23 Apr
2005
23 Apr
'05
7:11 p.m.
I'm currently using Anadisk to dump disks into image files. The problem
is, Anadisk, like 22disk, is retarded. If it hits an error it skips the
sector but does not put a blank sector in the image file. You have the
option of placing a sector header before each sector, but for manipulating
disk images, this is a piss poor way to mark missing sectors. Anadisk
also has the annoying habit of ignoring the start and finish cylinders and
merrily proceeds to read the entire disk, relegating the need to ask you
what cylinders you want dumped superfluous.
Is there anything in Linux that will dump a disk image and put blank space
where bad sectors are? It's not certain if dd does this.
I'm sick of the crap programming of others. Must I write *EVERYTHING*
myself?
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
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23 Apr
23 Apr
8:05 p.m.
On 4/24/05, Vintage Computer Festival <vcf at siconic.com> wrote:
I'm currently using Anadisk to dump disks into image files. The problem
is, Anadisk, like 22disk, is retarded. If it hits an error it skips the
sector but does not put a blank sector in the image file. You have the
option of placing a sector header before each sector, but for manipulating
disk images, this is a piss poor way to mark missing sectors. Anadisk
also has the annoying habit of ignoring the start and finish cylinders and
merrily proceeds to read the entire disk, relegating the need to ask you
what cylinders you want dumped superfluous.
Is there anything in Linux that will dump a disk image and put blank space
where bad sectors are? It's not certain if dd does this.
I'm sick of the crap programming of others. Must I write *EVERYTHING*
myself?
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
Can't really help you much, I've never tried to copy a disk with
errors before. But I've used these before, they mostly run on msdos or
linux. It also depends on what disks you're trying to copy.
fdcopy
teledisk
copyqm
apridisk
libdsk
Dan
8:33 p.m.
I'm sick of the crap programming of others. Must
I write *EVERYTHING*
myself?
I cna;t help with your problem, but if it's any consolation, that's how I
often feel about hardware. It appears that to get anything that I
consider to be even moderately well-designed, I have to design it myself
these days...
-tony
24 Apr
24 Apr
10:23 a.m.
On Sat, 23 Apr 2005 16:11:11 -0700 (PDT)
Vintage Computer Festival <vcf at siconic.com> wrote:
I'm currently using Anadisk to dump disks into image files. The
problem is, Anadisk, like 22disk, is retarded. If it hits an error it
skips the sector but does not put a blank sector in the image file.
You have the option of placing a sector header before each sector, but
for manipulating disk images, this is a piss poor way to mark missing
sectors. Anadisk also has the annoying habit of ignoring the start
and finish cylinders and merrily proceeds to read the entire disk,
relegating the need to ask you what cylinders you want dumped
superfluous.
Is there anything in Linux that will dump a disk image and put blank
space where bad sectors are? It's not certain if dd does this.
I'm sick of the crap programming of others. Must I write *EVERYTHING*
myself?
Well, the cool thing about the free Unices (and Linux) is that you can
dig into the source code for dd and find out. And if it doesn't put
blank space where errors occur, you can modify it to do so. Perhaps
with a command-line switch option, if one doesn't already exist.
I'm sick of the crap programming of others. Must
I write *EVERYTHING*
myself?
Naw, just the bit that will scratch your particular itch. And if you
make changes to dd and submit your changes back, nobody else will have
to rewrite it either.
2:19 p.m.
Well, the cool thing about the free Unices (and Linux)
is that you
can dig into the source code for dd and find out. And if it doesn't
put blank space where errors occur, you can modify it to do so.
Perhaps with a command-line switch option, if one doesn't already
exist.
dd conv=noerror,sync
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25 Apr
25 Apr
12:54 p.m.
Scott Stevens wrote:
On Sat, 23 Apr 2005 16:11:11 -0700 (PDT)
Vintage Computer Festival <vcf at siconic.com> wrote:
Another one to look at is dmklib
http://dmklib.brouhaha.com/
That one worked for me to read several Kaypro disks under Linux.
I think it works the way you expect for bad sectors.
I'm currently using Anadisk to dump disks into
image files. The
problem is, Anadisk, like 22disk, is retarded. If it hits an error it
skips the sector but does not put a blank sector in the image file.
