INT 0x13 AH=0x48 returned CF=1

allen2010 · **Joined:** Mon May 01, 2023 5:56 pm **Posts:** 1

I want to read disk parameters. This is my code:

Code:

int13ah48:
      MOV      DWORD [0xc000],0
      MOV      DWORD [0xc004],0
      MOV      DWORD [0xc008],0
      MOV      DWORD [0xc016],0
      MOV      AH,0x48
      MOV      DL,0x80
      MOV      CX,0
      MOV      DS,CX
      MOV      SI,0xc000
      
      INT      0x13
      JC      fin
      MOV      [0xc000],AH
int13ok:
      RET

fin:
      JMP      fin

I ran it on VMware and Bochs, CF set and AH set to 0x1. Why?

Octocontrabass · **Joined:** Mon Mar 25, 2013 7:01 pm **Posts:** 5146

allen2010 wrote:

Code:

MOV DWORD [0xc000],0

You need to tell the BIOS how big your buffer is. The minimum buffer size is 26 (0x1A) bytes. You're telling the BIOS your buffer is 0 bytes.

OSDev.org

INT 0x13 AH=0x48 returned CF=1

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