x86 - How to save the result on the screen into a text file in assembly language? -

I do not understand this, I need your help and I should also know this. Sorry for the English language, I do not do it well.

  Organization 100 H. Model Small Enter DATA MSG DB 0DH, 0 AH, 'STRING: ----- & gt; : $ 'MSG2 db 0h, 0h,' Your STRING is: -----> : $ 'STR 1 DB 255 DUP (?) A DB? Two db? .CODE BEGIN: MOV AX, @ data mov ds, exe lo dx, msg mov ah, 09 h int 21 llia, str 1 mov ah, 01 h rad: int 21 h mow bl, al cmp al, 0 dh JEE Performance XOR AL, 20HMOV [SI], AL Congress SI, CMP BL, 0H JMP Reed Display: MOV AL, '$' MOV [SI], LLE DX, MSG 2 MOV AH, 09H INAT 21LL AXX, STR 1 MOV AH, 09H INT 21H; MOV AH, 4CH; INT 21H .EXIT END Start    
 
 
 You should be able to read the start of screen memory at the address  B800: 0000 .  
 Check out:  
 And, more specifically:  
 To create and write the file check out:   < / Html>