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中国DOS联盟论坛 » DOS疑难解答 & 问题讨论 (解答室) » Experts in data recovery, please come in!!! View 1,035 Replies 2
Original Poster Posted 2003-05-04 00:00 ·  中国 江苏 苏州 电信
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I used WINHEX (a piece of software for viewing disk data in hexadecimal under WUNDOWS) to look at the information on drive C: (primary partition, file

system is FAT32). I discovered that the FAT area does not appear until the 33rd sector after the system boot record sector. I remembered that it should come immediately

after the system boot record sector. Later I converted the code in bytes 15 to 16 of the BPB in the system boot record

into decimal, and it came out to exactly 33 (could these two bytes be used to indicate the starting sector of the FAT? I remember that in a FAT12 system

they indicate reserved sectors, and generally are 1). Also, in sector 6 there is actually information completely identical to the system boot record, which

I really don't understand?。。。。。。。。。
Floor 2 Posted 2003-05-04 00:00 ·  中国 江苏 苏州 电信
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Also, if recovering files manually (using only DEBUG), how can I find that file's directory entry table? In the directory table only its filename is in ASSIC code; does that mean I also need some software to look up that filename? Also, under what circumstances will the first byte of the filename in the directory table of a deleted file not be changed to E5? In that case, how should recovery be done? 。。。。If recovering directly from sectors in the data area, then how should it be done?     
  Can you tell me specifically how to do manual recovery? 。。。。Thanks!!!
            
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Floor 3 Posted 2003-05-04 00:00 ·  中国 北京 263网络通信股份有限公司
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Inside the boot record,
byte 14 is Reserved sectors 32(32 reserved sectors)
byte 16 is Number of FATs 2 (2 FATs)
So just as you said, because 32 sectors are reserved, the starting position of the FAT is sector 33
Among the 32 reserved sectors, sector 6-8 are backups of sector 0-2. I once used this backup before to restore the boot sector

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