fluxengine/doc/disk-atarist.md

atarist

Almost PC compatible

Atari ST disks are standard MFM encoded IBM scheme disks without an IAM header. Disks are typically formatted 512 bytes per sector with between 9-10 (sometimes 11!) sectors per track and 80-82 tracks per side.

For some reason, occasionally formatting software will put an extra IDAM record with a sector number of 66 on a disk, which can horribly confuse things. The Atari profiles below are configured to ignore these.

Be aware that many PC drives (including mine) won't do the 82 track formats.

Options

• Format variants:
  • 360: 360kB 3.5" 80-track 9-sector SSDD
  • 370: 370kB 3.5" 82-track 9-sector SSDD
  • 400: 400kB 3.5" 80-track 10-sector SSDD
  • 410: 410kB 3.5" 82-track 10-sector SSDD
  • 720: 720kB 3.5" 80-track 9-sector DSDD
  • 740: 740kB 3.5" 82-track 9-sector DSDD
  • 800: 800kB 3.5" 80-track 10-sector DSDD
  • 820: 820kB 3.5" 82-track 10-sector DSDD

Examples

To read:

• fluxengine read -c atarist --360 -s drive:0 -o atarist.img
• fluxengine read -c atarist --370 -s drive:0 -o atarist.img
• fluxengine read -c atarist --400 -s drive:0 -o atarist.img
• fluxengine read -c atarist --410 -s drive:0 -o atarist.img
• fluxengine read -c atarist --720 -s drive:0 -o atarist.img
• fluxengine read -c atarist --740 -s drive:0 -o atarist.img
• fluxengine read -c atarist --800 -s drive:0 -o atarist.img
• fluxengine read -c atarist --820 -s drive:0 -o atarist.img

To write:

• fluxengine write -c atarist --360 -d drive:0 -i atarist.img
• fluxengine write -c atarist --370 -d drive:0 -i atarist.img
• fluxengine write -c atarist --400 -d drive:0 -i atarist.img
• fluxengine write -c atarist --410 -d drive:0 -i atarist.img
• fluxengine write -c atarist --720 -d drive:0 -i atarist.img
• fluxengine write -c atarist --740 -d drive:0 -i atarist.img
• fluxengine write -c atarist --800 -d drive:0 -i atarist.img
• fluxengine write -c atarist --820 -d drive:0 -i atarist.img

References

• Atari ST Floppy Drive Hardware Information by Jean Louis-Guerin

• Atari ST Floppy Drive Software Information by Jean Louis-Guerin