What _dos_setdrive() Returns as the Number of Drives

Last reviewed: July 17, 1997
Article ID: Q42461

5.10 6.00 6.00a 6.00ax 7.00 | 1.00 1.50

MS-DOS                      | WINDOWS

kbprg

The information in this article applies to:

The C Run-time (CRT), included with:

    - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, and 6.0ax
    - Microsoft C/C++ for MS-DOS, version 7.0
    - Microsoft Visual C++ for Windows, versions 1.0 and 1.5

The run-time function _dos_setdrive() takes two arguments, as follows:

   void _dos_setdrive( unsigned drive, unsigned *numdrives)

The "numdrives" argument receives the number of possible drives in the system. With MS-DOS versions 1.x and 2.x, this value is 2, since two logical drives (A and B) are supported on a single floppy-disk drive. With MS-DOS 3.0 or greater, the value returned is 5 or the number set with LASTDRIVE in the CONFIG.SYS, whichever is greater.

This information is returned from interrupt 21h, function 0Eh.

Additional reference words: kbinf 5.10 6.00 6.00a 6.00ax 7.00 1.00 1.50
KBCategory: kbprg
KBSubcategory: CRTIss
Keywords : kb16bitonly

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Last reviewed: July 17, 1997
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