Hot swapping is the ability to remove and replace components of a machine, usually a computer, while it is operating. Once the appropriate software is installed on the computer, one can plug and unplug the device without rebooting. An example of this is the Universal Serial Bus (USB), that allows a user to add or remove peripheral devices such as a mouse, keyboard, or printer. It usually requires more sophisticated software and hardware than plug-and-play. In general, a things components are its parts; the things that compose it. ... A drawing of the everyday computer. ... Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. ... A BOOTING is any exercise of the verb to boot. ... Type A USB connector Dual images of the two Type B USB connectors, mini and full size, side and front view, compared with a U.S. 5¢ piece (nickel) in both images for scale. ... Plug and Play is a term used in the computer field to describe a computers ability to have new devices, normally peripherals, added to it without having to restart the computer. ...

Historically, only expensive systems have this ability as it is very difficult to engineer correctly.

Protocols that support hot swapping include PCMCIA, USB, FireWire, and SATA. Protocols that don't support hot swapping include IDE. Common hot-swappable devices include USB flash drives and some server hard drives. Others are PCMCIA cards (PC Cards) used for laptops and the Personal Media Drive available on some Hewlett-Packard machines (this has not been confirmed yet...) The PCMCIA is the Personal Computer Memory Card International Association, an industry trade association that creates standards for notebook computer peripheral devices. ... Type A USB connector Dual images of the two Type B USB connectors, mini and full size, side and front view, compared with a U.S. 5¢ piece (nickel) in both images for scale. ... A 6-Pin FireWire 400 connector FireWire (also known as i. ... A SATA power connector. ... ATA cables: 40 wire ribbon cable top, 80 wire ribbon cable bottom Advanced Technology Attachment (ATA) is a standard interface for connecting storage devices such as hard disks and CD-ROM drives inside personal computers. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... The Hewlett-Packard Company (NYSE: HPQ), commonly known as HP, is a very large, global company headquartered in Palo Alto, California, United States. ...

Hot swapping can also refer to the ability to alter the running code of a program without having to interrupt its execution, though few languages currently support it. Those that do include Lisp and Erlang. Lisp is a reflective, multi-paradigm programming language with a long history. ... Erlang is a general-purpose concurrent programming language and runtime system. ...

Machines that support hot swap need some ability to detect that a component has been removed. In addition all electrical and mechanical connections need to be designed such that neither the part nor the user can be harmed by removing it. Lastly, other parts in the system must be designed such that the removal of a different part does not harm operation. (Often there is some automatic recovery process.)

Simple implementations often require a component shut down procedure prior to removal. This simplifies implementation, but such devices are not robust in the case of part failure. Modern small computers often have USB and/or FireWire (also known as IEEE 1394 and iLink) buses that support this simple hot swap. If a device is removed while it is being used, the operations to that device fail and the user is responsible for retrying if necessary. As this action is normally done by end users this is not considered a problem. These hot swap operations are generally used either to move a peripheral from one computer to another, or to allow a device to synchronize data with a computer. A 6-Pin FireWire 400 connector FireWire (also known as i. ... For an account of the words periphery and peripheral as they are used in biology, sociology, politics, computer hardware, and other fields, see the periphery disambiguation page. ...

Complex implementations may recommend that the part be shut down, but there is sufficient redundancy in the system such that if a part is removed without being shutdown operation continues. In these systems hot swap is normally used for regular maintenance to the computer, or to replace a broken part. Redundancy, in general terms, refers to the quality or state of being redundant, that is: exceeding what is necessary or normal, containing an excess. ...

Additionally, there are two slightly differing meanings of the term hot swapping. In some contexts, it refers only to the ability to add or remove hardware without powering down the system, while in other contexts, it refers to the system's ability to autonomously detect when hardware is added or removed. In the former case, one can add or remove hardware without powering down, but the system software may have to be notified of the event in order to use the new hardware. Examples of the former include RS-232, FireWire and lower-end SCSI devices, while examples of the latter include USB, FireWire, PCI Express and higher-end SCSI devices. When comparing these two cases, it is common to only refer to the latter case as true hotplugging, and call the former case coldplugging. RS-232 (also referred to as EIA RS-232C or V.24) is a standard for serial binary data interchange between a DTE (Data terminal equipment) and a DCE (Data communication equipment). ... SCSI stands for Small Computer System Interface, and is a standard interface and command set for transferring data between devices on both internal and external computer buses. ... PCI Express (formerly known as 3GIO for 3rd Generation I/O, not to be mistaken with PCI-X) is an implementation of the PCI computer bus that uses existing PCI programming concepts and communications standards, but bases it on a much faster serial communications system. ... Coldplugging is often taken to mean the opposite of hotplugging. ...

See also

• Coldplug

Coldplugging is often taken to mean the opposite of hotplugging. ...

External links

• Hotplug support in Linux-based systems