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include blockdev.inc
 
mov     ax,  CmdNum         ; command number
mov     edi, OFFSET32 bdd   ; points to a BlockDev_Device_Descriptor
VXDcall BlockDev_Synchronous_Command
 
The BlockDev_Synchronous_Command service sends a synchronous command to a
specified block device.
 
Parameter  Description
────────────────────────────────────────────────────────────────────────────
 
CmdNum     Specifies a command number. It can be one of the following:
 
           Value              Meaning
           ─────────────────────────────────────────────────────────────────
           BD_SC_Get_Version  Retrieves the version number for the block
                              device.
 
bdd        Points to a BlockDev_Device_Descriptor structure.
 
Return Value
 
If the carry flag is clear, the EAX, EBX, ECX, EDX, ESI, EDI, and flags are
modified as defined by the command. Otherwise, the carry flag is set and the
AX register contains the following error value:
 
Value  Meaning
────────────────────────────────────────────────────────────────────────────
BD_SC_Err_Invalid_Cmd
       Invalid synchronous command
 
Comments
 
Registers in addition to AX and EDI may be used as parameters for specific
commands.
 
Uses
 
Registers defined by command and flags
 
See Also
 
BlockDev_Device_Descriptor
 
 
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