ASCII conversion
The system performs ASCII conversion on all ISO/ANSI labels, all user data on Version 1 and 3 tapes and user data on Version 4 tapes when Coded Character Set Identifier (CCSID) conversion is not done. The system also performs ASCII conversion on unlabeled tapes if you specify OPTCD=Q in the DCB or DD statement. The system performs CCSID conversion if the application program or the data set has the CCSID option.
The IBM-supplied conversion routine converts ASCII 7-bit code and is designed to support Version 3 or Version 4 standards. The system forces OPTCD=Q during the open routine to cause ASCII conversion during processing of any volume mounted as LABEL=AL.
Additional information on ASCII 7-bit code and tables showing the relationship of EBCDIC and ASCII 8-bit code is given in Equivalent ASCII and EBCDIC codes.