dskutil(1) Emulators dskutil(1)NAMEdskutil - Simple sector edtor for discs and disc images.
SYNOPSISdskutil [-type TYPE] [-side SIDE] [-comp COMP] [-dstep] [-retry COUNT]
[-format FMT] DISKIMAGE
DESCRIPTIONdskutil is an interactive command-driven sector editor, patterned after
the venerable CP/M sector editor DU90. This explains some of its
idiosyncracies, such as the fact that commands deal in logical track
numbers but physical sector numbers.
OPTIONS-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
default.
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.)
apridisk
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
default.
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
scanned.
-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.
COMMANDS
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.
$[variable[=value]]
View and amend the geometry. "$" 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
angle 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
buffer.
? Display a command summary.
A[from,to]
Dump the contents of the sector buffer as ASCII. If from and to
are included, then only values between those offsets will be
shown.
CHoffset,value,value,value...
Change bytes in the current sector buffer. The offset and values
are in hex.
CAoffset,ascii
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.
CHfrom-to,value,value,value...
The same as CH above, but fills the range from from to to with
the byte sequence, repeating or truncating it as necessary.
CAfrom-to,ascii
The same as CHfrom-to, except that the byte sequence is speci‐
fied as ASCII.
D[from,to]
Dump the contents of the sector buffer as ASCII and hex.
Gxx Go to logical sector number xx
H[from,to]
Dump the contents of the sector buffer as hex.
Kfilename
Save all "yanked" sectors (see Y below) to the specified file.
This also clears them from memory.
Lfilename[,type[,compression]]
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.
N[geometry]
Change geometry. N by itself re-runs the automatic probe; N with
the name of a geometry selects one of the formats known to
LibDsk.
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‐
ond.
/nn This must be the last command on a line. It repeats the preced‐
ing line nn times.
BUGS
On platforms with no sleep(3) function, the Z command works by busy-
waiting.
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.
AUTHOR
John Elliott <jce@seasip.demon.co.uk>.
Version 1.2.1 23 January 2008 dskutil(1)
