A bridge between computer hardware and software programs 9

We know that there are two types of BIOS passwords: User Password and system password. The former is used only when BIOS is set, and the latter is required before self-check. The following describes how to clear the user password. Because the system password is cleared, only two methods are available now .. first, of course, it is discharged. Second, it is to find the default password of the manufacturer .... (I will also mention it below ).

1. The most common and simplest method-Debug Method
In general, the computer's CMOS settings can be accessed and changed through the 70h and 71h ports. The simplest way is to clear all the ports, that is, to change them to the default settings. The followingProgramSegment is to use the DEBUG command to clear the CMOS Data, debug is an external DOS command, you can find it in the Windows \ command directory, start the computer to the MS-DOS environment, enter debug in the DOS symbol and press Enter. # The process is as follows:
C: \ dos> debug
-O 70 21
-O 71 20
-Q

Or:

C: \ dos> debug
-O 70 10
-O 70 01
-Q
Note: "-" is generated by the system itself, so you do not need to enter it.
Then restart and you will find that the user password has been cleared .. (I will use this method to overclock the piii800 machine in the school, and add 0.5v....results ...... the teacher is at a loss ....)

2. the most straightforward method -- Discharge Method (...... the most BC is also the most practical method ...)
In this method, you need to open the chassis, locate the CMOS battery, and discharge the battery. In fact, most of the current mainboards are configured with jumpers or DIP switches for CMOS battery discharge. Generally, find the jumper or switch, and switch for several seconds or switch for several seconds. If your motherboard is an old motherboard, there is no CMOS battery discharge jumper or dip switch, or you cannot find the motherboard manual, you do not know which group is a CMOS battery discharge jumper, then you simply unplug the CMOS battery and connect the exposed pins to one sub-device (in fact, it will take a few seconds, however, some articles say it takes 1 hour .... khan ..... that is, let CMOS automatically clear the content without power supply for a long time.

3. software Implementation ....... (This is found online ......)
using software (such as pctools and Norton), you can easily clear the CMOS password. Here are two simple examples:
1. bootsafe (bootsafe. EXE can be found in pctools 9.0)
RUN bootsafe C:/m to back up the CMOS information and boot zone information to a blank floppy disk to form a CMOS. CPS and cboot. CPS two text files, and then use an editor such as Edit to put CMOS. CPS arbitrarily modifies some content. After saving the disk, use the disk to start and run bootsafe C:/R. The system will ask whether to recover CMOS Data from the floppy disk (answer yes) and whether to recover partition table data from a floppy disk (answer no), and then restart. At this time, all the content in CMOS has been cleared.
2. rescue (rescue can be found in Norton 8.0)
use the rescue function of Norton to create an emergency disk, and use an editor such as Edit to modify the CMOS of the emergency disk. the content of the DAT file. After saving the disk, start it with an emergency disk. Run rescue. EXE in the emergency drive, and select "CMOS infomation" in item to restore. After the operation, restart the system.
3. biospwds (available for download from major software sites)
biopwds allows you to easily learn the BIOS password. It is also quite simple to use. After running this tool, there will be a biospwds tool user interface, just press "get passwords" on the interface 」, the BIOS information will be displayed on the biospwds interface in two or three seconds, including the BIOS version, BIOS date, and password. Then you can easily learn the BIOS password.
... Of course, you can access the system, use other tools (many and many), and check the password. Here we will not talk about this...

4. Cracking Method... In fact, it should be put in the above software method... forget it... comparison... impractical... write it separately...
Here is a basic program.Code... Bored when I was studying .....
Color 10, 5
Dim A (9)
CLS
Print space $ (980); tab (22); "the password for zhe BIOS is :";
Out & H70, 28
P = Indium (& h71)
Out & H70, 29
Q = Indium (& h71)
X = 16 ^ 2 * q + P
Color 30,5
I = 0: J = 0: n = 0
Y = x + I ** 65535
Z = int (3 * Y/(4 ^ (n + 1)-1 ))
If z <= 126 then 190
N = n + 1
If n <8 then 140
I = I + 1: J = 0: n = 0 = 16 ^ 2 * q + P: goto 130
If z <32 then 180
A (j) = z: J = J + 1: A = Y-Z * 4 ^ n
If a = 0 then 230
N = N-1: Y = A: goto 140
For k = 0 to J
Print CHR $ (A (k ));
Next
Color 10, 5
End
* ******* You can understand the principle ..... back a table like me .... (actually, it's useless .... like BC ....)

I forgot to mention the number of things... I found several methods for BT ....

5. ASCII Method

If you do not want to download the software, do not want to open the chassis, or do not want to change the hardware configuration, the following methods are believed to help you crack and recover the BIOS password:
1. Go to the MS-DOS environment, enter edit under the DOS prompt and press ENTER(If you find that an error occurs when you press edit, that is, you do not have the edit.com file, please refer to the next method), enter:
Alt + 179 Alt + 55 Alt + 136
Alt + 216 Alt + 230
Alt + 112 Alt + 176 Alt + 32
Alt + 230 Alt + 113
Alt + 254 Alt + 195 Alt + 128
Alt + 251 Alt + 64
Alt + 117 Alt + 241 Alt + 195
Note: If you enter the preceding data, press the Alt key, and then press the numeric key in the numeric keyboard (the row above the keyboard does not work, after entering a number, release the Alt key and press the Alt key. In the # process, there will be a messy character on the screen, so we don't need to worry about it. Then select save in the file directory, save as cmos.com, and then exit to the MS-DOS environment, press find cmos.com this file, to see if it is 20 bytes, if not, it means you hit the wrong, enter again. After confirmation, run cmos.com to clear all CMOs data (including passwords ).
2. This method can be completed directly in the MS-DOS EnvironmentIn the MS-DOS environment, enter:
Copy con CMOS. com
Press enter to continue entering:
Alt + 176 Alt + 17 alt + 230 P Alt + 176 Alt + 20 Alt + 230 Q Alt + 205 <space>
Then press "F6", Press enter to save, run the cmos.com file, and restart the system.

6. Change the hardware configuration

When the microcomputer starts, the BIOS program first needs to check whether the hardware configuration of the computer is consistent with the parameters set in CMOS. When there is a conflict or inconsistency, it will automatically enter the setup program after the boot, without entering the password. With this principle, we can open the chassis and change a hardware configuration to automatically clear the password. The procedure is as follows:
(1) Open the chassis and change the original configuration of the machine, for example, disconnect the sound card or the data cable of the soft drive.
(2) restart the computer. After the machine automatically enters the setup program, you can reset the CMOS password.
(3) After the CMOS password is reset, press F10 to save the settings and restart the machine for the settings to take effect.