Tagged: cassette

Cassettes normally have two reels with a single span of magnetic tape. In some cases, the reels can be above each other.

Mohawk Midgetape (1955 – early 1960s)

The Mohawk Midgetape was an early portable tape recorder introduced by Mohawk Business Machines in 1955 with the Midgetape 44 model.

It used a tape cassette in a metal casing with ¼-inch tape allowing 30 or 45 minutes of recording on each side of the tape. The cassette design is unusual in having the spools on top of each other (coaxial).

The is no fast forward, and rewinding is done with a fold-out handle. It came with a microphone, and had a headphone jack. Accessories included a separate amplifier, an adaptor for recording telephone conversations, a wristwatch microphone, and a leather bag with hidden microphone.

Later models were fully transistorised (the 44 had used subminiature valve tubes) and the final Midgetape model was the 500 Professional introduced in 1959. There was a also a machine based on the Midgetape called the Lafayette Transcoder that in 1961 claimed to be able to record conversation up to 30 feet away.

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U-matic SP (1986 – late 1990s)

U-matic SP (Superior Performance) was a variant of the U-matic video cassette format, and was introduced by Sony in 1986. It used chrome tape and offered an improvement in performance over previous generations of U-matic (low-band and high-band) with a a horizontal resolution of 330 lines, a better signal to noise ratio, and Dolby C noise reduction.

Like previous generations of U-matic, the SP variant was analogue and used ¾-inch tape. SP tapes can be played on a standard U-matic deck, albeit with a loss in quality.

Two sizes of U-matic SP tape were available, with the smaller one aimed at the electronic news gathering market.

U-matic tape was replaced in broadcast applications by Sony’s own Betacam family of video cassette formats in the 1980s, and for other applications in the 1990s.

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S-VHS-C (1987 – early 2000s)

S-VHS-C (Super VHS Compact) was the compact version of S-VHS tape for use in analogue consumer camcorders.

It was introduced by JVC in 1987, and offered a horizontal resolution of about 400 lines over VHS-C‘s 240 lines, on tapes that could hold 30 or 45 minutes at standard speed.

The tapes could be placed in an adaptor and played back in an S-VHS deck, but it needed to be an S-VHS adaptor as the adaptor for VHS-C cassettes was differently notched to identify the tape as S-VHS. S-VHS-C tapes cannot be played back in a normal VHS machine even with an adaptor.

S-VHS-C competed with Hi8, which offered a comparable level of quality, but few S-VHS-C camcorder models were available.

No digital version was introduced (unlike full-size VHS with its D-VHS variant, and Hi8 with Digital8) and it was made obsolete by smaller digital formats like MiniDV, and eventually hard-drive recorders.

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SuperBeta (1985 – 1988)

SuperBeta (sometimes called High Band) was a development of the consumer Betamax video cassette format, and was introduced by Sony in 1985. A few other manufacturers also made SuperBeta machines, including NEC, Sanyo and Radio Shack.

SuperBeta increased the horizonal resolution from 240 to 290 lines (a big improvement, but still lower resolution than LaserDisc). In addition, some machines could record at a faster tape speed known as Beta-Is (4cm per second), the same speed as the original Beta-I mode on the first Betamax machines, for even higher quality.

Any Betamax tape could be used on a SuperBeta machine, but high quality tapes such as Sony’s PRO-X tapes were available to take full advantage of the SuperBeta’s higher quality in Super Beta Pro mode. Tapes recorded on a SuperBeta machine could be played without any problems in Beta Hi-Fi machines, but earlier Betamax VCRs showed some highlight streaking. No SuperBeta pre-recorded cassettes appear to have been released.

Shortly afterwards, JVC countered with the introduction of VHS HQ with a small increase in video quality, and in 1987 introduced the even higher-quality S-VHS.

By 1986, the market share of Betamax was down to 7.5% in the UK, and only one SuperBeta machine was marketed in the UK (the SL-HF950, which had the ‘linear skate’ cassette loading system). By 1988 Sony recognised the video format war was over and began producing VHS video recorders, marking the end of Betamax in the UK and Europe. However, Betamax still had it supporters and Sony continued to produce Betamax recorders in the US until 1993, and in Japan until 2002. In 2016, Sony ceased production of Betamax tapes.

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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

HDCAM SR (2003 – 2016)

HDCAM SR (Superior Resolution) was a professional high-definition digital video cassette format, introduced by Sony in 2003 as a higher quality variant of its existing HDCAM system.

