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Medium format

Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the 24 x used in 35 mm photography (though not including 127 sizes), but smaller than 4 x (which is considered large format photography).

In digital photography, medium format refers either to cameras adapted from medium-format film photography uses or to cameras making use of sensors larger than that of a 35 mm film frame. Some of the benefits of using medium-format digital cameras include higher resolution sensors, better low-light capabilities compared to a traditional 35mm DSLR, and a wider dynamic range.

Characteristics
Medium-format cameras made since the 1950s are generally less automated than smaller cameras made at the same time. For example, autofocus became available in consumer 35 mm cameras in 1977, but did not reach medium format until the late 1990s, and has never been available in a consumer large format camera.

The main benefit of medium-format photography is that, because of the larger size of the film or digital sensor (two to six times larger than 35 mm), images of much higher resolution can be produced. This allows for bigger enlargements and smooth gradation without the grain or blur that would characterize similarly enlarged images produced from smaller film formats. The larger size of the film also allows for better control of the depth of field and therefore more photographic creativity.

Cameras with a bellows typically support 'tilt and shift' of the lens. This permits landscape photography with the appearance of an extremely large depth of field – from closest foreground to the far horizon – to be achieved, by aligning the plane of focus with the subject plane of interest, using the Scheimpflug principle.

Compared with 35 mm, the main drawbacks are accessibility and price. While 35 mm cameras, film, and photo finishing services are generally widely available and cheap, medium format is usually limited to professional photography shops and can be prohibitively expensive. Also, medium-format cameras tend to be bulkier than their 35 mm counterpart.

Film handling
The medium-format film is usually roll film, typically allowing 8 to 32 exposures on one roll of film before reloading is needed. This is fewer than 35 mm cartridges, which typically take 12 to 36 pictures on one roll. This is somewhat offset by the fact that most medium-format systems used interchangeable film magazines, thereby allowing photographers to switch rolls quickly, allowing them larger numbers of exposures before needing to load new film or to change the film type. Some companies had bulk film backs that used 70 mm double-perforated film that allowed up to 75 feet of film to be loaded at one time. While rolls of large format film were produced at one time, their use was specialized, typically for aerial cameras installed in military aircraft or printing industry equipment.

Most large format film is sheet film, that is, film where each picture is on a separate piece of film, requiring that the camera be frequently reloaded, usually after every picture, sometimes using magazines of up to five pictures or reduction backs that allow multiple pictures on a single sheet of film. Medium-format sheet film was produced for some cameras, but these cameras tend to be smaller, lighter, and easier to use than large format gear. Sheet film was never commonly used in cameras smaller than medium format.

Film cost per exposure is directly related to the amount of film used, thus, the larger the film size, the more expensive each picture will be. An 8 by 10 in large-format negative is far more expensive than a 6 by 6 cm medium-format picture, which is substantially more expensive than a frame of 35 mm film.

35 mm cartridges are generally easier to load and unload from a camera than medium-format rolls. A 35 mm cartridge is placed inside a camera, and in most motorized cameras this is all that is needed; the camera loads the film and rewinds it into the cartridge for removal. Far fewer medium-format cameras are motorized, and medium-format roll film does not have sprocket holes, so loading often requires that marking on the backing paper of the film be lined up with markings on the camera, and on unloading, the backing paper must be carefully secured to protect the film from light.

120, 220 and 620 film
All medium-format cameras mass-produced today (as of 2022) use the 120 film format. Additionally, many are capable of using the 220 film format, effectively doubling the number of frames available with 120 film. Medium-format roll film is still available from specialty shops and photographic laboratories, yet it is not as ubiquitous as 135 (35 mm) film.

