Copying Labeled Tapes

Instructions for copying to and from labeled tapes are given below, as well as an example of how to deblock a labeled tape.

Copying Files to Labeled Tapes

The default parameter NEXT specifies that a file is to be written to the current position on the tape. If this is a newly mounted tape, the position will be the beginning of the tape.

To copy a single file starting at the beginning of the tape:

Use the NEXT parameter in the FILE command describing the labeled tape. For example,
>:FILE LTAPE;DEV=TAPE;LABEL=TLABEL,,,NEXT;REC=-80,10,F,ASCII
Copy the first disk file to the tape, using an asterisk before the tape file name to backreference the file command. For example,
>FROM=FILEA;TO=*LTAPE EOF FOUND IN FROMFILE AFTER RECORD 19 20 RECORDS PROCESSED * * * 0 ERRORS

To copy a second file to the same labeled tape, specify the desired position of the file.

Enter a number, in this case 2, in place of the NEXT parameter in the FILE command.
>:FILE LTAPE;DEV=TAPE;LABEL=TLABEL,,,2;REC=-80,10,F,ASCII

Copy the file to the tape, using an asterisk before the tape file name to backreference the file command. For example,

   >FROM=SRCFILE;TO=*LTAPE



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS

To combine data from two disk files into a single file on tape, use an asterisk alone as the tofile in the command for copying the second disk file. For example,

   >FROM=FILEC;TO=*LTAPE



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS



   >FROM=FILED;TO=*



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS

The parameter ADDF specifies that a file is to be written following all existing files on the tape. To add a new file to a tape without overwriting existing files, perform the following steps:

Use the ADDF parameter in the MPE FILE command. ADDF positions the tape drive after the last file on the tape. For example,
>:FILE LT2=FILE4;DEV=TAPE;LABEL=TLABEL,ANS,,ADDF

Copy the file to the tape, preceding the tofile name with an asterisk to backreference the FILE command. For example,

   >FROM=FILEF;TO=*LT2



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS

Copying Files from Labeled Tapes

You may copy a particular file from a labeled tape by using its number or its file name. When reading a labeled tape, it is usually not necessary to specify the record structure of the tape file in a file equation because the information is read from the labels.

Copying Files by Number

You can copy a file from labeled tape using its number, as follows:

Specify its file number in a FILE command. For example, the command below specifies the third tape file:
>:FILE LT;DEV=TAPE;LABEL=TLABEL,ANS,,3
Copy the file from the tape, preceding the fromfile name with an asterisk to backreference the FILE command. For example,
>FROM=*LT;TO=NEWDISK;NEW EOF FOUND IN FROMFILE AFTER RECORD 19 20 RECORDS PROCESSED * * * 0 ERRORS

Copying Named Files

You can also copy a named file from a labeled tape by using its name, as follows:

Specify the file name in the MPE FILE command describing the tape file. For example, the command below specifies a file named FILE4:
>:FILE LTNAME=FILE4;DEV=TAPE;LABEL=TLABEL,ANS,,0

In the FCOPY command, backreference the FILE command by preceding the fromfile name with an asterisk. For example,

   >FROM=*LTNAME;TO=FILED;NEW



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS

Concatenating Files from a Labeled Tape

You can concatenate files from a labeled tape into a single file, as follows:

Use the NEXT parameter in the MPE FILE command describing the tape. For example,



   >:FILE LTAPE;DEV=TAPE;LABEL=TLABEL,ANS,,NEXT;REC=-80,10,F,ASCII

In your FCOPY command, backreference the FILE command by preceding the fromfile name with an asterisk. To copy the labeled tape files to a single file, use the FCOPY FILES function.

   >FROM=*LTAPE;TO=CONCAT;FILES=4



   EOF FOUND IN FROMFILE AFTER RECORD 19



   20 RECORDS PROCESSED * * * 0 ERRORS



   EOF FOUND IN FROMFILE AFTER RECORD 29



   30 RECORDS PROCESSED * * * 0 ERRORS



   EOF FOUND IN FROMFILE AFTER RECORD 19



   20 RECORDS PROCESSED * * * 0 ERRORS



   EOF FOUND IN FROMFILE AFTER RECORD 9



   10 RECORDS PROCESSED * * * 0 ERRORS

Deblocking Labeled Tapes

You can read and deblock labeled tapes with blocked odd-byte records similarly to unlabeled tapes.

It is necessary to specify the tape characteristics as undefined records so that the byte count in the header labels will be ignored. For example, if the tape has 133-byte records, blocked in twenty-record blocks, you can deblock the records as follows:
>FILE LTAPE;DEV=TAPE;LABEL=TLABEL;REC=-2660,1,U,ASCII
In the FCOPY command, set DEBLOCK equal to the original record length.
>FROM=*LTAPE;TO=EVENBYTE;DEBLOCK=-133;NEW

Note that this method is not necessary with labeled tapes created on MPE. MPE always specifies an even byte count in the header label if there is more than one record per tape block.