Debug plays a very important role in the process of learning assembly and is an extremely important debugging tool, so it is necessary to learn it.
| command format | Function Description | |
| A | [address] | Enter assembly instructions |
| C | [range] start address | Compares the area specified by "Range" with the same size area specified by "Start Address" and displays the different units |
| D | [Scope] | Displays the contents of memory cells within the specified range |
| E | Address Byte Value Table | Replace the contents of the memory cell starting at "address" with the value in the value table |
| F | Range Byte Value Table | fills the memory area with the specified table of byte values |
| G | [=start address][breakpoint address] | Execute from the starting point (or current location) and end at the end point |
| H | value 1 value 2 | Displays the sum and difference of two hexadecimal values |
| I | port address | Input from port |
| L | [address [drive letter sector number of sectors]] | read from disk |
| M | range address | transfer byte values in "range" to the unit starting at "address" |
| N | file identifier [file identifier...] | Specify the filename to prepare for reading/writing the file |
| O | port address byte value | output to port |
| P | [=address] [number of instructions] | Press the execution process, but do not enter a subroutine call or soft interrupt |
| Q | Exit DEBUG without saving the file being debugged | |
| R | [register name] | Display and modify register contents |
| S | Range Byte Value Table | Searches the specified table of byte values within the memory area. If found, display the starting address, otherwise, display nothing |
| T | [=address] [number of instructions] | Trace execution, execute several instructions from the starting point (or current location) |
| U | [Scope] | Disassemble, display the assembly instructions corresponding to the machine code |
| W | [address [drive letter sector number of sectors]] | Write content to disk, (BX, CX) is the number of bytes written |
A few notes about the parameters:
1. Hex: The data entered or displayed in DEBUG are in hexadecimal form
2. Separation: Commands and parameters, parameters and parameters should be separated by spaces, commas or tabs, etc.
3. Address: The address is represented in the form of "segment value: offset", and segment register can also be used to represent "segment value",
for example: 1000:0, ds:10, es:200, cs:30, etc.
4. 范围：表示地址范围，它有二种表示方式：“地址1 地址2”和“地址1 长度”。
其中：“地址1”表示起始地址，要用“段值:偏移量”来表达；
“地址2”表示终止地址，只用“偏移量”来表示；
“长度”用字母’L’开头的数值来表示。
例如：100:50 100——段值为100，偏移量从50到100的内存区域；
100:50 L100——段值为100，偏移量从50开始的100个字节区域。
5. 端口地址：二位十六进制数值
6. 字节值：二位十六进制数值
7. 字节值表：由若干个字节值组成，也可以是用引号括起来的字符串
8. 驱动器号：0—驱动器A、1—驱动器B、2—驱动器C、3—驱动器D等