The 620 format was introduced by Kodak in 1931 as an alternative to 120. It was discontinued in 1995. The 620 format is essentially the same film on a thinner and narrower all-metal spool. While 620 film is required on a number of old Kodak Brownie cameras, many of these cameras can accommodate the slightly larger 120 rolls/spools. In other situations where the camera cannot accommodate a 120 spool, the 120 film can be rolled onto a 620 spool in a darkroom or changing bag.This film is shot in a variety of aspect ratios, which differ depending on the camera or frame insert used. The most common aspect ratios are 6×6 cm (square/1:1) and 6×4.5 cm (rectangular/4:3). Other frequently used aspect ratios are 6×7 cm, 6×9 cm, and 6×17 cm panoramic. The 6×4.5 cm format is usually referred to as "645", with many cameras that use this ratio bearing "645" in their product name. Cameras that can switch to different aspect ratios do so by either switching camera backs, by using a frame insert, or by use of special multi-format backs. All of these dimensions are nominal; actual dimensions are a bit different. For example, 6×7 cm might give an image on film that is actually 56×70 mm; this enlarges exactly to fill an 8×10 sheet of paper. Another feature of many medium-format models is the ability to use Polaroid instant film in an interchangeable back. Studio, commercial and architectural photographers value this system for its ability to verify the focus and exposure.

70 mm film – still versus cine
For some professional medium-format cameras, those used in school portraiture for example, long-roll film magazines were available. Most of these accommodated rolls of film that were 100 ft (30.5 m) long and 70 mm wide, sometimes with perforations, sometimes without. Some cameras, such as the Hasselblad, could be equipped with film magazines holding 15 foot rolls of double perforated 70 mm film passed between two cassettes. 70 mm was a standard roll film width for many decades, last used as late as the 1960s for 116 and 616 size roll films. It was also used for aerial photo-mapping, and it is still used by large format cinema systems such as IMAX.

70 mm film used in still cameras, like Mamiya and Hasselblad, and 70 mm print film used in IMAX projectors have the same gauge or height as 120 film. With 70 mm cine projector film, the perforations are inset by 2.5 mm to make room for the old-style optical sound tracks; a standard established by Todd-AO in the 1950s. IMAX cameras use 65 mm film, which have perforations and pitch that match-up to the 70 mm film used in IMAX projectors.

System cameras
[[Image:Mamiya 645 Super system.svg|thumb|right|320px|[[Mamiya 645]] Super and its possible configurations:

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Many professional medium-format cameras are system cameras, which means that they have various interchangeable parts. Like most 35 mm SLRs, these cameras usually support different lenses, but in addition it is also standard for medium-format system cameras to support different winding mechanisms, viewfinders, and camera backs. This flexibility is one of the primary advantages of medium-format photography.

Digital medium format
Digital photography came to the medium-format world with the development of digital camera backs, which can be fitted to many system cameras. Digital backs are a type of camera back that have electronic sensors in them, effectively converting a camera into a digital camera. These backs are used predominantly by professional photographers. As with film, due to the increased size of the imaging chip (up to twice that of a 35 mm film frame, and thus as much as 40 times the size of the chip in a typical pocket point-and-shoot camera) they deliver more pixels than consumer-grade cameras, and have lower noise. Features like fan cooling also improve the image quality of studio models.

This market began in 1992 when Leaf Systems Inc. released their first digital camera back (4 Megapixels), named the "DCB" (often described as 'a brick'). Initially mounted on Sinar Studio cameras, the camera backs were later moved to medium-format units. By the late 1990s, a number of companies produced digital camera backs of various types.

In the 2000s, the number of vendors of both high-end medium-format camera systems and digital backs began to decrease. The performance of digital SLRs cut into the sale of film-based medium-format systems, while the tremendous development expenses for medium-format digital systems meant that not all vendors could profitably compete. Contax and Bronica ceased production of cameras, Kodak stopped making their DCS series of backs, and camera and back manufacturers began to integrate.

Camera maker Hasselblad merged with digital imaging firm Imacon and partnered with Fuji to design and produce a new line of digital-friendly medium-format cameras, the H-Series. Since the manufacturer plans to sell digital backs integrated with the camera, other makers of digital backs are far less likely to be able to sell backs for this camera.

Camera maker Mamiya developed the 22MP Mamiya ZD in 2004, the first ever medium format DSLR. It also developed a ZD digital back but announced a partnership with back maker Phase One. Camera maker Sinar was taken over in stages by the digital camera back manufacturer and developer Jenoptik, and partnered with Rollei for the development of the Hy6 medium-format camera systems. DHW Fototechnik presented at photokina 2012 an updated version of the Hy6, called the Hy6 Mod2.

