Editing Hot swapping (section)

==Applications==
{{Expand section|date=April 2022|small=no|with=Major uses including server components and USB peripherals (currently mentioned in lead but not discussed in body). Other uses (not currently mentioned but shouldn't be hard to find reliable sources) include [[uninterruptible power supply]] batteries, electric car batteries.}}

=== Radio transmitters ===
Modern day [[radio transmitter]]s (and some [[TV transmitter]]s as well) use high power RF transistor power modules instead of [[vacuum tube]]s. Hot swapping power modules is not a new technology, as many of the radio transmitters manufactured in the 1930s were capable of having power tubes swapped out while the transmitter was running—but this feature was not universally adopted due to the introduction of more reliable high power tubes.

In the mid-1990s, several radio transmitter manufactures in the US started offering swappable high power RF transistor modules.
* There was no industry standard for the design of the swappable power modules at the time.
* Early module designs had only limited patent restrictions.
* By the early 2000s, many transmitter models were available that used many different kinds of power modules.

The reintroduction of power modules has been good for the radio transmitter industry, as it has fostered innovation. Modular transmitters have proven to be more reliable than tube transmitters, when the transmitter is properly chosen for the conditions at the transmitting site.

Power limitations:
* Lowest power modular transmitter: generally 1.0&nbsp;kW, using 600&nbsp;W modules.
* Highest power modular transmitter: 1.0&nbsp;MW (for [[Longwave|LW]], [[Mediumwave|MW]]).
* Highest power modular transmitter: 45&nbsp;kW (FM, TV).

===Gaming===
Although most contemporary [[video game]] systems can interchange games and multimedia (e.g. [[Blu-ray]]s) without powering down the system, older generations of systems varied in their support of hot-swapping capabilities. For example, whereas the Sony PlayStation and PlayStation 2 could eject a game disc with the system powered on, the Nintendo Game Boy Advance and the Nintendo 64 would freeze up and could potentially become corrupt if the game cartridge was removed with the power on. Manufacturers specifically warned against such practices in the owner's manual or on the game cartridge.<ref name="Health & Safety Precautions for Cartridge-Based Consoles">{{cite web|url=https://www.nintendo.com/consumer/manuals/precautions_console_pak_english.jsp|publisher=[[Nintendo]]|title=Health & Safety Precautions for Cartridge-Based Consoles|website=nintendo.com|access-date=2014-04-22}}</ref> It was supposedly for this reason that [[Stop 'N' Swop]] was taken out of the [[Banjo-Kazooie|Banjo-Kazooie series]] and ''[[Donkey Kong 64]]''. With the [[Sega Genesis|Sega Genesis/Mega Drive]] system, it was sometimes possible to apply [[Cheating in video games|cheats]] (such as a player having infinite lives) and other temporary software alterations to games by hot swapping cartridges, even though the cartridges were not designed to be hot swappable.<ref>{{cite book |title=Sega Genesis Games Secrets Greatest Tips |edition=2nd |publisher=[[Prima Publishing]] |year=1994 |page=217 |url=https://books.google.com/books?id=jjmZAmgTRWIC |author=The editors of [[GamePro|GamePro magazine]] |access-date=2014-05-12|isbn=9781559584012 }}</ref>

=== Keyboards ===
{{See also|Keyboard technology}}Hot-swappable keyboards enable changing the [[List of keyboard switches|switches]] without having to disassemble the keyboard.<ref name=":02">{{Cite web |date=2022-09-15 |title=What are hot-swappable keyboard switches? |url=https://www.digitaltrends.com/computing/what-are-hot-swappable-switches/ |access-date=2022-12-02 |website=Digital Trends |language=en}}</ref> On standard mechanical-switch keyboards, the switch is directly [[Solder|soldered]] to the [[Printed circuit board|PCB]]. Hot-swappable keyboards instead have a socket in its place that allows the switch to be freely replaced without re-soldering.<ref>{{Cite web |title=The 8 Best Hot Swappable Mechanical Keyboards – Review Geek |url=https://www.reviewgeek.com/34512/the-4-best-hot-swappable-mechanical-keyboards/ |access-date=2022-12-02 |website=www.reviewgeek.com |date=9 February 2020 |language=en-US}}</ref>

Due to hot-swappable keyboards being less common, they often require being custom built or bought from custom keyboard manufacturers.<ref name=":02" /> They can be found in a variety of sizes and [[Keyboard layout|layouts]], including more specialized [[Ergonomic keyboard|ergonomic]] layouts.

=== Software development ===
{{Further information|Dynamic software updating|Interactive programming}}

Hot swapping can also refer to the ability to alter the running code of a program without needing to interrupt its execution. [[Interactive programming]] is a [[programming paradigm]] that makes extensive use of hot swapping, so the programming activity becomes part of the program flow itself.

Only a few [[programming language]]s support hot swapping natively, including [[Pike (programming language)|Pike]], [[Lisp (programming language)|Lisp]], [[Erlang (programming language)|Erlang]], [[Smalltalk]], Visual Basic 6 (not [[VB.NET]]), [[Java (programming language)|Java]] and most recently [[Elm (programming language)|Elm]]<ref>{{cite web|url = http://elm-lang.org/blog/Interactive-Programming.elm|title = Interactive programming – Hot-swapping in Elm|publisher = elm-lang.org|access-date = 2015-02-15|archive-date = 2013-10-06|archive-url = https://web.archive.org/web/20131006235603/http://elm-lang.org/blog/Interactive-Programming.elm|url-status = dead}}</ref> and [[Elixir (programming language)|Elixir]]. [[Microsoft Visual Studio]] supports a kind of hot swapping called Edit and Continue, which is supported by [[C Sharp (programming language)|C#]], VB.NET and [[C (programming language)|C]]/[[C++]] when running under a debugger.<ref>{{cite web|url=http://msdn.microsoft.com/en-us/library/bcew296c(VS.80).aspx|title=MSDN Article for Edit and Continue|publisher=Msdn.microsoft.com|access-date=2013-08-18|archive-date=2010-07-31|archive-url=https://web.archive.org/web/20100731042922/http://msdn.microsoft.com/en-us/library/bcew296c(VS.80).aspx|url-status=dead}}</ref>

Hot swapping is the central method in [[live coding]], where programming is an integral part of the runtime process. In general, all programming languages used in live coding, such as [[SuperCollider]], [[TidalCycles]], or [[Extempore_(software)|Extempore]] support hot swapping.

Some web-based frameworks, such as [[Django (Web framework)|Django]], support detecting module changes and reloading them on the fly.  However, although the same as hotswapping for most intents and purposes, this is technically just a [[cache (computing)|cache]] purge, triggered by a new file. This does not apply to markup and programming languages such as [[HTML]] and [[PHP]] respectively, in the general case, as these files are normally reinterpreted on each use by default.  There are a few [[Content management system|CMSes]] and other PHP-based frameworks (such as [[Drupal]]) that employ caching, however.  In these cases, similar abilities and exceptions apply.

Hot swapping also facilitates developing systems where large amounts of data are being processed, as in entire genomes in bioinformatics algorithms.<ref>{{cite journal | title = HotSwap for bioinformatics: A STRAP tutorial| year = 2006|publisher=Biomedcentral.com| doi = 10.1186/1471-2105-7-64| last1 = Gille| first1 = Christoph| last2 = Robinson| first2 = Peter N.| journal = BMC Bioinformatics| volume = 7| page = 64| pmid = 16469097| s2cid = 18283272| pmc = 1386713| doi-access = free}}</ref>