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====== Int 21H, AH=37H, AL=03H ======

===== Version =====

2.x and 3.3+ only

===== Brief =====

set availdev flag

===== Family API =====



===== Input =====

        AH = 37h
        AL = 03h set availdev flag
                DL = new state
                    00h         \DEV\ is mandatory
                    nonzero     \DEV\ is optional

===== Return =====

 AL = status
            00h successful
            FFh unsupported subfunction

===== Macro =====


===== Notes =====

all versions of DOS from 2.00 allow \DEV\ to be prepended to device names without generating an error even if the directory \DEV does not actually exist (other paths generate an error if they do not exist); DOS 2.x has an AVAILDEV= option in CONFIG.SYS to make \DEV mandatory
          
although MS-DOS 3.3+, DR DOS 3.41+, and Novell DOS 7 accept these calls, they have no effect, and AL=02h always returns DL=FFh (except for Novell DOS 7, which leaves AX unchanged for both subfunctions)

===== See also =====

AX=[[en:docs:dos:api:int21:37:02|3702h]]


===== Note =====

Text based on [[http://www.cs.cmu.edu/~ralf/files.html|Ralf Brown Interrupt List Release 61]]

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