The Leaf Aptus 75S digital back offers 33MP resolution, with a shooting speed of 50 frames a minute. In early 2006 Hasselblad (H2D and H3D) and Phase One (P45) released a 39 megapixel back. In 2008, Phase One announced the P65+, a 60 megapixel back, the highest resolution single-shot digital back at that time (2008). Phase One continues to dominate high end non-interpolated imaging with the largest market share. Sinar continues to provide its primary Digital View Camera system while still supporting the HY6 medium format with a new platform independent eSprit 65 LV digital camera back. On 20 September 2010, Leaf released a 80MP digital back, the Aptus-II 12. The Leaf Aptus-II 12's sensor size of 53.7 mm × 40.3 mm is 92% of the area of a 56 mm × 41.5 mm standard-sized 6 × 4.5 frame, 69% of a 56 mm × 56 mm square-sized 6 × 6 frame, and 45% of the area of a 56 mm × 84 mm 6 × 9 frame.

Introduced in December 2010, the Pentax 645D is a 40 megapixel medium-format DSLR. The camera has a 44×33 mm image sensor and the raw file is in DNG format. It is the first digital version of the company's 645 medium-format camera system and it is compatible with the existing 645 system lenses.

In early 2014, the first Medium format cameras with a CMOS sensor instead of a CCD sensor were introduced by Phase One and Hasselblad. This sensor type gives better image quality mainly in High ISO with a dynamic range of up to 14 f-stops. Phase One and Hasselblad used the same 50MP CMOS sensor made by Sony. Similarly, the Pentax 645Z uses a 51 MP CMOS sensor.

Fujifilm started its GFX series of medium format digital cameras with the introduction of 50MP GFX 50S model released in January 2017, and as of mid 2024 has seven cameras in the GFX lineup, including three 51 MP models and four 102MP models.

Low-budget medium-format cameras

While most professional medium-format cameras are expensive, some cheaper plastic imports, such as the Diana and Holga cameras, are gaining in popularity for their creative potential. In the past, these kinds of cameras have been referred to as toy cameras, but now they are considered a real creative alternative to professional medium-format cameras and are sought after for the unique experimental results they can create.

Lower cost medium-format cameras like the Diana F+ and Belair X 6-12 are sold through various outlets, including the Austrian Lomography company. In 2007, Lomography brought the 1960s Diana camera back to the market with the Diana F+ camera, a system camera that allows photographers to experiment with interchangeable lenses, flashes, and film backs. These cameras are characterized by their plastic lenses, light leaks that oddly colorize an image, extreme vignetting, and color saturation. While these elements can be considered as flaws to photographers seeking perfect images, many people enjoy the "artistic" results. Because of the popularity of the Lomography photographic style, medium-format photography has seen a resurgence with amateur photographers.

Twin-lens reflex cameras (TLRs) and folders without the distortion and light leaks can be purchased on the used market in the same price range. The Chinese Seagull TLR and medium-format cameras from the former Soviet Union such as the Russian Lubitel and somewhat better made Ukrainian Kiev-Arsenal 60 and 88 are also available at moderate prices. These cameras can deliver quality images, although the lenses and camera bodies are not at the level of those from Swedish, German, and Japanese manufacturers. Depending on the condition of the camera, they can produce images ranging from the Lomographic style to images closer to their European and Japanese counterparts. In 2008 Lomography also reintroduced the previously discontinued Lubitel with the Lubitel 166+, a recreation of the original 1946 Lubitel camera with some new features including dual-format capability.

Since 2014, Lomography has been producing its medium format version of the Soviet-original Lomo LC-A camera, the Lomo LC-A 120, as compact option for medium format photographers.

Used folding cameras, TLRs, and box cameras are also an inexpensive option to shoot medium format. Many U.S.-made folders, including most of the mass-produced Kodak folders, use the discontinued 620 film requiring the user to respool 120 films or modify the film spool to fit.

