CPCWiki forum

General Category => Applications => Topic started by: nivrig on 00:09, 26 October 11

Title: Undelete or Recover files from a disk?
Post by: nivrig on 00:09, 26 October 11

Is there a CPC or Windows based utility that can search a (potentially partially corrupted) DATA format disk and recover or undelete files on it?

Title: Re: Undelete or Recover files from a disk?
Post by: SyX on 18:07, 26 October 11
In the wiki appears this tool (http://www.cpcwiki.eu/index.php/Dir_Doktor), but you can find a lot of disk tools here (http://www.cpc-power.com/index.php?page=utilitaire) (search for disc, era or similar string), i don't know which tool recommend you, because the last time that i need recover files from a disk, i was using DiskSalv in my Amiga :P

Although to recover or undelete files, you can use a hex editor, load the disk image, the catalog the first 4 sectors (remember that they are interleaved 1,6,2,7,3,8,4,9,5), the byte before each filename is the USER for that file (usually a 0) an $E5 in the case is erased, change the $E5 to 0 and the file will appear when you make a CAT... of course, the sectors can be in use by other file written in the disk at a later date.
Title: Re: Undelete or Recover files from a disk?
Post by: Cholo on 19:39, 26 October 11
Well, ive never been much of a disc user myself, and im trying hard to recall the names of programs ive used for saving files from disc/tape. I remember especially a quite nifty program that allowed you to load basic programs even tho they suffered from Error A/B and then allow you to delete/alter the bad lines in the middel of the program and save it somewhere else safely.
Also there is a lot of "Disc format" or "disc edit" tools out there that allow you to un-hide, un-delete whole files or just view/edit single bytes/sectors.
Then there is the programs to use after recovering the discs to "mark" bad area on the disc with "dummyfiles" so that the rest of the disc becomes usefull again.

Here is a couple i can remember from AA tapes:

Disc Editor, Amstrad Action, issue 28, jan 1988 "Christmas 1987" (the christmas tape with The Duct on one side): Disc monitor/editor program (aka view/edit disc directly as Hex and Chars a bit like Maxam assembler view).

DMon, Amstrad Action issue 88, January 1993 Tape "Pack 22": Another Disc sector editor program.

Special Disc Formatter, Amstrad Action issue 37, oct 1988 "Birthday" (the birthday tape with the AA Dizzy SE game on one side): This program will reformat the disc and mark all bad sectors into a "corrupted"-dummy file. (Note it erases the disc so only use AFTER you have saved your data/files).
Title: Re: Undelete or Recover files from a disk?
Post by: Johnny Olsen on 00:52, 27 October 11
A quick way to see deleted files is poke &a701,&e5 then make a cat.
You can now load a file - poke &a701,0 and save it again.
This works for basic files not overwritten.
Title: Re: Undelete or Recover files from a disk?
Post by: TFM on 07:21, 27 October 11
Is there a CPC or Windows based utility that can search a (potentially partially corrupted) DATA format disk and recover or undelete files on it?

You can use the REName function of FutureOS. Just change to user number from &E5 back to &00.
 
Title: Re: Undelete or Recover files from a disk?
Post by: TomEtJerry on 21:06, 27 October 11
Hello,

If the directory of the disk is totally damaged, you can use Dir Doktor. This tool is not very "user friendly" (sorry, done for my own business when I used to store datas on an external drive that sometimes had the strange habit to unformat track 0), but is always better in most cases that other programs not designed for this difficult task.

T&J/GPA
Title: Re: Undelete or Recover files from a disk?
Post by: TFM on 21:44, 27 October 11
Well, if you have problems reading sectors, you also can reduce the number of reads to 1 under FutureOS and you get what the FDC delivers. Check it 3 times and be sure that some reads are the same. This always brought best results to me. If detailed help is needed let me know.
Title: Re: Undelete or Recover files from a disk?
Post by: Executioner on 03:26, 28 October 11
From ParaDOS, choose 'F'ilespec, then use the left cursor key to go to the User: field and enter 229. You should then be able to see the deleted files and use 'M'ove to move them back to User 0.
Title: Re: Undelete or Recover files from a disk?
Post by: AMSDOS on 05:31, 29 October 11
There was something like this in AA50:
 
Code: [Select]

poke &a701,229:|ren,"0:filename.ext","filename.ext":poke &a701,0:cat

which works in BASIC 1.1.
Title: Re: Undelete or Recover files from a disk?
Post by: 00WReX on 04:49, 31 October 11
OddJob from Pride Utilities (1985) has a utility within it called "Diredit". This has an "unerase" option.
If files are erased and available to be unerased it will list them.

Check out the screenshot...
 
Cheers,
Shane