HP 82176A Mini Data Cassette (1982 – mid 1980s)

The 82176A Mini Data Cassette was introduced by Hewlett-Packard in 1982 for use in its 82161A mini-cassette tape drive that was designed for use with the HP 41 calculator.

The drive could be mains or battery powered for portable use. Tape speed was 30 inches per second, and each tape had a capacity of around 130 KB.

The 82161A mini-cassette tape drive was later used with the 71, 75 and some other models that used the HP-IL (Hewlett-Packard Interface Loop) interface.

The 82176A Mini Data Cassette looks almost identical to the Philips-designed Mini-cassette, but there are some differences in the shell, such as the tape openings and a notch on the top, that prevent a standard Mini-cassette being used in the HP tape drive.

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Gold CD-R (1996 – )

Gold CD-Rs (sometimes called archival CD-Rs) are intended to have a much longer life than standard CD-Rs. The main difference is that these CD-Rs use gold as the reflective layer to prevent oxidation (also known as laser rot), and they generally also use higher-quality dyes (preferably phthalocyanine). Being write-once also means the data cannot be accidentally overwritten.

Gold CD-Rs were introduced by MAM-A (Mitsui Advanced Media – America) around 1996.

Some gold CD-Rs suggest that they can offer data storage for to 300 years. Unfortunately there is no way to tell if this will be the case, and the future obsolescence of optical drives means they still should not be relied upon for long-term data storage.

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Preservation / Migration

DTS 5.1 Music Disc (1997 – early 2000s)

The DTS 5.1 Music Disc was a Compact Disc format offering surround sound audio, usually in the 5.1 configuration. The discs conformed to Red Book standard, so could be played in a standard CD player, but without the use of a DTS decoder all that would be heard is white noise. The potential confusion between DTS 5.1 Music Discs and standard Compact Discs meant some retailers were reluctant to stock them. There is some compression applied to the audio, so sound quality is arguably slightly lower than a standard CD.

Formats such as DVD-Audio and Super Audio CD, launched a few years later, could also offer surround sound and meant an end to the DTS 5.1 Music Disc, though several hundred titles were released on the format.

DTS surround sound technology is also used in movie theatres, on DVD-Video and on Blu-ray. It was also used on a small number of LaserDiscs.

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QSound Compact Disc (1991 – 2001)

QSound is an audio processing system introduced by QSound Labs. It was applied at the sound mixing stage and attempts to produce a surround sound effect from a stereophonic source. It was used on around 65 Compact Disc albums from 1991 to around 2001, which display the QSound logo. The first album to use QSound was Madonna’s ‘The Immaculate Collection’ and all the tracks were either re-mixed or mixed using the system.

No additional equipment was necessary to play a QSound Compact Disc, and the discs comply fully with Red Book standards.

As well as Compact Disc albums, the QSound technology was also applied to computer game audio, television programmes and film soundtracks.

On mono devices, music mixed using the QSound system can have elements missing.

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Fujifilm PhotoDisc CD-R (2004 – )

Launched in 2004, The Fujifilm PhotoDisc CD-R is essentially a standard CD-R disc with a black substrate layer that claims to protect the data from ultra-violet and solar radiation. It also uses a different dye (phthalocyanine rather than the usual cyanine) in the recording layer, which should offer more resistance to heat and sunlight.

Although they are reported to be very reliable, for archival purposes gold archival CD-R discs are probably better.

Despite the name, the discs can be used for any purpose that a standard CD-R can be used for, and don’t just store photos.

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MovieCD (1997 – late 1990s)

MovieCD was a CD-ROM format for video, introduced by Sirius Publishing Inc. in early 1997, that allowed people to view full-length movies on their Windows PC or laptop using a standard CD-ROM drive.

MovieCDs could be played on PCs running Windows 3.1 and Windows 95 without the need for any additional hardware or software, and the PC hardware requirements were fairly modest. The necessary software and the MotionPixels codec were on the discs themselves and installed automatically.

