DEBUG SCRIPTS

What is the DEBUG command?

Debug is a MS-DOS command which can be used to enter machine language into the computer either to create programs or test computer peripherals by receiving back various computer machine code. Within this page as well as other pages you will begin to understand how to utilize this great method of testing computer hardware. As well as learn the basics of machine code. Debug has been included in every version of MS-DOS as well as Windows. When running any of the debug routines it is recommended that if you have Windows that you exit or shut down to get into a real DOS prompt. To exit out of a debug type q and press enter. This will return you back to the MS-DOS prompt. In some of the following debug routines you will notice that a g is typed then q. G tells the computer that the code type is not self executing and must be ran at this point. If completed the program will return Program Terminated Normally which indicates you can quit from the debug program. If during the time you are typing the debug routine you receive ^ error this is an indication that you have incorrectly typed something within the line just completed. You can type the line again without causing any problems with the routine.

Display Information about your computer ports:

You should get several lines however the first line is the only important line. If you see F8 03 this would be an indication that COM1 is being detected if you see 00 00 this is an indication that it is not being detected, which could mean that hardware is bad or that it is disabled in CMOS. Once you have finished looking at the information type Q and press enter to get out of Debug.

Clear CMOS

The following debug routine will clear CMOS, BIOS, Passwords, Settings, Viruses, and other items residing in the CMOS. During this process you may get returned characters which are an indication that the string has gone in, if you by chance get ERROR insure that you have typed the line in correctly, if not retype. 

JOYSTICK TEST

This test will test to see if you Joystick is present or not.

ERASING SECTOR 2 ON YOUR HARD DRIVE

Before doing the below routine make sure that this is safe to do on your hard drive. This could cause damage to the hard drive, and some computer hard drive manufacturers may void your warranty.

This routine is useful in clearing DDO. If this routine completes successfully it will erase everything in Sector 2. In the following debug routine only type what is in bold from line 3 to 9 you will get a response if it corresponds with the following type the text after the response without putting in a space between the response and what you type in.

Create A Batch File That Reboots Your Computer.

CHECK BIOS DATE

The following debug routine is to check the date of your BIOS. All BIOS dates on PC compatible computers is stored at memory address FFFF5h. To display the date of your BIOS do the following:

Determine Your Video Card Type

The following debug routine will list the type of video card within your computer. This is an excellent way of determining the chipset on the card or the card within your computer without opening the computer. 

As you can pick out in the above dump this gives you enough information to determine the make and the year made on the video card. On line 4 you can see the make of this video card which in this case is a N VIDIA TNT which would be the Riva TNT chipset. The next line you notice the version of the card and finally the line thereafter is the copyright or the year manufactured generally. If you are unable to capture any information which sounds like the video card you can also type:

 -d c000:0090

The above line will give you a dump similar to the above example however may have additional information about the video card.

Debug Script To Remove DOS Partitions (FAT16 & Fat32)

Warning! This will erase all data on the hard drive.

Debug Script To Remove NON-DOS Partitions (Linux, NTFS & Windows 2000) 

Warning! This will erase all data on the hard drive.

ERASE HDD AND CLEAR CMOS

This routine is useful in clearing DDO and removing possible viruses. If this routine completes successfully it will erase everything from your Hard drive as well as your reset your CMOS values. In the following debug routine only type what is in bold from line 3 to 17. You will get a response if it corresponds with the following.

When your computer comes back on from doing the above you will get an error message as booting up the computer such as "Invalid Configuration" you must enter CMOS and set the time and date save and reboot again. Once rebooted you will then need to run fdisk and recreate the partitions. Once created you will then need to format the hard drive and proceed as normal.

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