How to solve this problem when deleting a file in assembler 8086?

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Hello everyone, the reason for this post is to see if something can be done regarding this code, what happens is that I cannot delete a file as long as the 3CH function to create it is executed with INT 21H.

ASM

;Enter the file name
MOV AH, 0AH 
LEA DX, NMF
INT 21H
MOV BL, NMF[1]
MOV NMF[BX + 2], ' '

;Create the file
MOV AH, 3CH  
MOV CX, 0H  
LEA DX, NMF + 2 
INT 21H
MOV HND, AX

;Close the file
MOV AH, 3EH
MOV BX, HND
INT 21H

;Delete the file
MOV AH, 41H
LEA DX, NMF + 2 
INT 21H

NMF and HND are defined as follows.

ASM

NMF DB 100 DUP(' '), 0
HND DW 0

And it is worth mentioning that the CF = 0 and AX = 00003 at the time of launching the interrupt to delete the file, so I would not know if it is an error since CF is not 1. I hope and you can help me, thank you.

What I have tried:

I did test and remove the execution of the interrupt to create a file and if the delete works if I put in NMF the name of a file directly, and when I try again executing the create interrupt with the direct name in NMF it stops working.

Posted 25-Oct-21 4:21am

Berserker Knight

Updated 25-Oct-21 9:47am

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Richard MacCutchan · Answer 1 · 2021-10-25T09:47:00

I cannot quite see how your path is set up but it does not look quite correct. You need to put the maximum length of the buffer in byte 0 before you call the create function. You then need to store zero in the byte after the last character of the string (not a space):

ASM

MOV NMF[0], 100
MOV AH, 0AH 
LEA DX, NMF
INT 21H
MOV BL, NMF[1]
MOV NMF[BX + 2], 0

NB it is more than 30 years since I last wrote 8080 assembler so I apologise for any syntax errors.