Mini CDs are compact discs with a smaller form factor.

Formats

Amongst the various formats are the

CD single, an 80 mm disc. The format is mainly used for audio CD singles in certain regions (singles are sold on normal 120 mm CDs in many countries), much like the old vinyl single. An 80 mm disc can hold 21 minutes of music, or 180 MB of data. They are often referred to as Maxi CDs in some countries.
o The low density version holds 18 minutes, or 155 MB.
o An enhanced density version of the 80 mm disc holds 34 minutes, or 300 MB.

Business card CD, a truncated 80 mm disc with a storage capacity from 30MB to 100MB
 o The long axis is 80 mm while the short axis (from flat side to flat side) is generally between 58 and 68 mm
 o The disc may be rectangular with wings added on, to square off the rounded 80 mm disc.

60 mm disc, a round version of the business card, with the same capacity (50 MB)

When Mini CDs were first introduced in the United States, they were initially marketed as CD3, in reference to their approximate size in inches; larger CDs were called CD5, despite the fact that both CD specifications are defined solely in terms of metric units. These names failed to gain wide acceptance.

Compatibility

Most tray-loading CD devices have 2 'wells'; one sized for a normal CD, and a smaller, deeper well for MiniCDs to fit into.

Devices that feature an opening lid have no problem with MiniCDs, as the disc can simply be placed onto the spindle as with a normal CD.

Some vertically aligned tray-loading devices, such as the PlayStation 2 when placed vertically, require an adaptor for use with 80 mm CDs.

Slot-loading CD drives are generally incompatible, (the iMac of 1999 is an exception), but adapters are available that one can snap an 80 mm round miniCD into to extend the width to match that of a 120 mm CD, and thus work in many slot-loading devices. There are no adapters for business-card sized CDs.

Retail availability

As of 2005, many manufacturers are offering 80 mm CD-R and CD-RW discs for sale in retail electronics and office supply stores. These are sometimes marketed as 'Pocket CD-R/CD-RW' (Memorex) or 'Mini CD-R' (TDK). Most of the blank discs available in retail hold either 185MB (21 minutes) or 210MB (24 minutes) of data.

Business card CD-R media is available, usually in bulk quantities, through many Internet media warehouses. This media typically holds 50MB (6 minutes) of data or less.

While not technically 'mini' CD media, some CD manufacturing plants offer die-cut CD media. Most of these CD-R die-cut media styles actually have an 'embedded' mini CD recording surface, with the same capacity of that of a mini CD or business card CD.

Devices that use MiniCD

While almost any spindle-based or tray-based CD device can utilize mini CD media, some devices have been designed expressly to use the smaller format, usually for portability reasons.

Sony D-88

The first shirt-pocket CD player was the Sony D-88 (ca. 1990). It only played standard PCM audio (Red Book) CDs. It could play 120 mm discs if a guard was moved to allow the disc to protrude from the unit.

Memorex Mini CD MP3 Player

Later, Memorex offered a portable CD player that matched the formfactor for the 80 mm CD. The player was marketed as an MP3 device, and the user was encouraged to burn MP3 music files to a mini CD, and then play them in the player, which was noticeably smaller than a standard portable CD player. The player could also play Red Book audio content burned onto mini CD's. It can play both CD-R and CD-RW media, as well as pressed mini CD's.

Sony Mavica

Sony's Mavica line of digital cameras also offered some cameras that record directly to mini CD media. There were two models, the CD350 and the CD500, which offered 3.2 megapixels and 5.0 megapixels, respectively. These cameras could also record MPEG video directly to the Mini CD - a sort of precursor to mini DVD camcorders. Interestingly, the media size for these devices was quoted at 156MB, rather than 185MB. It is possible that these devices used a packet writing format which took away some available disk space for use by formatting information.

Imation RipGo

The Imation RipGo! was a portable CD-R burner that was a similar form factor to that of the Memorex Mini CD player. Again, it was marketed as an MP3 device, and it could play MP3 and WMA files burned onto Mini CD media. It was powered by an internal lithium ion battery that could power the unit for five hours of playback. The device suffered some setbacks, most notably a slow CD initialize time (the time during which the drive analyzes the contents of an MP3 CD), maximum of 4X burning speed (due to the device using USB 1.1 to connect to its host computer), and no support for CD-RW media. Some people have also reported issues using the device with 24 minute (210MB) mini CD media; the device was shipped with 21 minute (185MB) media and seemed unreliable when burning on the slightly higher density media.

Sony Photo Vault

Sony also manufactured a mini CD burning device, designed to be 'PC-free.' The device allowed the user to directly burn images from a Memory Stick or a USB flash drive or camera to a mini CD. It was a precursor to modern 'media vaults' such as the iPod photo adapters and various other hard disk based photo storage units.

Wikipedia information about Mini CD. This article is licensed under the GNU Free Documentation License . It uses material from the Wikipedia article 'Mini CD'