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From: bluneski@pogo.WV.TEK.COM (Bob Luneski)
Newsgroups: comp.sys.atari.st
Subject: Re: Hard Drive Problems
Message-ID: <8686@pogo.WV.TEK.COM>
Date: 13 Mar 90 00:12:01 GMT
Reply-To: bluneski@pogo.WV.TEK.COM (Bob Luneski)
Organization: Tektronix, Inc., Wilsonville,  OR.
Lines: 30

In <1814@loria.crin.fr> domen@cartan.crin.fr (Eric Domenjoud) writes:

>My questions are then:

>1) Did anybody already experience this problem?

    Yes, first when using TurboDos from Atari France along with Universal
Item Selector II and then just when using Universal Item Selector II. I have 
had no problems since I stopped using Universal Item Selector II.

>2) Are the data clusters 0 and 1 marked as free ($0000) on the ATARI disks?

    Clusters 0 and 1 are either marked as 0x0000 or 0xFFF7 depending on your
controller and are not available for data. They are not used because they 
don't really exist on the disk. Their presence is a holdover from the orignal
development of the FAT system on DOS machines.

>3) Is it posible that a poorly behaved program allocates these two non 
   existing data clusters, thinking that they are free?

Not unless they bypass the OS and program the HDC and DMA to read and write
physical sectors. If they do this and screw it up, then you can have problems.

____________________________________________________________________________
  Bob Luneski                                                             
  Diamond Back Support Hotline:  bluneski@pogo.WV.TEK.COM                
                                 Genie: B.LUNESKI1                       
                                                                         
  The opinions expressed herein are my own and in no way reflect the     
  opinions of Tektronix, Inc.