Device Requests

                                  DOS

     Cmd Name                     Ver. Usage Flags

     ßßß ßßßßßßßßßßßßßßßßßßßßßßßß ßßßß ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

     00H Initialize device             

     01H Media Check                        

     02H Build BPB                          

     03H IOCTL Input                   

     04H Input (read from device)      

     05H Non-destructive Input         

     06H Input status                  

     07H Input Flush                   

     08H Output (write to device)      

     09H Output with verify            

     0aH Output Status                 

     0bH Output Flush                  

     0cH IOCTL Output                  

     0dH Device Open              3.0+      

     0eH Device Close             3.0+      

     0fH Removable Media          3.0+           

     10H Output until busy        3.0+                     

     13H Generic IOCTL Request    3.2            

     17H Get Logical Device       3.2                 

     18H Set Logical Device       3.2                 

     19H IOCTL Support Query      5.0                 

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 On entry to the Strategy routine (see Device Driver Basics), DOS passes

 the address of a request structure in ES:BX (see DevRequestHdrRec).  The

 bCmd field of that structure (at offset 2) will contain one of the above

 command codes.



 The variable-length data that follows the DevRequestHdrRec varies from

 command to command.  Some commands share identical request structures.

 Others have a unique structure and some use only the request header to

 communicate with DOS.



See Also: IOCTL Functions

          Device Attribute

          Device Status Word

          Installable Device Drivers

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