byte-integer-source-string
    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor
    String (EBCDIC) to be translated by LIB$TRA_EBC_ASC. The
    byte-integer-source-string argument contains the address of a
    descriptor pointing to this source string.
 destination-string
    OpenVMS usage:char_string
    type:         character string
    access:       write only
    mechanism:    by descriptor
    Destination string (ASCII). The destination-string argument
    contains the address of the descriptor of this destination
    string.
    The LIB$TRA_EBC_ASC routine uses the EBCDIC to ASCII translation
    table, LIB$AB_EBC_ASC.