You have the option of placing a sector header before each sector, but
for manipulating disk images, this is a piss poor way to mark missing
sectors. Anadisk also has the annoying habit of ignoring the start
and finish cylinders and merrily proceeds to read the entire disk,
relegating the need to ask you what cylinders you want dumped
superfluous.
Is there anything in Linux that will dump a disk image and put blank
space where bad sectors are? It's not certain if dd does this.
I'm sick of the crap programming of others. Must I write *EVERYTHING*
myself?
Well, the cool thing about the free Unices (and Linux) is that you can
dig into the source code for dd and find out. And if it doesn't put
blank space where errors occur, you can modify it to do so. Perhaps
with a command-line switch option, if one doesn't already exist.
I'm sick of the crap programming of others.
Must I write *EVERYTHING*
myself?
Naw, just the bit that will scratch your particular itch. And if you
make changes to dd and submit your changes back, nobody else will have
to rewrite it either.
6:35 p.m.
Kevin wrote:
Another one to look at is dmklib
http://dmklib.brouhaha.com/
That one worked for me to read several Kaypro disks under Linux.
I think it works the way you expect for bad sectors.
If it gets read errors, it will omit those sectors from the DMK
format output file. In other words, there will be a "hole" where
that sector should have been.
I don't recall what behavior you get if you ask the rfloppy program
to write a "raw" image, or run the DMK image through dmk2raw. If I
was thinking straight when I wrote it, I think the correct behavior
would have been to put zeros in the raw image and write a warning
message to stderr, but I might not have taken the time to code that.
Glad to hear that it's been useful to someone! I wrote it when I
needed to read some TRS-80 Color Computer OS-9 disks, and some
Xerox 6085 disks, and various DEC RX01 8-inch disks. Unfortunately
PC disk controllers are not capable of reading DEC RX02 double-density
8-inch disks, as DEC used a non-standard encoding (a modified form
of MFM, though not M2FM, but with FM ID fields).
Eric
24 Apr
24 Apr
2:30 p.m.
On Sat, 2005-04-23 at 16:11 -0700, Vintage Computer Festival wrote:
Is there anything in Linux that will dump a disk image
and put blank space
where bad sectors are? It's not certain if dd does this.
I believe you want the 'noerror' (obviously) and 'sync' options to dd,
and it'll pad the data with zeros as necessary. (best way might be to
find a known-bad disk and see if you get the right image size out of
it!)
cheers
Jules
25 Apr
25 Apr
9:44 a.m.
>>>> "Vintage" == Vintage
Computer Festival <vcf at siconic.com> writes:
Vintage> Is there anything in Linux that will dump a disk image and
Vintage> put blank space where bad sectors are? It's not certain if
Vintage> dd does this.
Neither Linux the manpage nor the info for dd is clear on this. But
the NetBSD manpage says that if you say "conv=error" then dd will omit
any bad blocks from the output, while if you say "conv=error,sync" it
will substitute zeroes for bad blocks.
You may have to use blocksize=512 for this to work best, otherwise dd
may null out whole buffers full if any one block in the I/O is bad. I
haven't checked that, though.
paul
10:24 a.m.
On Mon, 2005-04-25 at 09:44 -0400, Paul Koning wrote:
That's interesting. I've not seen a mention of an 'error' param before
in the *linux* dd man pages, and don't recall it from other platforms
that support dd either. There's a *noerror* param though - if set then
it allows dd to continue even if it hits a read (and presumably write)
error. If not set then dd will bail at the first sign of trouble.
One thing that'd be useful would be a patched version of dd that could
also retry reading bad blocks n times up to some command-line supplied
maximum; quite often I find for marginal data (such as flakey floppies
and hard disks) an initial read might work but one or more subsequent
reads work find. Far as I know standard dd won't retry reading data at
all.
I've hacked together scripts before to do this, but a patch to the
actual dd code would be a lot more elegant.
cheers
Jules
>>>> "Vintage" == Vintage Computer Festival <vcf at
siconic.com> writes:
Vintage> Is there anything in Linux that will dump a disk image and
Vintage> put blank space where bad sectors are? It's not certain if
Vintage> dd does this.
