Basic knowledge of assembly language

Link to the original text —— SevenOne’Blog

Edit program steps

1. Edit the source program , extension .asm
2. assembly ： Turn the source program file into the target file , Target file extension .obj
3. Connect ： Turn the target file into an executable , Executable extension .exe

Instructions

1. mount

   mount  Target drive letter   Local drive letter 
   

2. Clear the screen ：cls

3. Delete file ：del file name

4. see file ：type file name

5. Assembly instruction ：masm file name

6. Connection instructions ：link file name

Programming

Create source program

1. Instructions edit

2. grammar

   edit  file name .asm
   

3. If the file already exists, open the file to continue writing , If it does not exist, a new file will be created .

Segment definition

1. Instructions ：segment( Start ) ends( end )

2. Paragraph name ： No more than eight characters

3. grammar

    Paragraph name  segment
   
    Paragraph name  ends
   

Segment Association

1. Instructions ：assume

2. type ：CS（ Code segment ）、DS（ Data segment ）、SS（ stack segment ）、ES（ Additional segment ）

3. grammar ：

   assume  type : Paragraph name 
   

4. example ： Define a code snippet , Segment name code

   code segment
   	assume cs:code
   code ends
   

Store value

1. Instructions ：mov

2. General registers ：AX、BX、CX、DX

3. grammar mo

   mov  General registers , value 
   

   • General registers ： Destination operands
   • value ： Source operands

End procedure

mov ah,4ch
int 21h

Instruction classification

1. Double operand instruction ： Separate the two parameters with commas , The one before the comma is called the destination operand , The one after the comma is called the original operand .
2. Single operand instruction
3. No operand instruction
4. In all double operand instructions , The destination operand and source operand types must match .
5. 8086 There must be registers in the instruction , In addition to immediate addressing .

debug Instructions

1. sign out ：q
2. see CPU register ：r
3. Disassembly instruction ：u
4. Execute program instructions ：g（g offset ）
5. View memory bill ：d