Open source 3D printed cameras
There have been several projects to produce open source 3D printed cameras including K-Pan and Dora Goodman Cameras which produces medium format cameras as well as 35mm and large format compatible cameras. Goodman cameras are compatible with Mamiya press lenses and some Mamiya medium format film backs.

title: Medium format


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Count of Poitiers

Among the people who have borne the title of Count of Poitiers (Comte de Poitiers, Comes Pictaviensis; or Poitou, in what is now France but in the Middle Ages became part of Aquitaine) are: Carolingian Counts
 * Bodilon
 * Warinus (638–677), son of Bodilon
 * Hatton (735-778)

 * Bernard I of Poitiers (814-828)
 * Renaud (795–843)
 * Bernard II (840 - 844)
 * Emenon or Emeno (828 – 839), brother of Bernard II
 * Ranulph I (839–866)
 * Ranulph II (866–890), son of Ranulph I
 * Gauzbert (857–892)
 * Robert I (866–923)
 * Ebalus (or Ebles Manzer) (890–892) (illegitimate son of Ranulph II)(first reign– 890–893)(second reign– 902–935)
 * Aymar (892–902) (son of Emenon)
 * Ebalus (or Ebles Manzer) (restored) (902–935)
 * William I (935–963) (son of Ebalus)
 * William II (963–995) (son of William I)
 * William III (969–1030) (son of William II)
 * William IV (1030–1038) (1st son of William III)
 * Odo (Eudes) (1038–1039) (2nd son of William III)
 * William V (1039–1058) (3rd son of William III)
 * William VI (1058–1086) (4th son of William III)
 * William VII (1071–1126) (son of William VI)
 * William VIII (1099–1137) (son of William VII)
 * Eleanor, Duchess of Aquitaine
 * Louis VII of France (1137–1152) obtained title through marriage to Eleanor
 * Henry II of England (1152, 1156–1189) obtained title through marriage to Eleanor
 * William IX (1153–1156) son of Eleanor and Henry II of England
 * Richard I (1169–1196) son of Eleanor and Henry II of England
 * Otto (1196–1198)
 * Richard I again (1198–1199)
 * Richard II (1224) younger brother of Henry III of England
 * Alphonse I (1220–1271) son of Louis VIII of France
 * Philip I (1293–1322)
 * John I (1319–1364)
 * John II (1340–1416) son of John I
 * John III (1398–1417) son of Charles VI of France
 * Charles (1403–1461)
 * Francis (r. 1695–1715)
 * Francis (r. 1695–1715)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Count of Poitiers


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Messerschmitt

Messerschmitt AG was a German share-ownership limited, aircraft manufacturing corporation named after its chief designer Willy Messerschmitt from mid-July 1938 onwards, and known primarily for its World War II fighter aircraft, in particular the Bf 109 and Me 262. The company survived in the post-war era, undergoing a number of mergers and changing its name from Messerschmitt to Messerschmitt-Bölkow-Blohm before being bought by Deutsche Aerospace (DASA, now part of Airbus) in 1989.

Background
In February 1916, the south German engineering company MAN AG and several banks purchased the unprofitable aircraft builder Otto-Flugzeugwerke, starting a new company, Bayerische Flugzeugwerke AG (abbreviated B.F.W.). The articles of association were drawn up on 19 and 20 February, and completed on 2 March 1916. Details of the company were recorded in the Commercial Register with an equity capital of RM 1,000,000 on 7 March 1916. 36% of the capital was provided by the Bank für Handel und Industrie, Berlin, 30% by MAN AG and 34% by Hermann Bachstein, Berlin. The first Chairman of the Board of Management was Peter Eberwein, who had previously been employed at Albatros Flugzeugwerke.

