en:docs:dos:api:int21:44:0d

Note: This API call is for DOS personality only. Use Family API for portability.

2018/09/07 07:04 · prokushev

Int 21H, AH=44H, AL=0DH

Version

3.2 and higher

Brief

GENERIC BLOCK DEVICE REQUEST

Family API

Input

AX = 440Dh
BL = drive number (00h=default,01h=A:,etc)
CH = category code (see #01558)
CL = minor code (function) (see #01559)
DS:DX -> (DOS) parameter block (see #01560,#01562,#01563,#01564,#01565)
SI:DI -> (OS/2 comp box) parameter block (see #01566,#01568,#01569,#01572)

Return

 CF set on error
    AX = error code (01h,02h,etc.) (see #01680 at AH=59h/BX=0000h)
CF clear if successful
    DS:DX -> data block if CL=60h or CL=61h

Macro

Notes

  	DOS 4.01 seems to ignore the high byte of the number of directory
  entries in the BPB for diskettes.
functions 46h and 66h undocumented in DOS 4.x, documented for DOS 5+
the DUBLDISK.SYS v2.6 driver only supports minor codes 60h and 67h
DR DOS 3.41-6.0 only support minor codes 40h-42h and 60h-62h; all
  other minor codes return error code 16h
some PCMCIA calls reportedly appear to be dangerous for MS-DOS versions
  prior to 5.0
minor code 60h normally produces no I/O except with AutoMount=1 for
  DBLSPACE/DRVSPACE

See also

  AX=440Ch,AX=440Dh/CX=084Ah,AX=440Dh/CX=0871h,AH=69h,INT 2F/AX=0802h, INT 2F/AX=122Bh

Note


en/docs/dos/api/int21/44/0d.txt · Last modified: 2021/05/01 17:08 by prokushev