Caddy (hardware)

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[edit] Hard disk drive caddy

A hard disc drive caddy is a sheath, typically plastic or metallic, within which a hard disc drive can be placed and connected with the same type of adapters as a conventional motherboard and power supply would use. The exterior of the caddy typically has two female sockets, used for data transfer and power.

A number of variants exist:

• Some larger caddies can support several devices at once and can feature either separate outputs to connect each device to a different computer, or a single output to connect both over the same data cable.
• Certain don't require a power supply, instead depending on the computer it is connected for power.
• Some caddies have integrated fans with which to keep the drives within at a cool temperature.
• caddies for all major standards exist, supporting for example ATA, SCSI and S-ATA drives and USB, SCSI and FireWire outputs.

Advantages:

• relatively high transfer speed; typically faster than other common portable media such as CDs, DVDs and USB flash drives, slower than drives connected using solely ATA, SCSI and S-ATA connectors
• storage; typically larger than CDs, DVDs and USB flash drives
• price-to-storage ratio; typically better than CDs, DVDs and USB flash drives

Disadvantages:

• power; most variants require a supply, unlike CDs, DVDs and USB flash drives
• size; typically larger than CDs, DVDs and USB flash drives

[edit] Optical media caddy

Some early CD-ROM drives used a mechanism where CDs had to be inserted into special cartridges or caddies, somewhat similar in appearance to a jewel case. Although the idea behind this—a tougher plastic shell to protect the disc from damage—was sound, it did not gain wide acceptance among disc manufacturers. Drives that used the caddy format required "bare" discs to be placed into a caddy before use, making them less convenient to use. Drives that worked this way were referred to as caddy drives or caddy load(ing), but from about 1994 most computer manufacturers moved to tray-loading[1], or slot-loading drives.

The same system is still available for more recent formats such as DVD-RAMs^{[citation needed]} but is not common.

The PlayStation Portable, UMD disk is a similar concept, using a small proprietary DVD-type disk, in a fixed unopenable caddie as both a copy protection and damage prevention measure.