Each disc could hold up to 45 minutes of video, so two or sometimes three discs were necessary for longer films. The resolution was 320×236 pixels, and the format promised ‘near-TV quality’ images (though of course, the format could only be played on a PC – there were no set-top MovieCD players available).

Over 100 titles were available on the MovieCD format including anime, music concerts and feature films. It competed with Video CD and the newly launched DVD-Video, and no version of MovieCD was developed for versions of Windows beyond Windows 95. It was not a commercial success and disappeared after a few years.

Using the discs on a post-Windows 98 system can cause problems with other video and audio software.

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UHQCD (Ultimate High Quality Compact Disc) (2015 – )

UHQCD is a type of audio Compact Disc introduced by Memory-Tech in Japan in 2015, and is a development of the HQCD (High Quality Compact Disc) introduced six years previously. UHQCD discs conform to Red Book standards and are playable in any audio CD player. They don’t contain any more audio information than a standard CD, but it is claimed that a higher-quality manufacturing process and higher quality materials in the reflective layer produces higher precision audio reproduction.

A photopolymer is used instead of standard polycarbonate, since in their liquid state photopolymers achieve better replication of the pits on the CD stamper.

As of 2017, there were over 900 titles available on UHQCD.

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Blu-spec CD (2008 – )

The Blu-spec CD was introduced in 2008 by Sony, and is a Red Book-compliant audio Compact Disc, so is playable on all audio Compact Disc players. Sony launched with 60 titles on Blu-spec CD.

Its name is derived from the shorter-wavelength blue laser used to create the master copy, which is claimed to produced more precise pits to reduce distortion due to reading errors, along with a new polymer polycarbonate developed for the Blu-ray Disc.

In 2012, a newer version called Blu-spec CD2 (or BSCD2) was introduced that claimed to have a more precise cutting machine and master discs made from silicon wafers. Sony called it Phase Transition Mastering.

Due to existing limitations of Compact Disc Digital Audio, it is debatable whether Blu-spec CDs offer better sound quality as there is no extra information stored on the disc.

As of 2017, new titles are still being released on both formats.

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Yamaha Music Cartridge (1995 – late 1990s)

Yamaha introduced Music Cartridges in 1995 for use in some of its PSR range of entry-level and mid-range keyboards. These are not to be confused with an earlier Music Cartridge format from Yamaha that was used on its TYU-30 model in 1986.

The Yamaha Music Cartridge for PSR models were ROM cartridges containing either fully-arranged songs, or additional styles to add to the keyboard’s library, and were inserted into a slot on top of the keyboard. Six models of keyboard were able to accept Music Cartridges – PSR-320, PSR-420, PSR-520 and PSR-620, launched in 1995, and the PSR-330 and PSR-530, launched in 1997.

Later models of Yamaha keyboard used 3.5-inch floppy disks.

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5.25-inch ‘flippy’ disk (1976 – mid 1980s)

Flippy disk was a nickname given to single-sided floppy disks that had a second write-enabled notch cut into the sleeve so that the second side could be written to by a single-sided disk drive. Generally, these were 5.25-inch minifloppy disks, but 8-inch floppy disks could be modified in the same way, and this was possible because most of the openings on the sleeve of the disk were duplicated on both sides. It was a way of doubling the capacity of a floppy disk at a time when disks were expensive, although of course they had to be removed from the drive and turned over to access the extra capacity.

When the 5.25-inch minifloppy disk was introduced in 1976, all drives were single-sided. Double-sided drives were introduced in 1978, but suffered from early reliability problems. It wasn’t until 1982 that double-sided drives were supported by IBM PC-DOS in version 1.1. Drives such as Apple’s Disk II and the Commodore 1541 remained single-sided.

The second write-enabled notch could be made by hand, or special ‘disk doubler’ rectangular hold puncher could be bought to do the job. Flippy disks were also sold ready-made, and software was distributed on flippy disks that might have different programs on each side, or the same program but for different operating systems. Flippy disks sold for use in double-sided drives needed to have two index holes on either side of the hub hole.

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