Initializing a magnetic tape (example)

(OUT) % NVI0001 ENTER COMMAND. (END = TERMINATE INIT)
(IN) INIT TAPE-C4,VSN=TAPE1,ERASE                                         1.
(MSG) %  NKVT013 MOUNT TAPE '*SCRAT' ON DEVICE 'T9';                      2.
                 (USE='SPECIAL',WR='UNDEF',TYPE='TAPE-C4',
                 INIT T-C4,VSN=TAPE1).
                '(ETX = YES; MN; N = NO )'?
(IN)  0ABC.T7
(OUT)  % NVI0003 LABELS ON TAPE (ISO7):                                   3.
(OUT)  % NVI0004 VOL1 LABEL:
              'VOL1TAPE01                              '
                '                                       1'
(OUT)  % NVI0004 HDR1 LABEL:
                 'HDR1SAMPLE.FILE   TAPE010001000100010'
                 '0 92104 92104 000000BS2000              '
(OUT)  % NVI0004 HDR2 LABEL:
                 'HDR2V8000102044 0                 P     '
                 '      .C..04                            '
(OUT)  % NVI0004 HDR3 LABEL:
                 'HDR3TSOS    SAMPLE.FILE                 '
                 '                ............00          '
(OUT)  %  NVI0007 OVERWRITE TAPE?                                         4.
                  REPLY (YES=YES N=NO)
(IN)   YES
(OUT)  %  NVI0208 DATA SECURITY ERASE STARTED                             5.
(OUT)  %  NVI0209 DATA SECURITY ERASE COMPLETED
(OUT)  %  NVI0210 INITIALIZATION OF TAPE 'TAPE1'                          6.
                  ON DEVICE 'T7' COMPLETED
(OUT)  %  NVI0001 ENTER COMMAND. (END = TERMINATE INIT)                   7.

1. To initialize a volume, enter INIT with a unique valid volume type (in this case with ERASE is specified (data security erase)).

2. Message output via the console requests the operator to mount the volume. Once the volume is mounted (on device T7 in this case), the operator confirms by specifying the task sequence number (TSN). If the volume is mounted on the device specified in the MOUNT request (T9), the mnemonic device name (T7) can be omitted.

3. The volume is read and the labels, if any, are output. If the labels are written in ISO7 code, the output includes a message to this effect. In this example, the contents of the labels are spread over a number of lines and are delimited by quotation marks. In normal use, the contents of the labels are output as a single string; blanks at the end of the string are not included.

   If the volume has no volume label (VOL1) or the label is invalid, explanatory messages are issued instead of the labels.

   Empty volume:

   (OUT) % NVI0102 NO LABELS ON TAPE. TAPE EMPTY

   Tape marks at the beginning of the volume:

   (OUT) % NVI0103 NO LABELS ON TAPE. TAPE MARKS READ

   Error when reading VOL1 label :

   (OUT) % NVI0104 I/O-ERROR WHILE READING LABELS

4. This is followed by the question whether or not to overwrite the volume. This is the last opportunity to prevent the volume being overwritten. If the answer is affirmative, the word YES (for overwrite) must be typed in full. For safety’s sake, abbreviations are rejected. All other entries (i.e. do not overwrite) are interpreted as negatives.

5. If data security erase was requested by the ERASE parameter, the data on the volume is erased. This procedure can take several minutes or hours, depending on the device and the volume; messages are output to indicate the start and end of the process.

6. After deletion, the new labels are written and a message is output indicating that initialization is completed. If initialization is unsuccessful, a message is output indicating the source of the problem and initialization is aborted.

   (OUT) % NVI0309 TAPE WITH VSN ' ' CANNOT BE USED.
                INITIALIZATION ABORTED

7. The system prompts for the next statement.