Neither Linux the manpage nor the info for dd is clear on this. But
the NetBSD manpage says that if you say "conv=error" then dd will omit
any bad blocks from the output, while if you say "conv=error,sync" it
will substitute zeroes for bad blocks.
10:55 a.m.
>>>> "Jules" == Jules Richardson
<julesrichardsonuk at yahoo.co.uk> writes:
Jules> On Mon, 2005-04-25 at 09:44 -0400, Paul Koning wrote:
> >>>>> "Vintage" ==
Vintage Computer Festival <vcf at siconic.com>
> writes:
>
Vintage> Is there anything in Linux that will dump a disk image and
Vintage> put blank space where bad sectors are? It's not certain if
Vintage> dd does this.
> Neither Linux the manpage nor the info for dd is
clear on this.
> But the NetBSD manpage says that if you say "conv=error" then dd
> will omit any bad blocks from the output, while if you say
> "conv=error,sync" it will substitute zeroes for bad blocks.
Jules> That's interesting. I've not seen a mention of an 'error'
Jules> param before in the *linux* dd man pages, and don't recall it
Jules> from other platforms that support dd either. There's a
Jules> *noerror* param though - if set then it allows dd to continue
Jules> even if it hits a read (and presumably write) error....
Sorry, slip of the finger. "noerror" is what I meant to say. So
"conv=noerror,sync" should do the job.
paul
4:56 p.m.
New subject: Need good disk dump utility (dd is one)
freebsd 5.3
$ man dd
...
conv=value[,value ...]
Where value is one of the symbols from the following list.
...
noerror Do not stop processing on an input error. When an
input error occurs, a diagnostic message followed by
the current input and output block counts will be writ-
ten to the standard error output in the same format as
the standard completion message. If the sync conver-
sion is also specified, any missing input data will be
replaced with NUL bytes (or with spaces if a block ori-
ented conversion value was specified) and processed as
a normal input buffer. If the fillchar option is spec-
ified, the fill char provided on the command line will
override the automatic selection of fill character. If
the sync conversion is not specified, the input block
is omitted from the output. On input files which are
not tapes or pipes, the file offset will be positioned
past the block in which the error occurred using
lseek(2).
...
sync Pad every input block to the input buffer size. Spaces
are used for pad bytes if a block oriented conversion
value is specified, otherwise NUL bytes are used.
6:34 p.m.
Not mentioned so far is dd_rescue,
http://www.garloff.de/kurt/linux/ddrescue/
It copies in large chunks until an error is seen, then backs off to
smaller reads, attempting to get what it can. You can restart a copy
from a new point, which extends the current dump file
to skip the area
that hasn't been (or couldn't be) read. You can also read
in reverse,
backing up from the end of the media to the point of an error.
There's a gnu program that does the same things, ddrescue
http://www.gnu.org/software/ddrescue/ddrescue.html. It seems to be
slightly more automatic, but similar in operation to dd_rescue.
-Rick
26 Apr
26 Apr
3:41 p.m.
Vintage Computer Festival wrote:
Is there anything in Linux that will dump a disk image
and put blank space
where bad sectors are? It's not certain if dd does this.
I wrote disk2img that you can get from the www.oldskool.org/pc/flopper package;
source included. When it encounters a sector it can't read, it fills it with
"!" in the image file.
Without specialized hardware, your best bet for imaging disks (for the purpose
of recreating them in the future) is probably copyiipc used with "snatchit".
Snatchit was a pirating tool in the mid 1980s that interfaced with copyiipc and
dumped its memory buffers to disk, and could read them back to recreate the
disks. The format is proprietary and the software only runs on pre-1990 x86
hardware, but if you want to image diskettes, even bad/wacky/protected formats,
it's the easiest way to go.
It's much more competent than anadisk, but the proprietary nature of the
process is probably a huge turn-off. If you need both programs, let me know
off-list and I can make them available.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
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13 comments
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participants (12)
-
ard＠p850ug1.demon.co.uk -
chenmel＠earthlink.net -
eric＠brouhaha.com -
julesrichardsonuk＠yahoo.co.uk -
kth＠srv.net -
mouse＠Rodents.Montreal.QC.CA -
pkoning＠equallogic.com -
rick＠rickmurphy.net -
tomj＠wps.com -
trixter＠oldskool.org -
vcf＠siconic.com -
williams.dan＠gmail.com