Apple double-density 3 1/2" disk
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| + | The '''Apple double-density 3 1/2" disk''' was used on the Macintosh (with the [[MFS]] or [[HFS]] file system) and the Apple II line (with the [[ProDOS file system]]). It was a disk format with 80 tracks per side and a variable 8 to 12 sectors per track, with each sector storing 512 bytes. When used in single-sided mode, its capacity was 400 kilobytes; this became 800 in double-sided mode. Data was encoded using a form of [[GCR encoding]]. The drive ran at constant linear velocity (CLV), meaning that the RPM rate varied depending on which track was being read. | ||
| − | The | + | The [[Apple high-density 3 1/2" disk]] is the high-density counterpart of this format, on higher-capacity physical media introduced later. |
| + | |||
| + | 3 1/2" disks are actually 90 mm wide, but are almost universally referred to as "3 1/2 inch" disks even in countries that use the metric system. | ||
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| + | == Links == | ||
| + | * [http://retro.icequake.net/apple2pc.html Apple-to-PC disk transfer info] | ||
| + | * [http://www.textfiles.com/uploads/apple2gscracks.txt Apple IIgs cracks] | ||
| + | * [http://www.bigmessowires.com/macintosh-floppy-emu/ Floppy Emu, a floppy disk emulator] | ||
| + | * [https://porterolsen.wordpress.com/2016/06/15/accessing-mac-formatted-floppy-disks-without-the-kryoflux/ Accessing Mac Formatted Floppy Disks without a Kryoflux] | ||
[[Category:Apple II series]] | [[Category:Apple II series]] | ||
[[Category:Macintosh]] | [[Category:Macintosh]] | ||
Latest revision as of 13:00, 16 June 2016
The Apple double-density 3 1/2" disk was used on the Macintosh (with the MFS or HFS file system) and the Apple II line (with the ProDOS file system). It was a disk format with 80 tracks per side and a variable 8 to 12 sectors per track, with each sector storing 512 bytes. When used in single-sided mode, its capacity was 400 kilobytes; this became 800 in double-sided mode. Data was encoded using a form of GCR encoding. The drive ran at constant linear velocity (CLV), meaning that the RPM rate varied depending on which track was being read.
The Apple high-density 3 1/2" disk is the high-density counterpart of this format, on higher-capacity physical media introduced later.
3 1/2" disks are actually 90 mm wide, but are almost universally referred to as "3 1/2 inch" disks even in countries that use the metric system.
