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51 lines
1.9 KiB
Markdown
51 lines
1.9 KiB
Markdown
northstar
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====
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## 5.25" hard sectored
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<!-- This file is automatically generated. Do not edit. -->
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Northstar Floppy disks use 10-sector hard sectored disks with either FM or MFM
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encoding. They may be single- or double-sided. Each of the 10 sectors contains
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256 (FM) or 512 (MFM) bytes of data. The disk has 35 cylinders, with tracks 0-
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34 on side 0, and tracks 35-69 on side 1. Tracks on side 1 are numbered "back-
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wards" in that track 35 corresponds to cylinder 34, side 1, and track 69
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corresponds to cylinder 0, side 1.
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The Northstar sector format does not include any head positioning information.
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As such, reads from Northstar floppies need to by synchronized with the index
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pulse, in order to properly identify the sector being read. This is handled
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automatically by FluxEngine.
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Due to the nature of the track ordering on side 1, an .nsi image reader and
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writer are provided for double-sided disks. The .nsi image writer supports
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both single- and double-sided disks; however single-sided .nsi images are
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equivalent to .img images.
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## Options
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- Format variants:
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- `87`: 87.5kB 5.25" 35-track SSSD hard-sectored
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- `175`: 175kB 5.25" 40-track SSDD hard-sectored
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- `350`: 350kB 5.25" 40-track DSDD hard-sectored
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## Examples
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To read:
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- `fluxengine read -c northstar --87 -s drive:0 -o northstar.nsi`
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- `fluxengine read -c northstar --175 -s drive:0 -o northstar.nsi`
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- `fluxengine read -c northstar --350 -s drive:0 -o northstar.nsi`
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To write:
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- `fluxengine write -c northstar --87 -d drive:0 -i northstar.nsi`
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- `fluxengine write -c northstar --175 -d drive:0 -i northstar.nsi`
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- `fluxengine write -c northstar --350 -d drive:0 -i northstar.nsi`
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## References
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- [MICRO-DISK SYSTEM MDS-A-D DOUBLE DENSITY Manual][northstar_mds].
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Page 33 documents sector format for single- and double-density.
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[northstar_mds]: http://bitsavers.org/pdf/northstar/boards/Northstar_MDS-A-D_1978.pdf
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