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Chapter 5 - AppleTalk Data Stream Protocol (ADSP) / ADSP Reference

Data Structures

The ASDSP Parameter Block

To open an ASDSP connection, the client application at each end must call the Device Manager's PBControl function with a command code that specifies the ASDSP open routine (sdspOpen). This section describes the ASDSP parameter block whose pointer you pass to PBControl to execute the sdspOpen routine. The ASDSP parameter block contains fields that carry the input and output parameters associated with the function. The SDSPParamBlock data type defines the ASDSP parameter block.

For a description of the fields that are common to both the DSP and ASDSP parameter blocks and that are used in exactly the same way, see "The DSP Parameter Block" beginning on page 5-38. For a description of the fields that are particular to the sdspOpen routine, see "sdspOpen" beginning on page 5-54.

SDSPParamBlock = 
PACKED RECORD
CASE INTEGER OF
   1: (dspParamBlock: DSPParamBlock);
   2: (qLink:        QElemPtr;         {reserved}
      qType:         Integer;          {reserved}
      ioTrap:        Integer;          {reserved}
      ioCmdAddr:     Ptr;              {reserved}
      ioCompletion:  ProcPtr;          {pointer to completion routine}
      ioResult:      OSErr;            {routine result}
      ioNamePtr:     StringPtr;        {reserved}
      ioVRefNum:     Integer;          {reserved}
      ioCRefNum:     Integer;          {ASDSP driver refNum}
      csCode:        Integer;          {ASDSP driver control code}
      qStatus:       LongInt;          {reserved}
      ccbRefNum:     Integer;          {connection end refNum}
      secureParams:  TRSecureParams);  {dspOpenSecure}
END;
SDSPPBPtr = ^SDSPParamBlock;

Field Description

csCode

The command code for the ASDSP routine to be executed. You must fill in this field before calling the PBControl function. To call the sdspOpen routine to open a secure connection, you specify the constant sdspOpen as the value of this parameter.

secureParams

A record of type TRSecureParams that contains the additional parameters required to open a secure ASDSP session.