Forward compatibility or upward compatibility is a design characteristic that allows a
system
A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...
to accept
input intended for a later
version
Version may refer to:
Computing
* Software version, a set of numbers that identify a unique evolution of a computer program
* VERSION (CONFIG.SYS directive), a configuration directive in FreeDOS
Music
* Cover version
* Dub version
* Remix
* ''V ...
of itself. The concept can be applied to entire systems, electrical
interface
Interface or interfacing may refer to:
Academic journals
* ''Interface'' (journal), by the Electrochemical Society
* '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics''
* '' Inter ...
s,
telecommunication
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...
signals
A signal is both the process and the result of Signal transmission, transmission of data over some transmission media, media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processin ...
,
data communication protocols,
file format
A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...
s, and
programming language
A programming language is a system of notation for writing computer programs.
Programming languages are described in terms of their Syntax (programming languages), syntax (form) and semantics (computer science), semantics (meaning), usually def ...
s. A
standard Standard may refer to:
Symbols
* Colours, standards and guidons, kinds of military signs
* Standard (emblem), a type of a large symbol or emblem used for identification
Norms, conventions or requirements
* Standard (metrology), an object ...
supports forward compatibility if a
product that complies with earlier versions can "
gracefully" process input designed for later versions of the standard, ignoring new parts which it does not understand.
The objective for forward compatible technology is for old devices to recognise when data has been generated for new devices.
Forward compatibility for the older system usually means
backward compatibility
In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with Input ...
for the new system, i.e. the ability to process data from the old system; the new system usually has ''full'' compatibility with the older one, by being able to both process and generate data in the format of the older system.
Forward compatibility is not the same as
extensibility
Extensibility is a software engineering and systems design principle that provides for future growth. Extensibility is a measure of the ability to extend a system and the level of effort required to implement the extension. Extensions can be t ...
. A forward compatible design can process at least some of the data from a future version of itself. An extensible design makes upgrading easy. An example of both design ideas can be found in web browsers. At any point in time, a current browser is forward compatible if it gracefully accepts a newer version of
HTML
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...
, whereas how easily the browser code can be upgraded to process the newer HTML determines how extensible it is.
Examples
Telecommunication standards
The introduction of
FM stereo
FM broadcasting is a method of radio broadcasting that uses frequency modulation (FM) of the radio broadcast carrier wave. Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to transmit high-fidelity sound ...
transmission, or color television, allowed forward compatibility, since monophonic FM radio receivers and black-and-white TV sets still could receive a signal from a new transmitter.
It also allowed backward compatibility since new receivers could receive monophonic or black-and-white signals generated by old transmitters.
Video gaming
* The
Game Boy
The is a handheld game console developed by Nintendo, launched in the Japanese home market on April 21, 1989, followed by North America later that year and other territories from 1990 onwards. Following the success of the Game & Watch single-ga ...
is able to play certain games released for the
Game Boy Color
The (GBC or CGB) is an 8-bit handheld game console developed by Nintendo. It was released in Japan on October 21, 1998, and to international markets that November. Compared to the original Game Boy, the Game Boy Color features a color TFT scre ...
. These games utilize the same cartridge design as games for the original Game Boy, though the plastic used is typically black rather than gray and feature the GBC's logo on the label and packaging;
Nintendo
is a Japanese Multinational corporation, multinational video game company headquartered in Kyoto. It develops, publishes, and releases both video games and video game consoles.
The history of Nintendo began when craftsman Fusajiro Yamauchi ...
officially referred to such titles as being "Dual Mode".
* The
Leapster is able to play Leapster L-Max games, and the Leapster L-Max is able to play
Leapster2 games.
* The original
PlayStation
is a video gaming brand owned and produced by Sony Interactive Entertainment (SIE), a division of Japanese conglomerate Sony. Its flagship products consists of a series of home video game consoles produced under the brand; it also consists ...
is compatible with the
DualShock 2
The DualShock (originally Dual Shock, trademarked as DUALSHOCK or DUAL SHOCK, with the PlayStation 5 version as DualSense) is a line of gamepads developed by Sony Interactive Entertainment (formerly Sony Computer Entertainment) for the PlayStat ...
controller. Likewise the
PlayStation 3
The PlayStation 3 (PS3) is a home video game console developed and marketed by Sony Computer Entertainment (SCE). It is the successor to the PlayStation 2, and both are part of the PlayStation brand of consoles. The PS3 was first released on ...
can be played with a
DualShock 4
The DualShock (originally Dual Shock, trademarked as DUALSHOCK or DUAL SHOCK, with the PlayStation 5 version as DualSense) is a line of gamepads developed by Sony Interactive Entertainment (formerly Sony Computer Entertainment) for the PlayStati ...
and
DualSense
The DualShock (originally Dual Shock, trademarked as DUALSHOCK or DUAL SHOCK, with the PlayStation 5 version as DualSense) is a line of gamepads developed by Sony Interactive Entertainment (formerly Sony Computer Entertainment) for the PlayStat ...
controller.
*The
Neo Geo Pocket
The Neo Geo Pocket series is a line of handheld game consoles developed and manufactured by SNK between 1998 and 2001. It began with the monochrome released in Japan on October 28, 1998 as SNK's first handheld system and a direct competitor to ...
was able to play most games from
Neo Geo Pocket Color
The Neo Geo Pocket series is a line of handheld game consoles developed and manufactured by SNK between 1998 and 2001. It began with the monochrome released in Japan on October 28, 1998 as SNK's first handheld system and a direct competitor to N ...
