History (1988): DAT Tomorrow’s Streamer?

It won’t be the first time that audio/video industry products have led to computer hardware.

Magnetic audio tape recorders generated a lot of computer peripherals, from the first cassette drives, including various types of magnetic tape units, up to the IBM 3480’s cartridges.

Digital optical discs have been originated in the videodisc technology. CD-ROM is directly derived from the audio CD. Some streamers are using video cassettes.

The latest top product in the world of sound recording, is the DAT (Digital Audio Tape). Though this brand-new product is hardly marketed in Western countries, the first international big maneuvers have already started to adapt DAT, as a mass storage device for data processing applications.

But, what is DAT exactly? The standard black vinyl disc is a pure analogue recording support, and the continuous rubbing of the diamond stylus is detrimental to this support. On CD’s, on the contrary, the audio signal has been digitized and the related digital information is read by a laser head. The public is generally following these new technologies. But there is no way for you to record a CD at home, since it has to be pressed in factory.

Some months ago, the idea of DAT came from Japan. The audio signal is still digitized, coded on a helical scan recording magnetic tape, like on VCR VHS or 8mm video camera tapes. Thanks to error correction systems (such as Reed Solomon code, well-known in the data processing industry), the perfect quality of sound is again obtained, the same as for CD’s. Moreover, you can record and erase at home, as much as you wish. But most of musical editors are trying to stop DAT systems flooding by every possible means, since these tape recorders allow anyone to get an almost perfect copy without any possibility to recover the royalties attached to the copyright. This full braking effort is obviously delaying the marketing of DAT tape recorders, already on current sale in Japan and the Western world.

The change over from audio DAT to data processing DAT (Data-DAT) is a plain conclusion that could upset a large part of the streamer market. While audio DAT uses a digital recording process, why not come out with Data-DAT, a peripheral computer, with this technology?

Hewlett Packard and Sony, already partners for 3.5-inch disks, came to an agreement for developing a series of mass storage units, based on this Data DAT (Exabyte and Hitachi also work this way). The first evaluation machines should appear in Great Britain (Bristol, HP) and Japan (Sony) at the beginning of this year, first deliveries are being promised for the end of the year with a first standard 5.25-inch disk full-height unit drive.

But the size should reduce afterwards: at the last Berlin Fair, Sony announced the first portable digital audio tape recorder (1.8kg nevertheless ). Matsushita Electric comes to a 210x40x122mm size and a 1,080g weight without batteries (1,450g with).

What does this new streamer have more than those actually selling on the market? Two times smaller (75x54x10.5mm), the 60m tape DAT cartridge (allowing 120mn music recording) will be able to memorize about 1.2GB, 6 to 20 times more, depending on the circumstances, than actual units of backup cartridges, twice as much than a read-only CD-ROM. The transfer rate, about 170KB/s, will double, with an average 20s access time, taking from a few milliseconds to 40 seconds to unwind the whole 3.81mm large and 13 microns thick digital tape.

Its superior specifications come from the recording process and the nature of its magnetic support. It’s made of a metal particule layer that gives a better density and accelerates the transformation flux of the magnetic field. The helical recording process is the same as on the video recorders, with parallel tracks sideways on the tape. Instead of DAT, you sometimes hear about R-DAT (for Rotary head system-Digital Audio Tape), compared to S-DAT (Stationery head system-DAT).

“It would take 2 or 3 more years to come out with comparable products with other technologies,” says Peter Bramhall, HP’s project manager in R&D division in Bristol, when interviewed.

And, above all there is no technical risk since this product is already available. Available it must be when you see the Japanese excitement for this audio DAT. They’re all there. Just name a big Japanese electronic firm and you can’t be mistaken. We found Aiwa, Akai, Clarion, Hitachi, JVC, Kenwood, Matsushita, Mitsubishi, Onkyo, DAT Pioneer, Sharp, Sansui, Sony and Toshiba. They have or will soon have audio recorders, Hitachi Maxwell, Matsushita, Sony TDK and Taiyo Yuden are getting ready to produce thousand miles of tapes. Philips Grunding, in Europe, made recent announcements for the machines, BASF and Bayer for the media, probably Ortofon International (Denmark) for both, under Japanese license. All these people, more or less involved in computers, will easily change to Data-DAT. There is a committee, the DAT Conference, convening no less than 85 different companies.

The worldwide big production machine that’s beginning to set up with the audio DAT is going to advantage computer streamers.

How much is a 1.2GB streamer going to cost? HP and Sony won’t say a word. But you can come close looking at the price of an audio DAT, similar to the coming Data-DAT. In Japan, the recorder costs from $ 1,100 to $ 1,300 including A/D and D/A converters (in October 19877, Sony announced its DTC-1000ES in West Germany for DM3,500).

Prices will probably drop under $1,000, with the competition and the a mount of production (Matsushita plans an annual output of 220,000 units in 1988 and 1.1 million in 1990, which isn’t exaggerated, when you know that Japan alone exports 500,000 audio CDs, a month!).

The DAT shouldn’t cost more than an actual and slower 240MB tape streamer. The same 60m tape for audio sells in Japan for $10-15 (Sony DT 120 sells for DM26 in Western Germany).

Since musical editors are slowing down on DAT publishing and DAT anti-copying device fail National Bureau of Standards tests, the manufacturers are going to have to turn to this new large potential market: data processing.

Data-DAT ought to shake up industries of tape, cartridge, including optical digital discs for mini and micro computers.

For applications, HP and Sony are also thinking of archiving and on-line inquiry even if access time is slow, and, for the moment, there’s no standard on this subject.

This single DAT cartridge, equivalent to 1,500 3.5-inch double-face double-density FDs, should enlarge the possibilities of data processing, always needing more and more memory for data and digitized image storage.

In the deep changing affecting all the storage peripherals, the next big client, after Data-DAT, will probably be the magneto-optical disk, a write-many read-many laser disk. Once more, this new medium, initially developed for audio and video, could be recovered by data processing.

Hitachi’s Data-Mass storage systems preliminary specs (november 1987):

Cassette specs:

• 76,250 FCI at 1,869tpi
• Maximum formatted capacity: 383MB on 23-meter tape length, 500MB on 30 meters, 75MB on 45 meters, 1TB on 60 meters.
• Tape width: 3.81mm
• Effective recording width: 2,613mm
• Tape speed: 8.15mm/s
• Track length: 23,501mm

Drive specs:

• Drive type: external
• Average access time: 20s
• Data transfer rate:
  • Sustained: 133KB/s (user data)
  • Peak: 1.5M/s (asynchronous)
• Interface: SCSI (ANSI X3.131)
• Buffer size: 128KB X3
• Error rate : <10-¹⁵
• Tape pass: >1,000 pass
• Helical scan/Azimuth recording
• Drum speed: 2,000rpm
• Price: Hitachi is looking at a price of ¥500,000 for a system comprising a DAT recorder, controller and interface.

This article is an abstract of news published on the former paper version of Data Storage Newsletter on issue ≠1, volume ≠1, on February 1988.