MAS-Initialized Tape Volume Format

In general, virtual tape volumes initialized by the MAS comply with the format of tapes initialized by the MVS utility IEHINITT.

IBM Standard (SL) Labels

The format for IBM Standard (SL) Labels created by the MAS is:

1. A VOL1 label containing the volume serial number.
   In addition, the MAS places an identifier in the VOL1 label for the benefit of various tape management systems:
   
   • By default, the EBCDIC characters 'TCSBT' are placed in positions 56-60.
   • If the parameter EPIC=YES is specified during initialization, positions 56-60 will be blanks and position 61 will contain an EBCDIC '.' (period).
2. A dummy HDR1 label with 'HDR1' followed by 76 EBCDIC zeros.
3. A single tapemark.

The following is a character and hex dump of the default IBM Standard (SL) Labels created by a MAS:

The following is a character and hex dump of the IBM Standard (SL) Labels created by a MAS with EPIC=YES specified during initialization:

ANSI (AL) Labels

The format for ANSI (AL) Labels created by the MAS is:

1. A version 4 VOL1 label containing the volume serial number, and an ASCII character '4' in position 80.
   In addition, the MAS places an identifier in the VOL1 label for the benefit of various tape management systems:
   
   • The EBCDIC characters 'TCSBT' are placed in positions 38-42.
   • The parameter EPIC=YES is not supported by the MAS for initialization of ANSI labels.
2. A dummy HDR1 label with ASCII zeros in the rest of the label except:
   • '0001' in the section, sequence, and generation number fields (positions 28-31, 32-25, and 36-39 respectively).
   • A leading space in the creation and expiration dates (positions 42 and 48 respectively).
   • A space in the accessibility field (position 54).
   • 'IBMZLA       ' in the system code (positions 61-73).
3. A single tapemark.

The following is a character and hex dump of the default ANSI (AL) Labels created by a MAS:

Unlabeled Volumes

The MAS initializes unlabeled volumes by writing five (5) tapemarks at the beginning of the volume.