iwm(4) - NetBSD Manual Pages

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IWM(4)              NetBSD/mac68k Kernel Interfaces Manual              IWM(4)


NAME

     iwm, fd -- floppy disk driver for IWM and non-DMA SWIM controllers


SYNOPSIS

     iwm0 at obio?
     fd* at iwm0 drive ?


DESCRIPTION

     The iwm driver interfaces to the built-in and external floppy disk drives
     on the Macintosh. It supports double-density media, written in Apple's
     proprietary GCR format. Currently, there is no disklabel support for the
     floppy drives. Instead, the iwm driver sets up a fake in-core disklabel,
     using the minor device number to select from the supported disk formats.

     The following formats are supported:

     Partition   Size   sides   tracks   sectors/track
     a           800Kb  2       80       10 (default)
     b           400Kb  1       80       10
     c           800Kb  2       80       10

     (The above table describes the logical mapping as implemented by the
     driver; the physical layout of GCR floppies has 8..12 sectors per track.)


FORMATTING

     The iwm driver does currently not support floppy disk formatting.


SEE ALSO

     Apple Computer, Inc.: "Inside Macintosh", Vol III-33f. (Addison-Wesley)

     Apple Computer, Inc.: "New Technical Notes DV 17 - Sony Driver"

     Neil Parker: "iwmstuff"

     eject(1)


HISTORY

     The iwm interface first appeared in NetBSD 1.4.


AUTHORS

     Hauke Fath put together the beginnings of the iwm driver in 1996 from the
     sparse documentation in "Inside Macintosh", Neil Parker's "iwmstuff" doc-
     umentation for the Apple IIgs and a long, hard look at the .Sony driver.


BUGS

     The FFS code is incapable of dealing with a varying number of sectors per
     track. We have to fake a mapping and so lose FFS support for hardware
     parameters like transition times.

     The driver only supports an obsolete format.

NetBSD 6.1                       June 6, 1998                       NetBSD 6.1