DATs don't have good storage life and are pretty much the opposite of everything that an archival medium should be. Their design involves recording and playback via physical contact with the medium, plus data being recorded onto them at extremely high areal density which is compensated by the use of powerful error correction.
While DATs are being played back, error corrections are being applied at a considerably higher rate than, for example, with recordable CDs. This approach holds up OK as long as the tape keeps its physical integrity. But over time, and with temperature variations in storage, the physical tape warps and the oxide layer breaks down. The error correction rate then increases until it reaches the limit of its capacity. Beyond that the player is forced to interpolate samples or mute the signal (briefly and inaudibly at first but then for longer and longer intervals) whenever it encounters an area of the tape surface in which it can no longer read either the original data nor the (interleaved) error correction data.
This is also a problem with the older "pseudo-video" digital audio recorders such as the Sony PCM-F1 and even the professional PCM-1600 series which recorded on professional 3/4" U-Matic video tapes. I have several shelves of these old tapes and of DATs that I recorded in the 1980s and 90s. They're usually fine for a few years, and in theory one could preserve them by recopying them (digitally, during which error correction is applied and the data stream is renewed) but the tapes become "gappy" after a number of years and eventually the data becomes unrecoverable. So if you don't recopy your entire library every, say, three or four years, you will lose it all in 10 or 20 years, and any accidents in handling can cost you a valued recording.
CD-R (either audio, or better yet from an error correction standpoint, data recordings of uncompressed wave audio files) and DVD-R are much better choices for long storage life, particularly if you make multiple copies. Or if you want to use the recopying approach, dedicated hard drives give better value for the dollar spent, and it takes far less time to spin up a drive, recopy its contents and verify the results every few years. Of course the signal format for hard drives changes every few years, so you have to guess which types of drives will be readable in the future; SATA wasn't around years ago, and years from now will be replaced by something else that may well be incompatible, etc.
--best regards
Topic: DAT Tapes (Read 4930 times)