RF(4)                 NetBSD/vax Kernel Interfaces Manual                RF(4)

NAME
     rf -- DEC RX01 / RX02 floppy disk interface

SYNOPSIS
     rfc0 at uba? csr 0177170     # RX01/RX02 controller
     rf*  at rfc? drive?          # RX01/RX02 floppy disk drive

DESCRIPTION
     The rf device provides access to DEC RX01 and RX02 floppy disk drives and
     clones thereof.  These drives use preformatted 8" single sided, soft sec-
     tored media.  The RX01 and RX02 drives use a geometry of 77 cylinders,
     one head and 26 sectors.  Each sector contains 128 bytes in case of sin-
     gle density ( RX01 and RX02 in RX01 mode) or 256 bytes in double density
     mode.  As NetBSD is not able to handle non-512 byte media the driver
     translates this to a geometry of 50 cylinders, one head and 10 sectors in
     single density and 77 cylinders, one head and 13 sectors in double den-
     sity mode.  While the later matches the total number of sectors, the fake
     geometry in single density does not cover the last two physical sectors
     exact, but it is possible to access this sectors at 512 byte LBN 501.
     When a 512 byte block is written to LBN 501 the last 256 bytes are
     ignored.  When this 512 byte block is read the last 256 bytes contain
     undefined data.

     This driver supports three minor devices corresponding to the slices:

           Slice Description
           a     Single density only mode.
           b     Double density only mode.
           c     Density autodetect.

     As the RX01 and RX02 hardware is not able to support formatting a blank
     disk, this driver has no support for according IOCTLs.  But there are
     clones from third party vendors that support formatting.  Formatting a
     blank disk may be initiated by the following commands on the VAX chevron
     prompt:

           Single density
           d/p/w 20001E78 9
           d/p/w 20001E7A 92

           Double density
           d/p/w 20001E78 109
           d/p/w 20001E7A 92

FILES
     /dev/rf?[abc]
     /dev/rrf?[abc]

DIAGNOSTICS
     rfc_attach: Error creating bus_dma map: %d
     did not respond to INIT CMD  Possible errors during autoconf(4).  %d is
     the return code of bus_dmamap_create(9).

     %s: did not respond to CMD %x  An error occurred while the driver tried
     to send command %x to drive %s.

     rfc_intr: Error while reading sector: %x
     rfc_intr: Error while writing sector: %x
     rfc_intr: Error while DMA: %x  %x is status code from the controller
     error and status register.

     rfc_intr: Error while loading bus_dma map: %d  %d is return code of
     bus_dmamap_load(9).

     %s: density error.  A single density disk was opened in double density
     only mode or vice versa or the medium in the drive attached as %s was not
     readable at all.

SEE ALSO
     dd(1), tar(1), intro(4), disklabel(5), disklabel(8), mknod(8), mount(8),
     newfs(8)

HISTORY
     The rf driver appeared in NetBSD 2.0.  It is a complete rewrite, not
     related to the old 4.2BSD rx driver.

AUTHORS
     Jochen Kunz

BUGS
     Writing of a disklabel(5) is not supported.  The driver return always the
     internally fake disklabel.

NetBSD 5.0_STABLE               March 23, 2003               NetBSD 5.0_STABLE
