FDC(4) | Device Drivers Manual (amiga) | FDC(4)

# 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), amiga/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.

February 17, 2017 | NetBSD 11.0