Due to the need for immediate aircraft production for the ongoing war, there was no time for development work and BFW manufactured aircraft under licence from Albatros Flugzeugwerke. Within a month of being set up, the company was able to supply aircraft to the war ministries of Prussia and Bavaria. However, major quality problems were encountered at the start. The German air crews frequently complained about the serious defects that appeared in the first machines from BFW. The same thing had happened with the aircraft from the predecessor company run by Gustav Otto. It was only organizational changes and more intensive supervision of the assembly line that succeeded in resolving these problems by the end of 1916. BFW then started turning out over 200 aircraft a month, with their workforce growing to 3,000 and becoming one of the largest aircraft manufacturers in Bavaria.

The end of the war hit BFW hard, since military demand for aircraft collapsed. The company's management were forced to look for new products with which to maintain their position in the market. Since World War I aircraft were largely built from wood to keep their weight down, BFW was equipped with the very latest joinery plant. The company still held stocks of materials sufficient for about 200 aircraft, and worth 4.7 million reichsmarks. The machinery and the materials were then used for the production of furniture and fitted kitchens. In addition, from 1921 onwards, the company manufactured motorcycles of its own design under the names of Flink and Helios.

In the autumn of 1921, Austrian financier Camillo Castiglioni first announced his interest in purchasing BFW. While most of the shareholders accepted his offer, MAN AG initially held on to its shareholding in BFW, but Castiglioni wanted to acquire all the shares. He was supported in this by BMW's Managing Director Franz Josef Popp who, in a letter to the chairman of MAN, described BFW as a "dead factory, which possesses no plant worth mentioning, and consists very largely of dilapidated and unsuitable wooden sheds situated in a town that is extremely unfavorable for industrial activities and whose status continues to give little cause for enthusiasm". Apparently Popp was still in close contact with Castiglioni and was perhaps even privy to the latter's plans for merging BMW with BFW. It was probably in the spring of 1922 that Castiglioni and Popp persuaded MAN to give up its shares in BFW, so that now the company belonged exclusively to Castiglioni. Then, in May of the same year, when the Italian-born investor was able to acquire BMW's engine business from Knorr-Bremse AG, nothing more stood in the way of a merger between the aircraft company BFW and the engine builders BMW.

Reestablishment
Bayerische Flugzeugwerke (BFW/Bavarian Aircraft Works) was reformed in 1926, in Augsburg, Bavaria, when Udet Flugzeugbau GmbH was changed into a joint-stock company. In the early stages, BMW AG held a stake in this company and was represented by Josef Popp, who held a place on the Supervisory Board.

Willy Messerschmitt joined the company in 1927 as chief designer and engineer and formed a design team.

One of the first designs, the Messerschmitt M20, was a near-catastrophe for the designer and the company. Many of the prototypes crashed, one of them killing Hans Hackmack, a close friend of Erhard Milch, the head of Deutsche Luft Hansa and the German civil aviation authorities. Milch was upset by the lack of response from Messerschmitt and this led to a lifelong hatred towards him. Milch eventually cancelled all contracts with Messerschmitt and forced BFW into bankruptcy in 1931. However, Messerschmitt's friendship with Hugo Junkers prevented a stagnation of the careers of him and BFW, which was started again in 1933. Milch still prevented Messerschmitt's takeover of the BFW until 1938, hence the designation "Bf" of early Messerschmitt designs.

Messerschmitt promoted a concept he called "light weight construction" in which many typically separate load-bearing parts were merged into a single reinforced firewall, thereby saving weight and improving performance. The first true test of the concept was in the Bf 108 Taifun sports aircraft, which would soon be setting all sorts of records. Based on this performance the company was invited to submit a design for the Luftwaffe's 1935 fighter contest, winning it with the Bf 109, based on the same construction methods.

From this point on Messerschmitt became a favorite of the Nazi party, as much for his designs as his political abilities and the factory location in southern Germany away from the "clumping" of aviation firms on the northern coast. BFW was reconstituted as "Messerschmitt AG" on 11 July 1938, with Willy Messerschmitt as chairman and managing director. The renaming of BFW resulted in the company's RLM designation prefix changing from "Bf" to "Me" for all newer designs that were accepted by the RLM after the acquisition date. Existing types, such as the Bf 109 and 110, retained their earlier designation in official documents, although sometimes the newer designations were used as well, most often by subcontractors, such as Erla Maschinenwerk of Leipzig. In practice, all BFW/Messerschmitt aircraft from the Bf 108 four-seat touring monoplane, to the Bf 163 light observation aircraft (which competed unsuccessfully for the government contract won by the rival Fieseler Fi 156 design) were prefixed "Bf", all later types with "Me".

