
Tape Processing BIM-EPIC Job Control
1-40 User Reference
Tape Processing
Open, end-of-volume, and close processing are the most significant processing periods for
BIM-EPIC, and open processing is the most important of the three. In each case, processing is
different for tape and disk. Each is discussed separately. When a tape dataset is opened,
BIM-EPIC carries out the following tasks:
BIM-EPIC determines whether a dataset is tape or disk by checking the JCL and the DSN
Catalog.
BIM-EPIC determines whether the dataset is controlled. If it isn’t controlled, BIM-EPIC
passes control to VSE immediately. If the dataset is controlled, it reads the catalog entry to
determine how to process this version.
BIM-EPIC performs AVR processing by searching available drives for the correct input tape
or for a BIM-EPIC scratch tape for output.
If it doesn’t find an appropriate tape, it issues a message to the operator and waits for a
response.
When the tape is mounted, it assigns the drive to the requesting partition and attaches the drive
to the VSE machine if Autoattach is active.
It updates the DSN Catalog (creates a dataset definition if automatic cataloging is required and
records information about the version being created). The version is placed in open status.
BIM-EPIC updates the VSE Label Area. On input, it clears the dataset name from the label
and substitutes the correct volume serial number. On output, it adds a period to the VOL1
label to mark the tape as a BIM-EPIC tape and writes a 99365 expiration in the HDR1 label to
protect the tape against accidental overwrites.
BIM-EPIC passes control to VSE before the dataset is written. VSE then uses the information
BIM-EPIC has written in the VSE Label Area to process the dataset.
The steps performed in end-of-volume (EOV) processing are similar to those performed in
open processing. BIM-EPIC sets the stage for reading or writing the next tape. In EOV
processing, BIM-EPIC must gain and pass control to VSE more than once.
BIM-EPIC releases the assignment made for the drive that was just used and detaches the tape
drive from the VSE machine if Autoattach is active.
It performs AVR for the next volume.
If it can’t locate the volume, it issues a message to the operator.
When the tape is mounted on an available drive, BIM-EPIC assigns and attaches the drive.
It updates the DSN Catalog. On output, it writes another volume record for the version, places
that volume in open status, and places the previous volume in conditional catalog status. On
input, it updates date last accessed, use count, and other statistical information.
Open Processing
End-of-Volume
Processing
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