Tagged: tape

Open reel instrumentation and data logging tape (1949 – 2000s)

Magnetic tape was first used for data logging and instrumentation recording in 1949, when Jack Mullins installed modified Ampex Model 300s at Point Mugu Naval Air Station and at Edwards Air Force Base, both in southern California.

Tape has been heavily used since then for military, industrial, government and research applications. The Inter-Range Instrumentation Group (IRIG) set the standards for instrumentation tape recorders.

Instrumentation recorders were built to much more stringent standards than other tape recorders, and recorders that used direct, FM and PCM recording have been available.

On ¼-inch wide tape, there are typically 4 tracks, whereas on ½-inch tape there were 7, or sometimes even 14, tracks. On 1-inch tape, there were 14 or 28 tracks. Tape is usually wound on the reel with the recording surface facing towards the hub (the opposite of audio tape). Metal NAB reels were often used, for reels between 10.5 and 16-inches, but 7-inch plastic reels with cine spindle hubs have also been used.

Instrumentation recorders also used tape in cassette form, including systems that recorded onto S-VHS tape, and the Digital Instrumentation Recorder from Sony that used the SD1 cassette.

Instrumentation and data logging systems now use hard disks or flash memory for storage.

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Digital Data Storage (DDS) (1989 – 2007)

Digital Data Storage (DDS) was introduced in 1989, and used a version of Digital Audio Tape (DAT) for storing data.

DDS used helical scanning on magnetic tape, and stored between 1.3 GB in the first generation (DDS-1) and 36 GB uncompressed on the fifth generation (DAT 72) launched in 2003.

During its life, DDS competed against formats such as Linear Tape-Open (LTO), Advanced Intelligent Tape (AIT), VXA, and Travan, and over 18 million DDS drives were sold.

Generally, DDS drives can read and write to media of one or perhaps two previous generations only, so DDS-4 drives cannot read or write from DDS-1 tapes. DDS drives cannot read or write to media from later generations.

Two later generations (DDS-160 and DDS-320) both use 8mm wide tape in a slightly thicker cartridge, whereas the first five generation of DDS used 3.81 mm tape (often labelled as 4mm DDS).

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Preservation / Migration

media stability 3obsolescence 3Whilst DDS drives are still available secondhand, a single drive cannot read more than three generations of DDS.

The earliest tapes are now nearly 30 years old

 

DVCPRO (1995 – early 2010s)

DVCPRO (also known as DVCPRO25 or D-7) is a variation of the DV format, and was introduced by Panasonic in 1995 for professional and broadcast use.

In common with all DV formats, DVCPRO uses tape that is ¼-inch (6.35 mm) wide, but DVCPRO uses metal particle (MP) tape rather than metal evaporate. DVCPRO also adds an analogue audio cue track and a control track to make editing easier.

DVCPRO50 was introduced in 1997 and used two DV codecs in parallel, doubling the data rate over the original DVCPRO to 50 Mbps. DVCPRO50 decks can use DVCPRO tapes, but the tape is run at twice the speed so capacity is halved.

In 2000, Panasonic launched DVCPRO HD for high-definition recording. This had a data rate of 100 Mbps and competed with Sony’s HDCAM.

Panasonic stopped selling equipment using video tape around 2013.

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Metal tape Microcassette (1981 – mid-1980s)

The Microcassette was introduced in 1969 by Olympus for dictation purposes, but in 1981 and 1982 several devices were introduced that used the Microcassette for music recording and playback.

Several personal stereo devices, similar to the Sony Walkman were introduced, such as the Olympus SR-11, and there were also several Microcassette decks for Hi-Fi separates systems from brands such as JVC, Sanyo, Technics and Sony.

The Microcassette for music was a little different to the standard Microcassette and used metal tape (coated with pure metal particles rather than oxide) which had been introduced for the Compact Cassette in 1979 as this offered higher sound quality. Many of the new Microcassette music devices offered Dolby noise reduction, and of course this version of the Microcassette offered stereo sound.

A few pre-recorded tapes were released (mostly in Japan), but the format failed to take off and seems to have disappeared fairly quickly. Even at the time the tapes had limited availability and were expensive, and it’s now hard to find original metal tape Microcassettes.

Despite being used for music playback in its metal-tape form, the cassette seen in the 1971 film ‘A Clockwork Orange’ was the similar Mini-Cassette format and not a Microcassette.

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Grundig Stenorette (1954 – 1970s)

The Stenorette was an office dictation machine introduced by Grundig in 1954, and successfully sold internationally. It was perhaps the earliest magnetic tape dictation system – at the time of its introduction, most office dictation systems were using discs or belts onto which grooves were pressed, such as the SoundScriber, Audograph, or Dictabelt systems. The first model, the Stenorette A, was nicknamed the ‘tree frog’ due to its green colour. Like some other dictation systems, the microphone doubled as the speaker, and contained stop/start controls.

The Stenorette cassette contained a single reel of ¼-inch tape, and a loop on the end was pulled out and clipped into the take-up reel. Recording time was 30 minutes per cassette, but some offered 45 minutes. Some tapes, particularly those from the US, seem to have no cover and are simply a small reel.

The Stenorette cassette system lasted into the 1970s with the introduction of the Stenorette SL model in 1972, but Grundig launched its first machine using its new cassette format, the Steno-Cassette in the same year. The Steno-Cassette was a true cassette containing dual reels and as well as being more compact, didn’t need to be rewound before being removed from the machine. The Stenorette name was continued on machines using the newer Steno-Cassette format.