World War II
During the war Messerschmitt became a major design supplier, their Bf 109 and Bf 110 forming the vast majority of fighter strength for the first half of the war. Several other designs were also ordered, including the enormous Me 321 Gigant transport glider, and its six-engined follow on, the Me 323. However, for the second half of the war, Messerschmitt turned almost entirely to jet-powered designs, producing the world's first operational jet fighter, the Me 262 Schwalbe ("Swallow"). They also produced the DFS-designed Me 163 Komet, the first rocket-powered design to enter service. Messerschmitt relied heavily on slave labour to produce much of the parts needed for these aircraft during the second half of World War II; these parts were assembled in an enormous tunnel system in Sankt Georgen an der Gusen, Austria. Slave labour was provided by inmates of the brutal KZ Gusen I and Gusen II camps, and by inmates from nearby Mauthausen concentration camp, all located near the St. Gorgen quarries. 40,000 inmates from Spain, Italy, Poland, Slovenia, France, Russia, Hungarian Jews and twenty other nationalities were murdered during the production of these aircraft at KZ Gusen. Messerschmitt officials maintained barracks at the concentration camp to oversee the work being done by the inmates. Messerschmitt, and its executive Willy Messerschmitt also occupied the famed Villa Tugendhat in Brno, Czech Republic, designed by Mies van der Rohe and Lilly Reich in the 1920s; the Messerschmitt aircraft factory office and the Gestapo occupied the property during the war.

Messerschmitt had its share of poor designs as well; the Me 210, designed as a follow-on to the 110, was an aerodynamic disaster that almost led to the forced dissolution of the company. The design problems were eventually addressed in the Me 410 Hornisse, but only small numbers were built before all attention turned to the 262. Later in the war, in competition with the Junkers Ju 390 and the unbuilt, February 1943-initiated Heinkel He 277, Messerschmitt also worked on a heavy Amerika Bomber design, the Me 264, which flew in prototype form — with three prototype airframes built, the first of which flew in December 1942 — but was too late to see combat.

Post-war
For ten years after World War II, the company was not allowed to produce aircraft. One alternative the company came up with was the three-wheeled motorcycle/bubble car or Kabinenroller (cabinscooter) KR175 / KR200, designed by an aircraft engineer, Fritz Fend.

The cars were actually made by Fend's own company in the Messerschmitt works at Regensburg, and Willy Messerschmitt had very little to do with the vehicles other than ruling that they carried his name. Production of the KR200 ceased in 1964.

The Messerschmitt factory also produced prefabricated houses, which were designed as "self-building-kits" mainly based on an alloy framework.

Return to aviation
On 6 June 1968, Messerschmitt AG merged with the small civil engineering and civil aviation firm Bölkow, becoming Messerschmitt-Bölkow. The following May, the firm acquired Hamburger Flugzeugbau (HFB). The company then changed its name to Messerschmitt-Bölkow-Blohm (MBB). In 1989 MBB was taken over by DASA. DASA later operated as "EADS Germany", which is now Airbus.

Other types of aircraft

 * Messerschmitt Me 109TL

Missiles

 * Enzian

Microcars

 * KR175
 * KR200

title: Messerschmitt


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Operon

In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splicing to create monocistronic mRNAs that are translated separately, i.e. several strands of mRNA that each encode a single gene product. The result of this is that the genes contained in the operon are either expressed together or not at all. Several genes must be co-transcribed to define an operon.

Originally, operons were thought to exist solely in prokaryotes (which includes organelles like plastids that are derived from bacteria), but their discovery in eukaryotes was shown in the early 1990s, and are considered to be rare. In general, expression of prokaryotic operons leads to the generation of polycistronic mRNAs, while eukaryotic operons lead to monocistronic mRNAs.

