Restoring a saved document.

[alexcraw]

Hi

We have a problem here in our school where one of our upper school students has been working on a drawing in Techsoft 2d Design. She had a piece of work saved from an earlier time and opened it to do more work on it. She was working on another drawing simultaneously and accidentally saved the main drawing incorrectly. Is there a way to revert the recently saved drawing back to it's previous state?

The PC is:

500Mhz
128Mb RAM
Win98SE

Software:

Techsoft 2d Design (filetype = *.dtd)

[Sylvander]

I know nothing of that program, but can it [and was it][like MS Word] be configured to make automatic backups?
Also, when working in Word, if the PC crashes, a copy of the document being worked on is saved in a Temp folder. [something like "recovered.doc" would be searched for made on that day] Might anything like that have happened recently and a ".dtd" file saved?

Are any backups ever made [manually or otherwise]?

I wonder if you could "unerase" an older copy of the file.

There's an "un-erase" program on the EBCD bootable "Emergency Boot CD".
I'll go try that out.
How to make an EBCD bootable CD
http://www.pcguide.com/vb/showthread.php?t=41485

[Sylvander]

Booted from the EBCD and ran the "un-Erase" program.

It looks pretty good.
You choose the drive to examine, and navigate to a folder, and it lists all the files that were in that folder and are now deleted, and you can "un-erase" any number of chosen files.
It lists the probability of a successful unerase beside each file.

You should, of course, first look in the Recycle Bin for deleted copies of your file. If the file was deleted from the bin, then use the "Un-Erase" program to try to recover it.

[alexcraw]

I take it the computers method of "saving" involves deleting the file which was opened and then saving the up to date version? Kind of like throwing the whole document out and then accepting an entirely different one in it's place.

If that's the case then you are saying that the previous "saves" will be in the folder found by the "un-erase" tool on the EBCD.

Have I got the gist of this?

[Sylvander]

"I take it the computers method of "saving" involves deleting the file which was opened and then saving the up to date version? Kind of like throwing the whole document out and then accepting an entirely different one in it's place."
That is my assumption; that the old copy of the file as it was when opened is deleted, and the new copy saved in its place. Rather like an automatic "Save As" with the old copy deleted.

"If that's the case then you are saying that the previous "saves" will be in the folder found by the "un-erase" tool on the EBCD."
That's exactly my theory. It will be interesting to see if its correct. Perhaps I should test the theory out myself. I'll get back to you when I've tried it out.

"Have I got the gist of this?"
You have indeed. :)

[Sylvander]

Unfortunately my theory was only partially correct.

1. I copied a blank document into my C:\00tmp folder | typed some text into it and saved it | altered the text and saved that.

2. Used the EBCD "Un-Erase" program to find the file [it was there ok, the only such file in that folder I had EVER updated] and un-erased/recovered it.

3. When I got back into Windows, sure enough the recovered [old] file was there alongside the updated [new] file, but the only info in it was gibberish.
Perhaps I didn't do it correctly?
I must study how this should be done.

[Sylvander]

I know very little about the business of "unerasing" [I prefer to think of it as "un-deleting"] files and that is showing. :(

I can find the "deleted" file using "un-erase" [I had never actually deleted it] and the contents that I can read must be from some time previous because they didn't showed in that doc file when I first opened it within C:\00tmp.
I have a saved doc file on the desktop and work in that and then delete the contents, so the file looks empty.
I then copied that empty doc file to C:\00tmp, added the text, saved it, added some more text, saved it.
Yet when I examined the doc file of that name deleted in C:\00tmp it didn't have that text inside it, but some other text that must have been deleted earlier.
Beats me! :( :confused:

And when I recovered it none of any of it showed. :confused:

[Paul Komski]

and accidentally saved the main drawing incorrectly
Please elaborate as much as possible.

If the file still exists (even as a deleted file) then see if you can dig it out with GetDataBack for FAT from www.runtime.org. It should be safe enough to run it from the actual partition since the drive itself is not corrupted.

[alexcraw]

This will be a time consuming job, so I'll give creating the disc a go over the weekend and try it out on Monday.

Thanks for all the help so far, I'll keep you up to date with our progress.

Cheers

Alex

[Sylvander]

I wish I knew more about what happens in the background when a file is updated, because this all relies upon "something" of the original file arrangement remaining if only as a "deleted" copy.
Somewhere the original arrangements of 1's & o's may still exist on the HDD, unless they get overwritten by the changes.

[Paul Komski]

I wish I knew more about what happens in the background when a file is updated
On FAT partitions, at the most basic, the data for an updated file stays where it is as long as no new clusters need to be utilised; in other words the FAT tables are not changed at all even though the ones and zeros will have been changed in the data area that they reference.

Changing the file name or other attributes creates a new entry in the appropriate directory area but doesnt need to rewrite the data area either. If the file becomes contracted or expanded such that the FAT tables need editing then the OS makes a decision whether to just extend/contract the existing "daisy-chain" or write a complete new area with the relevant data. This would be done whenever possible if it would prevent the file from becoming fragmented. If the data gets written in a new location the original file data stays where it is until it gets overwritten. In such circumstances the original may well be recoverable by good software - but it is by no means a given.

The best way of oberving these events is to create a small partition, write zeros to it and then format it as FAT. Then create one small file on it. Then make minor alterations to it; etc, etc. Examine each stage with a Hex editor and everything begins to fall into place.

[Sylvander]

"If the data gets written in a new location the original file data stays where it is until it gets overwritten. In such circumstances the original may well be recoverable by good software"
I was hoping something like that might be the case; here's hoping alexcraw gets lucky. :)