LABELING MAGNETIC MEDIA

We use two types of labels for magnetic media. The first type is placed on the outside of the media itself and

Figure 2-3.\Damaged disk dust cover.

Figure 2-4.\Checking for BOT and EOT with read/write head.

is referred to as an external label. External labels are the labels we are interested in. The second type is written directly onto the media and is referred to as an internal label. Internal labels contain information that is needed by the executive control programs (systems software) of the computer to allow for the proper functioning of applications programs.

External Labels

External labels are considered permanent or nonpermanent, depending on their purpose (see figure 2-5). The two types of permanent tape and disk labels are the identification label, which indicates the number that has been assigned to the media; and the certification label, which indicates the last time the media was certified (tested for its reading and writing capability). Nonpermanent labels include usage labels to tell you how often the media has been used on the computer, cleaning labels to indicate when and how often the media has been cleaned, and save labels to indicate the file or files that are contained on the media. As the magnetic media librarian, you are responsible for initiating and maintaining the first four types of external labels: identification, certification, usage, and cleaning

Figure 2-5.\Examples of media labels.

labels. The programmer, user, or control clerk is responsible for the save label.

PERMANENT LABELS.\ The permanent-type label comes with a special adhesive backing; and when applied to a surface such as the flange of a magnetic tape, it adheres permanently. That is not to say this type of label cannot be removed, but to remove it takes a considerable amount of effort. Normally, you would consider using this type of label only if it were to remain on the media throughout its life cycle, as is the case with the identification number or certification labels.

Identification Label.\ The identification number (label) contains a series of letters and/or numbers (usually from 3 to 8 characters in length) that tell you where the magnetic media resides in the library (see figure 2-5). It is a permanent home address, you might say. Your responsibility is to ensure that whenever new tapes and disks are brought into the library be properly numbered. If the tape or disk is a replacement for one that is no longer usable, you must be sure to dispose of the old media and physically remove the identification label.

Certification Label.\ The certification label is used to indicate the last time a magnetic tape or disk underwent certification. Diskettes are not normally certified, but, instead, are disposed of upon receiving an unacceptable number of unrecoverable read/write errors. It has been found to be more cost effective to simply replace this type of media with new rather than putting it through a refurbishing process.