Operons are also found in viruses such as bacteriophages. For example, T7 phages have two operons. The first operon codes for various products, including a special T7 RNA polymerase which can bind to and transcribe the second operon. The second operon includes a lysis gene meant to cause the host cell to burst.

History
The term "operon" was first proposed in a short paper in the Proceedings of the French Academy of Science in 1960. From this paper, the so-called general theory of the operon was developed. This theory suggested that in all cases, genes within an operon are negatively controlled by a repressor acting at a single operator located before the first gene. Later, it was discovered that genes could be positively regulated and also regulated at steps that follow transcription initiation. Therefore, it is not possible to talk of a general regulatory mechanism, because different operons have different mechanisms. Today, the operon is simply defined as a cluster of genes transcribed into a single mRNA molecule. Nevertheless, the development of the concept is considered a landmark event in the history of molecular biology. The first operon to be described was the lac operon in E. coli. The 1965 Nobel Prize in Physiology and Medicine was awarded to François Jacob, André Michel Lwoff and Jacques Monod for their discoveries concerning the operon and virus synthesis.

Overview
Operons occur primarily in prokaryotes but also rarely in some eukaryotes, including nematodes such as C. elegans and the fruit fly, Drosophila melanogaster. rRNA genes often exist in operons that have been found in a range of eukaryotes including chordates. An operon is made up of several structural genes arranged under a common promoter and regulated by a common operator. It is defined as a set of adjacent structural genes, plus the adjacent regulatory signals that affect transcription of the structural genes.5 The regulators of a given operon, including repressors, corepressors, and activators, are not necessarily coded for by that operon. The location and condition of the regulators, promoter, operator and structural DNA sequences can determine the effects of common mutations.

Operons are related to regulons, stimulons and modulons; whereas operons contain a set of genes regulated by the same operator, regulons contain a set of genes under regulation by a single regulatory protein, and stimulons contain a set of genes under regulation by a single cell stimulus. According to its authors, the term "operon" is derived from the verb "to operate".

As a unit of transcription
An operon contains one or more structural genes which are generally transcribed into one polycistronic mRNA (a single mRNA molecule that codes for more than one protein). However, the definition of an operon does not require the mRNA to be polycistronic, though in practice, it usually is. Upstream of the structural genes lies a promoter sequence which provides a site for RNA polymerase to bind and initiate transcription. Close to the promoter lies a section of DNA called an operator.

Operons versus clustering of prokaryotic genes
All the structural genes of an operon are turned ON or OFF together, due to a single promoter and operator upstream to them, but sometimes more control over the gene expression is needed. To achieve this aspect, some bacterial genes are located near together, but there is a specific promoter for each of them; this is called gene clustering. Usually these genes encode proteins which will work together in the same pathway, such as a metabolic pathway. Gene clustering helps a prokaryotic cell to produce metabolic enzymes in a correct order. In one study, it has been posited that in the Asgard (archaea), ribosomal protein coding genes occur in clusters that are less conserved in their organization than in other Archaea; the closer an Asgard (archaea) is to the eukaryotes, the more dispersed is the arrangement of the ribosomal protein coding genes.

General structure

An operon is made up of 3 basic DNA components:

 * Promoter – a nucleotide sequence that enables a gene to be transcribed. The promoter is recognized by RNA polymerase, which then initiates transcription. In RNA synthesis, promoters indicate which genes should be used for messenger RNA creation – and, by extension, control which proteins the cell produces.
 * Operator – a segment of DNA to which a repressor binds. It is classically defined in the lac operon as a segment between the promoter and the genes of the operon. The main operator (O1) in the lac operon is located slightly downstream of the promoter; two additional operators, O2 and O3 are located at -82 and +412, respectively.  In the case of a repressor, the repressor protein physically obstructs the RNA polymerase from transcribing the genes.
 * Structural genes – the genes that are co-regulated by the operon.

Not always included within the operon, but important in its function is a regulatory gene, a constantly expressed gene which codes for repressor proteins. The regulatory gene does not need to be in, adjacent to, or even near the operon to control it.

An inducer (small molecule) can displace a repressor (protein) from the operator site (DNA), resulting in an uninhibited operon.

