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Q39311: Use 0x80 to Access Drive C when Calling _bios_disk

Article: Q39311
Product(s): See article
Version(s): 5.00 5.10
Operating System(s): MS-DOS
Keyword(s): ENDUSER | S_QUICKC | mspl13_c
Last Modified: 29-DEC-1988

Question:

I am using the _bios_disk function to access my fixed disk. I have
initialized the drive parameter to 2 to specify my fixed-disk drive.
This function does not seem to be accessing my fixed disk. What am I
doing wrong?

Response:

The first floppy drive in a computer is identified as drive 0 with
additional floppy drives numbered sequentially. However, the first
fixed disk is identified as drive 0x80 (128 decimal) with additional
partitions numbered sequentially. Therefore, call _bios_disk with the
drive parameter set to 0x80 to access the first fixed disk.

The following is an example:

   Logical Drive    diskinfo.drive
         A                 0
         B                 1
         C                0x80
         D                0x81
         E                0x82
         .                 .
         .                 .
         .                 .

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