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dskutil(1)			   Emulators			    dskutil(1)

       dskutil - Simple	sector edtor for discs and disc	images.

       dskutil	[-type TYPE] [-side SIDE] [-comp COMP] [-dstep]	[-retry	COUNT]
       [-format	FMT] DISKIMAGE
       dskutil is an interactive command-driven	sector editor, patterned after
       the  venerable  CP/M  sector editor DU90. This explains some of its id-
       iosyncracies, such as the fact that commands deal in logical track num-
       bers but	physical sector	numbers.

       -type TYPE
	      Determines which LibDsk driver is	to be used to access the disc.

	      auto    Select according to the disc image file. This is the de-

	      dsk     Use the DSK (CPCEmu format) image	driver.

	      edsk    Use the extended version of the DSK format.

	      floppy  Use the floppy driver.

	      myz80   Use the hard disk	(MYZ80 format)	image  driver.	 (This
		      format cannot be autodetected.)

	      cfi     Use  the	CFI  (DOS  fdcopy format) image	driver.	 (This
		      format cannot be autodetected.)

		      Use the ApriDisk image driver (from the utility  of  the
		      same name).  (This format	cannot be autodetected.)

	      raw     Use the raw driver.

       -comp COMP
	      Select  the  compression method used on the disc image file (has
	      no effect	when reading a floppy disc).

	      auto    Detect from the first few	bytes of the file. This	is the

	      sq      Huffman coded (SQ	/ USQ).

	      gz      Gzipped (gzip / gunzip).

	      bz2     Burrows-Wheeler compressed (bzip2	/ bunzip2).

       -side SIDE
	      Determines  which	 side  (0  or  1)  of the source disc is to be
	      scanned. If this option  is  not	present	 both  sides  will  be

       -dstep Double-step  the	source drive (used to read 360k	discs in 1.2Mb
	      drives). Only supported by the Linux floppy driver.

       -retry COUNT
	      Set the number of	times to attempt a read/write/format  in  case
	      of error.

       -format FMT
	      Do  not  autodetect  the	disc format; use the named format. The
	      format need only be an approximation to the actual  format  used
	      by the disc.

       -first CYL
	      Start scanning at	the specified cylinder.

       -last CYL
	      Scan up to and including the specified cylinder.

       The  following  single-letter  commands	are used. Operands in brackets
       such as [filename] are optional.	Numeric	inputs are  shown  as  nn  for
       decimal,	 and xx	for hex. In either case, prefixing the number with "#"
       selects the alternate number system.

       Multiple	commands on a line are allowed,	separated by semicolons.

       +[x]   Increase the current sector number by [x]	and read the resulting
	      sector, incrementing the track if	necessary.

       -[x]   Decrease the current sector number by [x]	and read the resulting
	      sector, decrementing the track if	necessary.

       #      Display the disc geometry	for the	current	drive/disc image.

	      View and amend the geometry. "$" by itself  shows	 all  possible
	      variables	with their current values; "$variable" shows the value
	      of one variable; and "$variable=value" sets a  new  value.  Note
	      that  changing  the  size	 of the	sector with "$secsize=nn" will
	      cause the	current	sector buffer and clip buffer to be cleared.

       =ascii Search for an ASCII string, starting at the current sector.  Hex
	      codes  can be included in	the ASCII by surrounding them with an-
	      gle brackets - for example, to search for	the  word  "Hello"  at
	      the  start  of  a	 line,	you could use "=<0A>Hello". The	search
	      string is	case-sensitive.

       <      Save the currently-loaded	sector to a clip buffer.

       >      Restore the contents of the clip buffer to  the  current	sector

       ?      Display a	command	summary.

	      Dump  the	contents of the	sector buffer as ASCII.	If from	and to
	      are included, then only values between  those  offsets  will  be

	      Change bytes in the current sector buffer. The offset and	values
	      are in hex.

	      Replace bytes in the current sector buffer with an ASCII string.
	      As  with	the  "="  command,  the	ASCII can contain embedded hex
	      bytes in angle brackets.

	      The same as CH above, but	fills the range	from from to  to  with
	      the byte sequence, repeating or truncating it as necessary.

	      The  same	 as CHfrom-to, except that the byte sequence is	speci-
	      fied as ASCII.

	      Dump the contents	of the sector buffer as	ASCII and hex.

       Gxx    Go to logical sector number xx

	      Dump the contents	of the sector buffer as	hex.

	      Save all "yanked"	sectors	(see Y below) to the  specified	 file.
	      This also	clears them from memory.

	      Open  a  new drive or disc image.	If this	has a different	sector
	      size from	the current sector size, the sector  buffer  and  clip
	      buffer will be cleared.

	      Change geometry. N by itself re-runs the automatic probe;	N with
	      the name of a geometry selects  one  of  the  formats  known  to

       R      (Re)read the current sector.

       Snn    Set the current sector number, and read.

       Tnn    Set the current track number. Does not read.

       V      Compare  the contents of the sector buffer with the current sec-
	      tor on disc.

       W      Write the	sector buffer to disc.

       X      Leave dskutil.

       Y      Append the current sector	to a "yank" buffer.  It	 can  then  be
	      saved with the K command.

       Z[nn]  Sleep  for nn seconds; if	nn is not present, sleeps for one sec-

       /nn    This must	be the last command on a line. It repeats the  preced-
	      ing line nn times.

       On  platforms  with  no sleep(3)	function, the Z	command	works by busy-

       Commands	are always input using fgets(3), even  when  the  host	system
       provides	a more sophisticated input method such as readline(3).

       While the current feature set is	a fairly good match for	DU90 (less the
       features	specific to the	CP/M filesystem) it doesn't cover all the fea-
       tures of	LibDsk.

       John Elliott <>.

Version	1.2.1			23 January 2008			    dskutil(1)


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