical {
						start_sector: 0
						count: 16
					}
				}
			}
		}
	}

	option {
		name: "640"
		comment: '640kB 3.5" or 5.25" 80-track DSDD; L format'

		config {
			layout {
				format_type: FORMATTYPE_80TRACK
				tracks: 80
				sides: 2
				layoutdata {
					sector_size: 256
					physical {
						start_sector: 0
						count: 16
					}
				}
			}
		}
	}

	option {
		name: "800"
		comment: '800kB 3.5" 80-track DSDD; D and E formats'

		config {
			layout {
				format_type: FORMATTYPE_80TRACK
				tracks: 80
				sides: 2
				layoutdata {
					sector_size: 1024
					physical {
						start_sector: 0
						count: 5
					}
				}
			}
		}
	}

	option {
		name: "1600"
		comment: '1600kB 3.5" 80-track DSHD; F formats'
		set_by_default: true

		config {
			layout {
				format_type: FORMATTYPE_80TRACK
				tracks: 80
				sides: 2
				layoutdata {
					sector_size: 1024
					physical {
						start_sector: 0
						count: 10
					}
				}
			}
		}
	}
}