The Evolution Of Information Storage

Ages ago, men painted cryptic symbols on their hunting equipment. These symbols may have been directions to a specific area that yielded good provisions one season, or perhaps were indicative of social position in a nomadic tribe. Later, other men used chisels to set inscriptions into stone tablets. Many have been identified as merchant records, inventories, purchase and sale transactions, and even occasional personal remarks about the weather or local politics.

Paper was developed by the Chinese in A.D. 868 but didn't reach Europe until the middle of the 12th century. Parchment was first used by Eumenes II, King of Pergamum, in 1500 BC. The judges of Syracuse wrote the names of banished offenders on the leaves of olive trees in the first century BC. Paper, and its close relations, proved to be superior for ease of use, access, and storage capacity. Many pieces of paper could be stored in the place of just one stone tablet. Writing was much easier than inscribing in stone, and shuffling through a sheaf of papers shortened retrieval time.

The factor that was not considered was retention, and paper was not, and is not, the proper medium for long-term retention. Hence, information recorded on paper is nearly non-existent, with some notable exceptions. From the period of its development to about 600 years ago, we can't even be sure what information was documented in this way, since most of it is lost.

Microfilm was developed along with photography, and there are examples of microphotographed texts dating from 1852. The original use for microfilm occurred during the siege of Paris in 1870 when the Prussian Army cut off all communications to the city. Several hundred thousand messages were exchanged on microfilm by carrier pigeon, and many are still readable. This storage medium was finally applied to record keeping in the late 1920's.

Microfilm is basically the process of sealing silver halide grains into a thin gelatin layer on a clear backing. The backing itself has evolved to a stage where a polyester base claims a 500 year life expectancy rating, when stored properly. Microfilm has dominated information storage technology for some time, and is not likely to be replaced soon. Even the recently developed high density read-only memory (HD-ROM) is not human readable without an electron microscope, though it could come into wide use for storing very large amounts of information for very long periods of time.

The development of computers, and magnetic storage, was a major breakthrough. Saving to disk, or writing to tape, was much easier than filming each document, and retrieval time was greatly reduced with various search functions. But magnetic storage, on tape, hard drive or floppy disk, is so delicate a system that it might be described as ethereal. Although the federal government allows records to be stored on magnetic tape for up to 10 years with proper care, most long-time computer users realize just how easy it is to lose all your data for one reason or another, or for no obvious reason at all.

Optical Imaging
The next major storage device was optical imaging. Many people view optical technology as something entirely new, rather than the next step in the evolution of storage, and many of those same people have entrusted their most valuable information to optical storage. Some have made optical the record copy, and some have even made it their only copy.

Optical technology became a commercial enterprise in 1982. It was said to last indefinitely and to finally replace microfilm. Vendors touted it as the information and storage device of the future, and many concerns bought into the marketing concept. The unfortunate truth is that optical storage has a relatively short life expectancy – one that is not fully defined due to its short period of use and which may soon be obsolete.

Digital Video Disc
Digital Video Discs (DVD) were recently introduced at a Consumer Electronics Show in Las Vegas. The most significant thing about DVD is its storage capacity. It is reported to hold between 4.7 gigabytes and 17 gigabytes per disc, and the same disc can be used for movies, computer programs and audio discs and, yes, your VCR, CD drive and CD player are on their way to becoming antiquated.

Ann Balough has worked in records management since 1976, first for the US Army as a civilian records manager and, after receiving her master's degree in business in 1985, as a consultant. In 1990 she began writing and editing for the Records and Retrieval Report produced by Greenwood Press. "Yes, DVD is coming," Ann wrote me by e-mail recently, "The problem with CD is that it is not large enough to hold movies. So the entertainment industry began developing a new standard. The computer industry also wanted a way to increase CD capacity. For a time, they were looking at two new formats. Fortunately, they compromised. The new agreed-on standard is DVD. Consumer products for movies are already being shown this month....The initial capacity is 4.7GB per side on a 2-sided disk. There is a defined growth path, leading to about 18 GB. "Rewritable DVD (DVD-RAM) standards have been drafted. Expected capacity is between 2.6 and 3 GB per side. Most likely DVD will 'stack' transparent disks to achieve extra capacity. In this way, extra capacity can be achieved using current laser technology. "The good news is that all the specifications call for backward reading compatibility with current standards. Additionally, the new DVD computer disks will read the ISO 9660 format (the one most CDs use) or the new universal disk format (UDF). UDF is an effort to make data transportable across media from different computer platforms. The goal is to allow any disk to be read by any drive. "The bad news is that the current drives will be replaced. Any disks that do not adhere strictly to standards could be unreadable. You don't need to quit using CD-ROM technology, but you do need to plan for the end of it. Most experts believe that the lifespan of current CDS is limited. There is a great deal of work on blue lasers. When that comes to fruition (which is likely because so many are spending so much on it), capacity increases will be tremendous. Backward compatibility would require putting two lasers in one drive. This is unlikely to happen for many technical reasons. Also, the format of CD disks (they are written in one continuous spiral) puts an inherent limitation on access speed. So when the move to blue lasers comes, there will be a lot of pressure to move to a more random access method. "So, if you are planning to keep, and access, records on CD for more than five years, I recommend you do the following: Be absolutely sure you are recording to ISO 9660 standards. When it is possible to convert to UDF, do so. Plan to maintain the proper software and hardware to allow access to your CDS."

The Future
In the popular science fiction series Star Trek, information storage is achieved with the use of small, crystalline cubes. This is not as farfetched as it sounds, since successful work has already been done on storing information in crystals.

One of the questions we need to ask ourselves as records managers is: What format will my most important data be stored on 20, 50 or 100 years from now? Will it be easily accessible? Will it be intact? And will this data need to go through many conversion projects because I've recommended a storage device that, like optical imaging, will change every few years?

Devices for information storage will continue to evolve as time goes by. It's our job now to do our best to second guess storage evolution and preserve the information we are charged with retaining for the long haul.

Doug Johnson