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DASH (Digital Audio Stationary Head) (1982 – mid-1990s)

Sony introduced the DASH (Digital Audio Stationary Head) in 1982 for use in professional recording studios. The DASH system could record two-channel audio on ¼-inch tape, or 24 or 48 tracks onto ½-inch tape, and DASH recorders were produced by Sony, Studer and TASCAM.

The tape itself looked identical to standard NAB open reel analogue tape, but tape for use in DASH and the competing (and incompatible) ProDigi format systems used metal-particle tape which was not suitable for use in analogue systems due to the faster wear on the heads. Several companies produced open reel metal-particle tape for digital audio systems, and some examples included 3M Scotch 275, Ampex 467, EMTEC 931 and Sony own-brand tape. Metal-particle tape was even more expensive than oxide-based tape for analogue systems.

Unlike some other digital audio recording systems using tape such as DAT or U-Matic which used helical scanning, the DASH and ProDigi systems used a stationary recording head.

The audio was encoded as PCM, and included error correction, and all DASH recorders were capable of using 16-bit resolution with a 44.1 or 48 kHz sampling rate, with a couple of models capable of 24-bit 48 kHz operation.

DASH and ProDigi were the two main open-reel digital audio recording systems in use from the early-1980s to the mid-1990s, but eventually the falling price of hard-disk space, as well as more compact systems such as ADAT, made them less viable.

Although DASH was a digital system, it still had the disadvantage of having to wind through the tape to find a particular point, and wear could still be a problem. Poorly maintained machines or tape, dust, or fingerprints could render tapes unusable despite the error correction system.

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Preservation / Migration

media stability 5obsolescence 5

EIAJ-2 (1972 – late 1970s)

EIAJ-2 was a video tape format developed by the Electronic Industries Association of Japan and sold by Matsushita under the National or Panasonic brands, and also by Hitachi. The format is also referred to as Omnivision. It was introduced around 1972, as Billboard magazine refers to it being under development in August 1972, and in February 1973, Panasonic re-emphasised its commitment to the format.

It was a development of the open reel EIAJ-1 standard and used the same ½-inch tape and recording specifications. However, the tape was enclosed in a cartridge to do away with the need for manually threading it, but unlike later video cassette formats the take-up reel is enclosed within the video recorder so the cartridge needed to be rewound before the cartridge could be removed from the machine.

EIAJ-2 offered colour recording on 30 minute cartridges (a 60 minute cartridge came later, and appears to be rare) and was used in the industrial, educational and consumer markets.

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media stability 5obsolescence 5

MII (1986 – early 1990s)

MII (pronounced as M 2) was an analogue videocassette format introduced by Panasonic in 1986 for professional use, to compete with Sony’s Betacam SP format.

MII was a development of the M format, which was originally derived from VHS, and it used ½ inch wide metal-formulated tape and component video recording.

Two sizes of MII cassette were available. The larger one was similar to a VHS cassette in size and had either a 60 or 90 minute recording time, and the smaller version provided 20 minutes.

MII had more success in the marketplace than its predecessor M, but MII suffered from poor marketing and customer support, and the machines gained a reputation for being less robust than those for Betacam SP.

It was used by a few UK television companies until the early 1990s, including Thames Television and TV-am. It was also used by NBC and PBS in the US, but NBC dropped it in the early 1990s in favour of the digital Sony D2 format.

The tape used in MII cassettes is very thin, and if stored badly can become mouldy and hence prone to tearing.

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Preservation / Migration

media stability 3obsolescence 5

Dictaphone Dictet (1957 – early 1960s)

The Dictaphone Dictet was a portable dictation device introduced by the Dictaphone Corporation in 1957. It was perhaps the earliest portable magnetic tape dictation system – the Grundig Stenorette was an office dictation system using tape, introduced in 1954. An earlier portable system, the Protona Minifon used wire recording.

The Dictet was fully transistorised and weighed 1.2kg. The cassette had a metal shell and could record up to 60 minutes (30 minutes per side) on ¼-inch tape that ran at 2½ inches per second. Using special mercury batteries, the Dictet could operate for 20 hours.

The Dictet lasted until at least 1962, but it is unclear how much longer it lasted against newer competitors such as the Compact Cassette of 1963.

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Philips EL 3581 (1958 – early 1960s)

The Philips EL 3851 was an office dictation machine introduced by Philips (known as Norelco in the US) in 1958 and was one of the earliest magnetic tape dictation systems (the Dictaphone Dictet was launched shortly before it). At the time of its introduction, most dictation systems were using discs or belts onto which grooves were pressed, such as the Dictabelt, SoundScriber and Audograph systems.

Although the EL 3851 uses a cartridge so no threading is required, the tape is housed on two separate 3-inch reels with ¼-inch tape and cine spindle holes suitable for domestic open reel tape recorders. Removing a clip from the cartridge shell allows the reels to be removed.

Like some other dictation machines, the microphone also doubles as a speaker, and contains some tape controls. A foot pedal and external speaker were also available.

Philips later introduced the much smaller Compact Cassette format in 1963, followed by the mini-cassette in 1967 and it doesn’t appear the EL 3851 was produced for long.

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