.
*The
WonderSwan
The is a handheld game console released in Japan by Bandai. Developed in collaboration with Gunpei Yokoi's company Koto Laboratory, it was the final piece of hardware Yokoi worked on before his death in 1997. Launched in March 1999 during the ...
is able to play some WonderSwan Color games.
*The
Xbox One
The Xbox One is a home video game console developed by Microsoft. Announced in May 2013, it is the successor to Xbox 360 and the third console in the Xbox#Consoles, Xbox series. It was first released in North America, parts of Europe, Austra ...
can use the controller from the
Xbox Series X
The Xbox Series X and Xbox Series S are the fourth generation of consoles in the Xbox series, succeeding the previous generation's Xbox One. Released on November 10, 2020, the higher-end Xbox Series X and lower-end Xbox Series S are part o ...
and
Xbox Series S, and likewise an Xbox One controller will work on the Xbox Series X and Series S.
*The
V.Smile Smartridge is compatible with every
VTech console and handheld game system. However, it does not support the
V.Smile Baby,
PC Pal, and
V.Flash systems. Depending on the device inserted, some functions may be limited, reflecting the varied capabilities of each console.
HTML
HTML
Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...
is designed to treat all tags in the same way (as inert, unstyled
inline elements) unless their appearance or behavior is overridden; either by the browser's default settings, or by scripts or styles included in the page. This makes most new features degrade gracefully in older browsers. One case where this did not work as intended was script and style blocks, whose contents are meant to be interpreted by the browser instead of being part of the page. Such cases were dealt with by enclosing the contents within comment blocks.
As there is no mandatory upgrade of computers or web browsers, many web developers use a
graceful degradation
Fault tolerance is the ability of a system to maintain proper operation despite failures or faults in one or more of its components. This capability is essential for high-availability, mission-critical, or even life-critical systems.
Fault to ...
or
progressive enhancement
Progressive enhancement is a strategy in web design that puts emphasis on web content first, allowing everyone to access the basic content and functionality of a web page, while users with additional browser features or faster Internet access r ...
approach, attempting to make newly-created websites that are usable by people who have turned off Javascript or who have old computers or old web browsers or on a slow connection, yet still taking advantage of faster hardware and better JavaScript support in more modern web browsers, when available.
Optical media
Each of the three most common 12 cm
optical media
An optical disc is a flat, usuallyNon-circular optical discs exist for fashion purposes; see shaped compact disc. disc-shaped object that stores information in the form of physical variations on its surface that can be read with the aid o ...
formats (
CD,
DVD
The DVD (common abbreviation for digital video disc or digital versatile disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any ki ...
, and
Blu-ray
Blu-ray (Blu-ray Disc or BD) is a digital optical disc data storage format designed to supersede the DVD format. It was invented and developed in 2005 and released worldwide on June 20, 2006, capable of storing several hours of high-defin ...
) was first released in read-only form years before writable forms were available. Within each format, there is both forward and backward compatibility, in that most older read-only drives and players can read (but not write) writable media in the same format, while read/write drives can read (but not write) old read-only media. There is no forward compatibility between formats; a CD player, for instance, can't read a DVD (a newer format), not even the audio tracks. There may be backward compatibility for better marketability (such as a DVD player playing an audio CD), but it is not intrinsic to the standards.
[
]
Not upwardly compatible
Some products are not designed to be forward compatible, which has been referred to as NUC (not upwardly compatible). In some cases this might be intentional by the designers as a form of
vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lockin, makes a customer dependent on a vendor for products, unable to use another vendor without substantial switching costs.
The use of open standards and alternati ...
or
software regression.
For example, a cubicle producer considers changing their cubicle design. One designer promotes changing the footprint from square to 1.2 meter square. Immediately, the sales manager calls "NUC" and the problem is understood: if the footprint changes and existing customers are considering buying more from the producer, they will have to fit a different sized unit in an office designed for the 4 foot square cubicle.
Planned obsolescence
In economics and industrial design, planned obsolescence (also called built-in obsolescence or premature obsolescence) is the concept of policies planning or designing a good (economics), product with an artificially limited Product lifetime, u ...
is a type of upward compatibility, but rather than adopting a policy of backwards compatibility, companies adopt a commercial policy of backwards incompatibility so that newer apps require newer devices.
See also
*
Backward compatibility
In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with Input ...
*
Bug compatibility
Computer hardware or software is said to be bug compatible if it exactly replicates an undesirable feature of a previous version. The phrase is found in the Jargon File.
An aspect of maintaining backward compatibility with an older system is tha ...
, backward compatibility that maintains the known flaws
*
Computer compatibility
A family of computer models is said to be compatible if certain software that runs on one of the models can also be run on all other models of the family. The computer models may differ in performance, reliability or some other characteristic. Th ...
*
Downcycling
Downcycling, or cascading, is the recycling of waste where the recycled material is of lower quality and functionality than the original material. Often, this is due to the accumulation of tramp elements in secondary metals, which may exclude th ...
*
Future proofing
*
Repurposing
Repurposing is the process by which an object with one use value is transformed or redeployed as an object with an alternative use value.
Description
Repurposing is as old as human civilization, with many contemporary scholars investigating ho ...
References
{{Reflist
External links
Rule of Extensibility: Design for the future, because it will be here sooner than you think in
The Art of Unix Programming
Backward compatibility
Interoperability