Table of Contentsfdrawcmd - send raw commands to the floppy disk controller rawcmd [drive=drive] [rate=rate] [length=length] [repeat=count] [seek=physical_track] command [parameters...] [mode] fdrawcmd is used to send raw commands to the floppy disk controller, after having selected a given drive. You must have write permission to the selected drive. When writing to a disk, data is read from stdin; when reading, data is printed to stdout. Diagnostic messages, return values from the controller, and the value of the disk change line after the command are printed to stderr.
All numbers may be given in octal (0209), decimal (137), or hexadecimal (0x89). - drive=drive
- Selects the drive. The default is drive 0
- rate=rate
- Selects the data transfer rate. Use 0 for high density disks, 1 for double density 5 1/4 disks (or 2 Mbps tapes, if the appropriate rate table is selected), and 2 for double density 3 1/2 disks.
- length=length
- Describes the length of the transferred data for commands reading from and writing to the disk. The default is to continue until EOF.
- repeat=count
- Repeat the command count times. This only works correctly for commands which don't do any data transfer.
- command
- The name of the command to send. command may be a spelled out name (like read or write), or a number. A named command has already a mode, whereas for a number the mode parameter should be described using the appropriate option.
- parameter
- The parameter for the command.
- mode
- Various flags or'ed together describing the properties of the command.
The description of the various floppy commands given in this manpage is very sketchy. For more details get the 82078 spec sheet which can be found at http://www-techdoc.intel.com/docs/periph/fd_contr/datasheets/. Look for the chapter COMMAND SET/DESCRIPTIONS. Older FDCs only support a subset of the commands described therein, but the syntax for the commands that do exist is the same. - read drivesel track head sector sizecode sect_per_track rw_gap sizecode2
- Reads length bytes of data from the disk. drivesel is the drive selector. Bit 0 and 1 describe the drive, and bit 2 describes the head. The remaining parameters give the track, head (yes, again), sector, size of the sector (128 * 2 ^ sizecode), sectors per track (used to switch to the second head when the first side has been read), and size of the read-write gap. sizecode2 should be 0xff. read returns ST0 ST1 ST2 and track head sector sizecode of the next sector to be read; see /usr/include/linux/fdreg.h.
- write drivesel track head sector sizecode sect_per_track rw_gap sizecode
- Analogous to read.
- sense drivesel
- Returns the third status byte
- recalibrate drivesel
- Recalibrates the drive and returns ST0 ST1.
- seek drivesel track
- Moves the head to track and returns ST0 ST1.
- specify drivesel spec1 spec2
- Specify various parameters to the drive.
- format drivesel sizecode sect_per_track fmt_gap fmt_fill
- Formats the track. The new sectors are filled with fmt_fill. The header information comes from the input, which is made up of track head sector sizecode quadruples. The sizecode parameter from the command line is used to describe the actual size of the sectors, and the sizecode from the input is used to write into the header. However, the first write to these sectors will use the header information, and might overwrite the following sectors if the sizecode parameter from the command line was too small.
- readid drivesel
- reads the first sector header that comes and returns ST0 ST1 ST2 and track head sector sizecode of the encountered header.
- dumpregs
- Prints the contents of the FDCs registers, if supported.
- configure conf1 conf2 conf3
- Configures FIFO operation.
- version
- Echoes 0x90 if the FDC is more recent than 82072A, and 0x80 otherwise
- perpendicular rate
- Sets the perpendicular mode. Use 0 for normal, 2 for 500Kbps perpendicular, and 3 for 1Mbps perpendicular.
- seek_out drivesel n
- does a relative seek of n tracks towards track 0.
- seek_in drivesel n
- does a relative seek of n tracks towards the high numbered track.
- lock
- Locks the FIFO configuration, so that it survives a FDC software reset.
- unlock
- Unlock the FIFO configuration
- partid
- echoes a byte describing the type of the FDC in the 3 high bits, and the stepping in the three low bits.
- powerdown powerconf
- configures automatic power down of the FDC. The old configuration is echoed
- option iso
- enables/disables ISO formats. Odd values of iso enable these formats, whereas even values disable them. ISO formats don't have index headers, and thus allow to fit slightly more data on a disk.
- save
- prints out 16 internal registers of the FDC.
- restore r1 r2 r3 ... r16
- restores the 16 internal registers of the FDC.
- format_n_write drivesel sizecode sect_per_track fmt_gap fmt_fill
- formats the track and writes initial data to it. The input data is made up of a sequence of headers (4 bytes) and data: header1 data1 header2 sector2 ... headern sectorn
- drivespec dspec1 dspec2 ... specn terminator
- chooses rate tables for various drives. Each dspec byte describes one drive. Bits 0 and 1 say which drive is described. Bits 2 and 3 describe the rate table. Only tables 0 and 2 are interesting. Both tables only differ in the meaning og rate 1. For table 0 (the default) rate 0 is 300 Kbps (used for 5 1/4 DD disks), whereas for table 1 it is 2 Mbps (used for fast floppy tape drives). Bit 4 is the precompensation table select bit. It should be set to 0. Bit 5-7 should be zero as well. The terminator byte ends the drivespec command. It is either 0xc0 or 0x80. If it is 0xc0, no result phase follows; if it is 0x80, the current data rate table configuration for the four drives is echoed.
The mode option is only needed when you describe the command as a numerical value. Some mode names are also valid command names. They are considered as command name if the command name has not yet been given, and as mode name otherwise. If you give a command name and an explicit mode, both the implicit flags of the command name, and the explicit mode are or'ed together. Several modes may be or'ed together too. - read
- Read data from disk using DMA.
- write
- Write data to the disk.
- intr
- Wait for an interrupt.
- spin
- wait for the disk to spin up
- need_seek
- Seeks the drives head to the correct track (as given by the seek parameter) before sending the command.
- disk
- Aborts the operation if no disk is in the drive. This only works if need_seek is also chosen.
- no_motor
- Don't switch on the drive motor while issuing the command
- no_motor_after
- Switch off the motor immediately after the command returns.
fdrawcmd opens the device node with the NDELAY flag. This means that the driver should not try to autodetect the disk type (it might not be formatted), and that it should not reset the FDC. If a reset was needed, the command simply fails. If that happens, execute floppycontrol --resetnow 0, and try again. /dev/fd* - Floppy devices Alain Knaff, Alain.Knaff@inrialpes.fr superformat(1), getfdprm(1), floppycontrol(1)
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