Triton Isis - Manual (Page 46)

June 2004 Isis® Sonar User's Manual, Volume1 32
You can, of course, use a text editor to inspect or modify a RUN file, such as
changing the order of the listed files or deleting or adding an entry.
To play back a batch file in Isis
• Open a RUN file just as you would any other file for Isis playback.
See ‘Playing Back Data Sets from Disk or Tape’ .
3.2 Working with SCSI Tape
Isis supports real-time data storage and playback to and from any sequential
SCSI device. A typical example is an Exabyte tape drive, but there is no check in
Isis software for any particular brand or model. Isis simply sends sequential
device instructions over the SCSI bus. As long as a tape drive complies with
SCSI-1 or later specifications, there should be no compatibility problems.
While recording or playing back to tape, Isis uses a portion of your hard disk to
temporarily store data. You should have at least 200 megabytes of free disk
space available in order to log to tape with Isis.
3.2.1 Block Size on Tape
Isis does not specifically set the drive’s block size. Typically, the block size
of a tape drive defaults to 1024 bytes. All read and write requests to and
from the tape drive are done in blocks of 1024 bytes. This is done to
maximize the drive’s data rate.
Note that any SEG-Y files recorded by Isis versions prior to v2.21 can be
read only by previous versions of Isis. This is because previous Isis versions
enforced the SEG-Y specification of varying the block size within a SEG-Y
file. Isis version 2.21 and later write data on the tape in a stream of 1024-
byte blocks exactly as it is read from disk.
3.2.2 Filemarks
Filemarks are written to the tape whenever:
• Recording was interrupted (Stop was pressed).
• A tape has been written to and is about to be rewound or ejected.
• The file name changed during recording.
Chapter 3: Using the File Menu