Processing QSAM ASCII files on tape

In addition, if your program processes signed numeric data items from ASCII files, define the numeric data as zoned decimal items with separate signs, that is, as USAGE DISPLAY and with the SEPARATE phrase of the SIGN clause.

The CODEPAGE compiler option has no effect on the code page used for conversions between ASCII and EBCDIC for ASCII tape support. For information about how CCSIDs used for the ASCII tape support are selected and what the default CCSIDs are, see the z/OS® DFSMS documentation.

Requesting the ASCII alphabet: In the SPECIAL-NAMES paragraph, code STANDARD-1 for ASCII:

ALPHABET-NAME IS STANDARD-1

In the FD entry for the file, code:

CODE-SET IS ALPHABET-NAME

Defining the record formats: Process QSAM ASCII tape files with any of these record formats:

• Fixed length (format F)
• Undefined (format U)
• Variable length (format V)

If you use variable-length records, you cannot explicitly code format D; instead, code RECORDING MODE V. The format information is internally converted to D mode. D-mode records have a 4-byte record descriptor for each record.

Defining the ddname: Under z/OS, processing ASCII files requires special JCL coding. Code these subparameters of the DCB parameter in the DD statement:

BUFOFF=[L|n]

L

A 4-byte block prefix that contains the block length (including the block prefix)

n

The length of the block prefix:

• For input, from 0 through 99
• For output, either 0 or 4

Use this value if you coded BLOCK CONTAINS 0.

BLKSIZE=n

n

The size of the block, including the length of the block prefix

LABEL=[AL|AUL|NL]

AL

American National Standard (ANS) labels

AUL

ANS and user labels

NL

No labels

OPTCD=Q

Q

This value is required for ASCII files and is the default if the file is created using Enterprise COBOL.