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Tape files

The current version of EPIO will recognize when it reads or writes a tape instead of disk, provided the device name is of the standard form MTAn:

For example: Suppose you want to mount a tape with blocks of length 23040 bytes on unit 0, for the logical unit no. 1:

MOUNT /FOR/BLOC=23040/REC=23040 MTAn: LABEL FOR001

where LABEL is just a place holder. For unlabelled tapes, on the CENTRAL 8600 at CERN the command should read

SETUP/BLOC=23040/REC=23040/NOLABEL XUTnnn XUTnnn FOR001

for a non labelled tape, where the second XUTnnn is again a place holder. Should the tape be labelled the qualifier /LABEL=ASCII or /LABEL=EBCDIC is required. If the tape is to be written the qualifier /WRITE must be inserted before the /[NO]LABEL qualifier. Byte swapping to/from tape may be done automatically when using EPIO, if this is allowed by the drivers' firmware/hardware. Tapes with EBCDIC labels should be positioned correctly using e.g.:

SET MAGTAPE/SKIP=FILES:1 FOR001

Alternately label groups must be treated by the user by recovering from EPIO error 5. The file name may be changed at run-time via a call to the routine EPDEFU.  


Janne Saarela
Tue May 16 09:44:28 METDST 1995