The Abbey Newsletter

Volume 20, Number 6
Nov 1996

NARA Conference on Preserving Tapes & Disks, March 1996

Facts and Advice from the Speakers

by Ellen McCrady

With apologies to the speakers, I will use an unconventional but time-saving method of reporting this conference: simply transcribing from my notes the most important or interesting facts and advice, without attribution. If I get anything wrong, or if anyone needs to know who made a given statement, please call me at the office, 512/929-3992, so that I can correct or supply the information.

The conference was held March 14. Speakers were Peter Z. Adelstein (on standardization activities), Fred Layne (tape), John Van Bogart (tape storage), John Powers (tape restoration), Fynette Eaton (The Archives' Center for Electronic Records), Douglas Stinson (CD lifetimes), Barry Roginski (optical disk migration) and Chris Cain (backup tape).

The optical disk people are doing a good job of writing standards.... The Tape Head Interest Committee (THIC) is producing documents on the permanence of tape.

Tape binders are mainly polyurethane, which have evolved significantly, and are more lasting now. Tape pack is the most important factor in archivability.... Tape 456 is Quantegy Corporation's most permanent tape.... Archive the software and generational protocol with the tape.... Japanese competitors of American tape manufacturers are very secretive, which is an obstacle to cooperative formulation of standards.

"Sticky shed" syndrome is caused by breakdown of the binder. Ligamers migrate to the surface, the tape squeaks and stops. When this was discovered in 1986 or '87, a heat treatment was developed in a crash program: bake them at 125°F for eight hours, which recombines the ligamers. The effect lasts 30 days at most, but the treatment can be repeated at least 20 times. Before the ligamers break down again, copy the tape. [Note: Most specialists recommend against use of this method by untrained people.]

Oxide systems last longer than metal particles under adverse conditions.... Analog media probably last longer than digital.... In studies comparing different recording media, life expectancy needs to be qualified by temperature, RH, failure criteria, percent surviving, and confidence interval.... Until we have standards for magnetic tape, write specs into your purchase order; ask for the life expectancy of the product and how they calculate it.... Keep the environment clean and dustfree. Bit densities are getting higher, so smaller debris does more damage.... Store tails out to preserve a good tape pack. Rewinding periodically is not as important now that big reels aren't used as much.

In the LBJ Library, there is a wide variety of tape formats of varying quality. They have lots of spare parts, equipment and technicians. It took them six months to find a machine that would play a databelt. They finally got one on loan from IBM's museum.

Make sure your machine works before you put an old tape in it.... Know what's on the tape. The more descriptive information on the tape, the better. Transfer the data when you rerecord. A lot of the tapes in the LBJ Library are acetate, which is OK, but as soon as it starts to deteriorate, it goes rapidly. If you smell it, copy it. Store tapes with vinegar syndrome separately from the others.

In the 1970s, the LBJ Library had its obsolete tape copied, using a low-bid service company that copied them onto tapes that are now completely obsolete. Now the Library is doing things right, recording first on multiple DAT (digital audio tape) copies, then doing an analog master.

The National Archives' Center for Electronic Records has been in existence for 30 years.... The Archival Preservation System (APS) was formed with several goals in mind, including: to retain control of the media and do their own preservation, and to widen the choice of formats for receiving and sending records. They will get nine 586 Intel processors, to handle all formats.

Archival Electronic Records Inspection and Control (AERIC) was organized in 1992.


The Infoguard Protection System is Kodak's scratch-tolerant top coating for CD-ROMs. "This is the first archival storage system that's made money for anyone."

Only 1 to 3% of government records are retained forever. All media are accepted by the Archives. The holdings of the Archives are growing exponentially. In 1994, NARA started accepting CD-ROMs (data files) on a trial basis. Optical tape is new, and could be an archival medium; but there is no commercial product yet.

In 1991, the Archives issued the first guidelines for state and local governments on long-term access to electronic data. It emphasized that this was the users' responsibility, not the vendors', who say "Don't worry-we'll take care of that," and "This will save you money." A survey of state and local government records systems showed that many systems were proprietary. They were advised to put the software code in the bank.

NARA learned 13 lessons during a large conversion project (to get copies of the Bush tapes so as to make them available to the public). Some of the lessons were: Do not postpone conversion. Expect it to be resource-intensive. Upgrade system components at the same time. Select system components that meet standards. Get any available hardware or software ever used with the files. Clean up files before you convert. Perform routine backups as you convert.

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