Like other Betacam-related formats, HDCAM SR cassettes were available in large and small sizes, and had the same tape lengths as Digital Betacam (up to 40 minutes for S and 124 minutes for L tapes).

It used higher particle density tape allowing an increased bit rate (a choice or 440 or 880 Mbps). Like HDCAM, it was commonly used in high-definition television production.

Sony HDCAM SR tapes were black with a cyan lid and contained a 1K memory chip to store metadata about the tape.

In 2016, Sony announced that it was ceasing production of its remaining ½-inch video tape recorders and players, including those for the HDCAM SR format.

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D-VHS (1998 – 2007)

D-VHS was a later variant of VHS that recorded digitally, and was introduced in 1998. It was developed by the originator of VHS, JVC, along with Hitachi, Matsushita, and Philips.

D-VHS used MPEG recording, and could record in standard or high-definition.  There were several different recording speeds available, so a tape could have a variety of different capacities, for example a DF-300 tape that could hold 300 minutes at standard speed, could hold as much as 2100 minutes (35 hours) at LS7 (low speed, one seventh of the standard speed) if the machine was capable of using the very slowest speed. High-definition recordings reduced the capacity of the tape by half. Standard speed recordings had a higher bandwidth than DVD.

D-VHS tapes had a second hole on their underside that identified them to the recorder as being D-VHS tapes, and to record in D-VHS mode. Where the hole was missing, the machine would record in VHS or S-VHS format. VHS and S-VHS tapes could be played in the machine.

Unfortunately, sales of D-VHS recorders were poor, and so the price of them never fell greatly.

In 2002, a small number of pre-recorded D-VHS tapes were released under the D-Theater brand by four film-studios. However, despite being virtually identical to D-VHS, D-Theater tapes could only be played on D-VHS players with the D-Theater logo. D-Theater did provide much better video quality than DVD, at a time when high-definition formats such as Blu-Ray and HD-DVD were yet to be introduced.

The last D-Theater title was released in 2004, but D-VHS recorders were listed on the JVC website until 2007.

StorageTek 9840 (1998 – 2009)

The StorageTek 9840 was a magnetic tape system for data backup, primarily for mainframe use. The series was first introduced in 1998 with the T9840A, which had an uncompressed capacity of 20 GB. The final incarnation was the T9840D which had a capacity of 75 GB.

The StorageTek 9840 was unusual compared to its competitors such LTO and Super DLT, and to other StorageTek formats such the T10000, as the cartridges contained two reels, reducing the amount of tape that was stored in the cartridge but making loading of the tape very fast. Like many other backup tape cartridges, it used serpentine recording and ½-inch tape.

The T9840B doubled the data transfer rate of the T9840A model, making it the fastest tape drive at the time, though it was considered expensive compared to rivals, especially as its capacity was lower.

The final 9840 drives were shipped in 2009.

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DTRS (Digital Tape Recording System) / DA-88 (1993 – 2012)

DTRS (Digital Tape Recording System) was a magnetic tape format for professional digital audio recording. It was introduced by TASCAM in 1993 for use in the DA-88 digital multitrack recorder.

The DA-88 and later models could record up to eight tracks, but devices could be combined to record 16, 24 or more tracks. The first models in the range recorded at 16-bit resolution, with later models recording at 24-bit resolution. Sony also produced a DTRS recorder.

The tape itself was simply Hi8 video tape (an analogue video format) that was used to store audio in the digital DTRS format, and it allowed long continuous recording times. The format was considered to be affordable and reliable.

DTRS was discontinued in 2012, as recording studios have moved to hard-drive recording.

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Memocord (1965 – mid 1970s)

Memocord was a line of portable tape recorders for voice recording and dictation, introduced by the German Assmann company around 1965. The recorders and cassettes were produced in Austria by the Stuzzi company that had previously used the Memocord name for their own portable recorders using small open reels of tape.

The cassettes for the Assmann Memocord look a little like Compact Cassettes and consist of two reels in a clear housing so the amount of tape remaining can be seen. The cassettes protrude from the recorder, and this is so that on most (but not all models) they can be used to control the recorder; by pressing one end of the cassette, it plays, and by pressing the other end, the tape is rewound. This means most models of recorder only had one tape control button, and this is for recording. It also meant that there are some differences in shape between cassettes as the protruding end does not need to be the same.

Up to 90 minutes could be recorded onto a Memocord cassette.

There were several models of Assmann Memocord, and they appear to have been made until around the mid-1970s.

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