/*

**  Apple Macintosh Developer Technical Support

**

**  Sample code demonstrating detecting CD-ROM drives

**

**  by Brian Bechtel, Apple Developer Technical Support

**

**  File:       WhereCDs.c

**

**  Copyright © 1995 Apple Computer, Inc.

**  All rights reserved.

**

**  You may incorporate this sample code into your applications without

**  restriction, though the sample code has been provided "AS IS" and the

**  responsibility for its operation is 100% yours.  However, what you are

**  not permitted to do is to redistribute the source as "DTS Sample Code"

**  after having made changes. If you're going to re-distribute the source,

**  we require that you make it clear in the source that the code was

**  descended from Apple Sample Code, but that you've made changes.

*/

#include <Devices.h>

#include <TextUtils.h>

#include "WhereCDs.h"

// From tech note DV 22, CD-ROM Driver Calls.  Detects drives which

// are using the driver name ".AppleCD" in the range of driver

// reference numbers assigned to the original SCSI bus.  Will not

// handle drives which aren't using a driver named ".AppleCD", nor

// drives on additional SCSI buses.

UInt8 WhereCDs() 

{ 

    UInt8       where = 0; /* assume no drives handled at beginning */

    short       scsiAddress; 

    short       drvrRefNum; 

    DCtlHandle  aDCtlEntry; 

    StringPtr   aDriverName; 

    StringPtr   appleDriverName = "\p.AppleCD";

    for (scsiAddress = 0; scsiAddress < 7; scsiAddress++) 

    { 

        drvrRefNum = -33 - scsiAddress;

        aDCtlEntry = GetDCtlEntry(drvrRefNum); 

        if (aDCtlEntry != nil) 

        { 

            if ((**aDCtlEntry).dCtlFlags & dRAMBasedMask) 

                aDriverName = (StringPtr) ((*(DCtlPtr)aDCtlEntry).dCtlDriver+18); 

            else 

                aDriverName = (StringPtr)((**aDCtlEntry).dCtlDriver+18); 

            if ( EqualString(aDriverName, appleDriverName, false, false) == true ) 

                where |= (1 << scsiAddress); 

        }

    }

    return where; 

}