Reconciliation hard disk logic lock
Jiang Zhuo Rui
First, preamble
Due to the need for teaching, I will decide after seeing the article "Research and Application of Hard Disk Locker Technology and Application" and the 99th No. 3 "An Effective Method for Unlocking the Logic Log". Attempt, the result is not successful, and "bitter" no KV300 L version, you have to do a hard disk logic lock. During the production process, it was found that only the loop chain list was not enough, and the hard disk was not locked. The following is a method of chain and unlocking a set of locks out after multiple experiments, (herein, this article is passed!) For your reference. For the principle of the hard disk logic lock, please refer to the article above.
Second, the preparation before the production:
First, the hard drive (the author is used by the QUANTUM SE 3.2G hard disk, the C disk 2.1G, the content of the 0 head 0 cylinder 1 sector) backup into the floppy disk, which is saved here. In the floppy disk 0 head 0 cylindrical 2 sector, it is recovered when it is not successful.
C: / dos> Debug
-a 100
MOV AX, 201
MOV BX, 200
MOV CX, 1
MOV DX, 80
INT 13; reading hard disk 0 magnetic head 0 Cylinder 1 sector content to ES: 200
MOV AX, 301
MOV BX, 200
MOV CX, 2
MOV DX, 0
INT 13; write ES: 200 content to floppy disk 0 head 0 Cylinder 2 sector
INT 3
Bamboo
-g = 100
; Then make a "boot disk 1":
-a 200
MOV AX, 201
MOV BX, 2000
MOV CX, 2
MOV DX, 0
INT 13; Read floppy disk 0 magnetic head 0 Cylinder 2 sector content to ES: 2000
JB 200
MOV AX, 301
MOV BX, 2000
MOV CX, 1
MOV DX, 80
INT 13
JMP fff: 0000
Bamboo
-w 200 0 0 1; Insert the above floppy disk before performing this command, write this segment to the program that boots to the floppy disk 0 cylinder 1 sector, making it a special "starting disk 1".
Third, make a hard disk lock
Let's take a look at the information of the hard disk partition table (hereinafter, the reader is in operation, the displayed segment address is not necessarily 1186):
C: / dos> Debug
-a100
1186: 0100 MOV AX, 201
1186: 0103 MOV BX, 200
1186: 0106 MOV CX, 1
1186: 0109 MOV DX, 80
1186: 010C INT 13
1186: 010e INT 3
1186: 010f
-g = 100
-D 3B0 L 50
1186: 03B0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 80 01
Start head number
Start column (01 high 2 digits and 00)
1186: 03C0 01 00 06 7F BF 07 3F 00-00 00 C1 FB 3F 00 00 00
End the magnetic head number, sector number, and column (before the format)
Start fan code (6 digits of 01)
1186: 03D0 81 08 05 7F FF 0C 00 FC-3F 00 80 1D 20 00 00 00 00 00 00 00 00
1186: 03E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1186: 03F0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 55 AA
-e 3c2
02; change the partition type 06 to 02, ie Xenix, the height of this byte is as follows: 0- Invalid partition
1-DOS 12-bit FAT
2-Xenix
4-DOS 16-bit FAT partition capacity <32M
5-extended DOS partition
6-DOS 16-bit FAT partition capacity> 32M
-E3D0
01 00; change the starting fan area number of the D zone to the same start sector code and the column number as the C region to form a cyclic chain table
-a 100
1186: 0100 MOV AX, 301
1186: 0103 ↙
-g = 100
; Write the refunded content to the hard disk main guide sector
-a 100
1186: 0100 MOV AX, 201
1186: 0103 ↙
-g = 100
; Read out the hard disk main guide sector content
-D 3B0 L 50
1186: 03B0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 80 01
1186: 03C0 01 00 02 7F BF 07 3F 00-00 00 C1 FB 3F 00 00 00
1186: 03D0 01 00 05 7F FF 0C 00 FC-3F 00 80 1D 20 00 00 00 00 00 00 00 00 00 00
1186: 03E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
1186: 03F0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 55 AA
The display indicates that the above partition table has been changed.
-Q
Exit Debug, restart the system, everything is OK! Haha, floppy disk, hard disk can not start the system!
Fourth, symptom description:
1. Only modify the partition type of the C disk, so that the partition type 06 is changed to 02, the hard disk cannot be started, and the A disk can be started.
2. Only the loop chain list, WIN95 / 98 can not start, but the DOS 6.22 can start normally. After startup, there will be the same capacity, 24 logical drives of the same data (from the C drive to Z disk), prompting the following error message:
WARNING: Logical Drives Past Z EXIST AND WILL BE IGNORED
The author has been a circulating partitioned linked list for many years, it can be said to the startup of DOS 6.22, but the fdisk command to DOS 6.22 is very useful. When the run is "dead" (same as WIN95 / 98, due to cyclic check partition linked list It is dead.).
3. After two of the above two, the C disk, the DOS 6.22 of the A disk cannot be started, but the DOS 3.3 of the A disk can be used to start. After startup, you can run the fdisk command, you can also modify the partition table with tool and other tools (no need to take care of the C disk capacity More than 33M).
It can be seen that the hard disk logic lock is only valid for DOS high versions, and the DOS 3.3 does not work, and the loop chain table is valid for WIN95 / 98.
V. Unlock the hard disk lock:
The method of modifying CMOS in the "Research and Application of Hard Disk Logic Lock Technology" is also unable to start the system, and it is impossible to unlock this logic lock. You need to make a "startup on another machine" Disc 2 ", the specific process is as follows:
C: / dos> Debug
-a 100
MOV AX, 201
MOV BX, 2000
MOV CX, 1
MOV DX, 80
INT 13
MOV Al, 06; C is changed to 06
MOV [21C2], Al
MOV Al, 0
MOV [21D2], Al; D is changed to 0, shield other partitions
MOV [21E2], Al; E partition type change to 0 purposes to destroy the circulation chain
MOV [21f2], Al; F partition type change to 0
MOV AX, 301
MOV BX, 2000
MOV CX, 1
MOV DX, 80
INT 13
JMP fff: 0000
Bamboo
-w 100 0 0 1; write this segment to the logical 0 sector of the floppy disk, so that it is a boot program
-Q
Used as a good "start disk 2" to start the deadlock machine, then remove the "boot disk 2", turn it over again to the DOS 6.22 system again, at this time, use the Norton's Diskedit.exe and other tools or use Debug to repair partition tables .
If you press the original main guide back up to the second fan of the floppy disk, you can also use the "Start Disk 1" to restore the contents of the main boot sector.
Address: 430062 Hubei University School of Economics, Lei Bun
E-mail: laybw@163.net
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