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From: ia4@cunixd.cc.columbia.edu (Imran Anwar)
Newsgroups: comp.sys.atari.st,comp.sys.ibm.pc
Subject: IBM PC / ATARI ST Disk Screwed Up
Message-ID: <2646@cunixc.cc.columbia.edu>
Date: 18 Jan 90 21:58:49 GMT
Sender: news@cunixc.cc.columbia.edu
Reply-To: ia4@cunixd.cc.columbia.edu (Imran Anwar)
Distribution: usa
Organization: Columbia University
Lines: 49

Here is a simple problem :-)

I use an Atari 1040 ST on which I can prepare and save text files on PC format
720K 3.5" disks. These I take to school and use them in the NCR PCs there for 
printouts as I have no printer :-(

Recently the school added some HP PCs with 1.4M 3.5" floppies. There seems to 
be a compatibility problem as the 1.44M drives do not read 720K floppies made
on the NCR PC compatibles (or my Atari ST).

One of the staff there solved the problem by "Formatting a Low Density 3.5" 
Disk on a High Density Drive" command available in the menu. Sure enough,
the floppy formatted as 720K on the 1.4M machine worked fine on the 720K drives
including my Atari ST drive.

So I spent the whole night typing some reports and saved them on this floppy. 
The next day, at school, I had to use the 1.4M drive PC as that is the one 
connected to a Laserprinter. But, surprise, that very drive that had formatted
the disk showed it to be blank (even though the files showed up on the 720K 
drive PCs). It simply said, File Not Found.

What could be the problem?

But wait. That is not all :-(  . I then typed a small note on the PC and when
I tried saving it on my disk I got a Disk Error 27. Checking the disk on a 
720K drive showed that the directory had been corrupted. Some of the files I
had created just did not exist anymore :-{. Also the bytes remaining number
showed up as ^&%#$&($&*$&) or something. And a few files with similar garbage
names showed up. But when I tried to delete or open them they were "not found".

I took the disk home and used a disk doctor type program to read the sectors.
I found that most of the matter for my files was still there on disk eg from
Sector 118-120, #140-149 etc. Also, the program has an option to recover files
accidentally deleted by making their names again visible in the directory. But
this program failed to do so. Checking the first few sectors of the disk showed
that: Names of exisitng files are saved on those sectors, names of files delete
d by me show up but with a Hex E5 replacing the first letter of the file
name, but the names of my three lost files donot show up at all. Hence the 
program cannot recover them.

My question(s). Any idea of what could have happened? Solution?

Also, is there any PC utility I can use that helps recreate files simply by
allowing sectors to be linked even if the filename is missing from directory?

Any help will be appreciated. I also wonder if other people have had this 
problem.

Imran Anwar