en:docs:dos:api:int21:36

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en:docs:dos:api:int21:36 [2020/12/11 05:53] (current)
prokushev created
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 +{{page>​en:​templates:​dosint}}
 +
 +====== Int 21H, AH=36H ======
 +
 +===== Version =====
 +
 +2 and higher
 +
 +===== Brief =====
 +
 +GET FREE DISK SPACE
 +
 +===== Family API =====
 +
 +
 +===== Input =====
 +
 +        AH = 36h
 +        DL = drive number (00h = default, 01h = A:, etc)
 +
 +===== Return =====
 +
 + AX = FFFFh if invalid drive
 +        else
 +            AX = sectors per cluster
 +            BX = number of free clusters
 +            CX = bytes per sector
 +            DX = total clusters on drive
 +
 +===== Notes =====
 +
 +  free space on drive in bytes is AX * BX * CX
 +        total space on drive in bytes is AX * CX * DX
 +        "lost clusters"​ are considered to be in use
 +        according to Dave Williams'​ MS-DOS reference, the value in DX is
 +          incorrect for non-default drives after ASSIGN is run
 +        this function does not return proper results on CD-ROMs;
 +          use AX=4402h"​CD-ROM"​ instead
 +        (FAT32 drive) the reported total and free space are limited to 2G-32K
 +          should they exceed that value
 +          ​
 +===== See also =====
 +
 + ​AH=1Bh,​AH=1Ch,​AX=4402h"​CD-ROM",​AX=7303h
 +
 +===== Note =====
 +
 +Text based on [[http://​www.cs.cmu.edu/​~ralf/​files.html|Ralf Brown Interrupt List Release 61]]
 +
 +{{page>​en:​templates:​int}}
 +
 +{{page>​en:​templates:​fapi}}
  

en/docs/dos/api/int21/36.txt · Last modified: 2020/12/11 05:53 by prokushev