NAME

fdc — Amiga custom chip floppy disk controller device

SYNOPSIS

fdc0 at mainbus0
fd* at fdc? unit ?

DESCRIPTION

The fdc device driver provides support for the mainboard floppy disk controller and floppy disk drives on Amiga systems.

The driver supports the following floppy diskette formats by using particular partitions:

880KB 3.5-inch 11 sectors/track (``Amiga'') (a)

1.76MB 3.5-inch 22 sectors/track (``Amiga'') (a)

880KB 5.25-inch 11 sectors/track (``Amiga'') (a)

720KB 3.5-inch 9 sectors/track (``MS-DOS'') (b)

1.44MB 3.5-inch 18 sectors/track (``MS-DOS'') (b)

720KB 5.25-inch 9 sectors/track (``MS-DOS'') (b)

On systems equipped with floppy disk drives capable of using high-density floppy diskettes, the driver automatically detects whether the inserted floppy diskette is either a double-density or a high-density medium.

DIAGNOSTICS

fdc: unable to allocate DMA buffer

The driver found the controller, but was unable to allocate the amount of chip memory required for its DMA buffers.

SEE ALSO

fdformat(1), autoconf(4)

BUGS

In order to detect a floppy disk drive's capability of using high-density media, a high-density diskette has to be inserted for the duration of the autoconfiguration phase of the drive.

The fdc driver supports neither the fdformat(1) facility nor the <sys/fdio.h> interface.