Loading and Unloading Tapes When you are loading or unloading (mounting or dismounting)  a  magnetic  tape,  look  for  tapes  with irregular windings and reel warpage. You will see that as tape is wound on a reel, it is normal for some of its edges to protrude slightly. These irregularities usually result from high-speed rewinding. The terrific speed at which tape moves during a high-speed rewind produces the   slightly   irregular   winding   caused   by   air   being trapped between adjacent layers of tape. This, in itself, will not cause improper operation of the tape, but it does require  you  to  use  good  judgment  and  extreme  care when handling tapes. MOUNTING A TAPE.— When you mount a tape, make sure the tape unit is not being used for another job. Check to make sure you are mounting the correct reel of tape according to job requirements. Tapes have external labels  that  identify  the  data  or  programs  on  them. Remember, if the reel of tape is an input, be sure the file protection ring is removed. If the tape is an output, be sure a file protection ring is inserted. Then proceed to mount the tape. Have one of the more senior operators on the system show you how to perform this operation because  mounting  a  tape  and  depressing  the  proper keys/buttons   differ   from   one   system   to   another. Basically, you will place the reel on a hub and lock the reel  in  place. Then  you  thread  the  tape  through  the read/write  head  assembly  onto  the  machine  take-up  reel (unless the tape unit is a self-loading tape unit). Once the tape is properly loaded, the ready light comes on. If the tape is not properly seated on the tape unit’s hub during use, it will wobble or appear to be warped. If the file protection ring is not completely inserted, this, too, can produce the same effect. In either case, the reel behaves like it is warped, and upon rewinding, the edges of the tape can become badly damaged. Self-Loading   Tapes.— The  use  of  self-loading tapes  makes  tape  loading  much  easier.  Self-loading tape units eliminate the need for you to manually thread a tape between the read/write head assembly onto the machine take-up reel. All you need to do is to mount (place) the reel of input or output tape on the file reel hub and allow a small strip of tape to extend from the reel (anywhere from 2 to 6 inches, depending on the type of tape unit). Then, by depressing the proper control panel keys/buttons in the appropriate sequence, the tape unit automatically threads the tape by using a vacuum to pull the  tape  into  the  vacuum  column  past  the  read/write head   assembly   onto   the   machine   take-up   reel   and advances to the load-point (BOT) marker. Tape  Cartridges.—Tape  cartridges  are  even  easier to load. Tape cartridges consist of a reel of tape and a take-up reel enclosed in a protective case similar to the cassette tapes you are familiar with, only larger. Here, you simply mount the entire tape cartridge on the tape unit  and  depress  the  proper  keys/buttons.  The  tape automatically loads. Your hands never come in contact with the tape. The cartridge type of tape unit also works under vacuum control and threads the tape in the same manner as self-loading tape units. DISMOUNTING A TAPE.—  When a job finishes using a tape, the tape is normally rewound and unloaded automatically.  At  that  time,  the  ready  light  goes  off. This  is  an  indication  to  you  that  the  tape  can  be dismounted  and  placed  in  its  proper  storage  rack  or returned to the media library. LABELING A TAPE.— In some installations, you may be required to prepare the external tape label for an output   tape   file. On   it,   you   will   indicate   such information as the following: l l l l e The tape unit number (or drive number) where the tape file was initially created The date of creation The job name or number The identification or volume number The   tape   usage   data   and   other   pertinent information STORING TAPES.— When not being used, tape reels  should  be  properly  supported.  The  plastic  canister or tape strap is designed to fully support the reel. A tape reel that is supported in any other manner may become warped. 2-31