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.\" @(#)rx.4 6.2 (Berkeley) 3/27/91
.Cd "controller fx0 at uba0 csr 0177170 vector rxintr"
.Cd "disk rx0 at fx0 drive 0"
.Cd "disk rx1 at fx0 drive 1"
device provides access to a
unit with M8256 interface module
uses 8-inch, single-sided, soft-sectored floppy
disks (with pre-formatted industry-standard headers) in
either single or double density.
Floppy disks handled by the
contain 77 tracks, each with 26
sectors (for a total of 2,002 sectors). The sector size is 128
bytes for single density, 256 bytes for double density. Single
density disks are compatible with the
floppy disk unit and with
3740 Series Diskette 1 systems.
In addition to normal (`block' and `raw')
formatting of disks for either density and
the ability to invoke a 2 for 1 interleaved sector mapping
The minor device number is interpreted as follows:
.Bl -column Otherx -offset indent
0 Sector interleaving (1 disables interleaving)
1 Logical sector 1 is on track 1 (0 no, 1 yes)
The two drives in a single
two disks attached to a single controller. Thus, if there are two
on a system, the drives on the first
while the drives on the second are
When the device is opened, the density of the disk
currently in the drive is automatically determined. If there
is no floppy in the device, open will fail.
The interleaving parameters are represented in raw device
called by one of the following names:
.Bl -column interleavedxx "Device namexx" "Starting Track" -offset indent
.Sy Mapping Device name Starting track
device is compatible with the
sectors of the disk in strictly sequential order.
device is the most efficient for disk-to-disk copying.
This mapping is always used by the block device.
requests must start on a sector boundary, involve an integral
number of complete sectors, and not go off the end of the disk.
Even though the storage capacity on a floppy disk is quite
small, it is possible to make filesystems on
.Bd -literal -offset indent
% mkfs /dev/rx0 1001 13 1 4096 512 32 0 4
makes a file system on the double density disk in rx0 with
436 kbytes available for file storage.
gives a more efficient utilization of the available
Single density diskettes do not provide sufficient storage capacity to
calls apply to the rx devices, and
.Bd -literal -offset indent
#include <vaxuba/rxreg.h>
The applicable codes are:
.Bl -tag -width RXIOC_GETDENS
Format the diskette. The density to use is specified
argument, zero gives single density while non-zero
Return the density of the diskette (zero or non-zero as above).
On the next write, include a
.Em deleted data address mark
the header of the first sector.
Return non-zero if the last sector read contained a
.Em deleted data address mark
.Bl -tag -width /dev/rx?xx -compact
.It "rx%d: hard error, trk %d psec %d cs=%b, db=%b, err=%x, %x, %x, %x."
An unrecoverable error was encountered. The
track and physical sector numbers, the device registers and the
extended error status are displayed.
.It rx%d: state %d (reset).
The driver entered a bogus state. This should not happen.
The following errors may be returned by the driver:
Drive not ready; usually because no disk is in the drive or
Nonexistent drive (on open);
offset is too large or not on a sector boundary or
byte count is not a multiple of the sector size (on read or write);
or bad (undefined) ioctl code.
A physical error other than ``not ready'', probably bad media or
Drive has been opened for exclusive access.
No write access (on format), or wrong density; the latter
can only happen if the disk is changed without
A floppy may not be formatted if the
header info on sector 1, track 0 has been damaged. Hence, it is not
possible to format completely degaussed disks or disks with other
formats than the two known by the hardware.
If the drive subsystem is powered down when the machine is booted, the
controller won't interrupt.
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