Alternatively, a corepressor can bind to the repressor to allow its binding to the operator site. A good example of this type of regulation is seen for the trp operon.

Regulation
Control of an operon is a type of gene regulation that enables organisms to regulate the expression of various genes depending on environmental conditions. Operon regulation can be either negative or positive by induction or repression.

Negative control involves the binding of a repressor to the operator to prevent transcription.

 * In negative inducible operons, a regulatory repressor protein is normally bound to the operator, which prevents the transcription of the genes on the operon. If an inducer molecule is present, it binds to the repressor and changes its conformation so that it is unable to bind to the operator. This allows for expression of the operon. The lac operon is a negatively controlled inducible operon, where the inducer molecule is allolactose.
 * In negative repressible operons, transcription of the operon normally takes place. Repressor proteins are produced by a regulator gene, but they are unable to bind to the operator in their normal conformation. However, certain molecules called corepressors are bound by the repressor protein, causing a conformational change to the active site. The activated repressor protein binds to the operator and prevents transcription. The trp operon, involved in the synthesis of tryptophan (which itself acts as the corepressor), is a negatively controlled repressible operon.

Operons can also be positively controlled. With positive control, an activator protein stimulates transcription by binding to DNA (usually at a site other than the operator).

 * In positive inducible operons, activator proteins are normally unable to bind to the pertinent DNA. When an inducer is bound by the activator protein, it undergoes a change in conformation so that it can bind to the DNA and activate transcription. Examples of positive inducible operons include the MerR family of transcriptional activators.
 * In positive repressible operons, the activator proteins are normally bound to the pertinent DNA segment. However, when an inhibitor is bound by the activator, it is prevented from binding the DNA. This stops activation and transcription of the system.

The lac operon
The lac operon of the model bacterium Escherichia coli was the first operon to be discovered and provides a typical example of operon function. It consists of three adjacent structural genes, a promoter, a terminator, and an operator. The lac operon is regulated by several factors including the availability of glucose and lactose. It can be activated by allolactose. Lactose binds to the repressor protein and prevents it from repressing gene transcription. This is an example of the derepressible (from above: negative inducible) model. So it is a negative inducible operon induced by presence of lactose or allolactose.

The trp operon
Discovered in 1953 by Jacques Monod and colleagues, the trp operon in E. coli was the first repressible operon to be discovered. While the lac operon can be activated by a chemical (allolactose), the tryptophan (Trp) operon is inhibited by a chemical (tryptophan). This operon contains five structural genes: trp E, trp D, trp C, trp B, and trp A, which encodes tryptophan synthetase. It also contains a promoter which binds to RNA polymerase and an operator which blocks transcription when bound to the protein synthesized by the repressor gene (trp R) that binds to the operator. In the lac operon, lactose binds to the repressor protein and prevents it from repressing gene transcription, while in the trp operon, tryptophan binds to the repressor protein and enables it to repress gene transcription. Also unlike the lac operon, the trp operon contains a leader peptide and an attenuator sequence which allows for graded regulation. This is an example of the corepressible model.

Predicting the number and organization of operons
The number and organization of operons has been studied most critically in E. coli. As a result, predictions can be made based on an organism's genomic sequence.

One prediction method uses the intergenic distance between reading frames as a primary predictor of the number of operons in the genome. The separation merely changes the frame and guarantees that the read through is efficient. Longer stretches exist where operons start and stop, often up to 40–50 bases.

An alternative method to predict operons is based on finding gene clusters where gene order and orientation is conserved in two or more genomes.

Operon prediction is even more accurate if the functional class of the molecules is considered. Bacteria have clustered their reading frames into units, sequestered by co-involvement in protein complexes, common pathways, or shared substrates and transporters. Thus, accurate prediction would involve all of these data, a difficult task indeed.

Pascale Cossart's laboratory was the first to experimentally identify all operons of a microorganism, Listeria monocytogenes. The 517 polycistronic operons are listed in a 2009 study describing the global changes in transcription that occur in L. monocytogenes under different conditions.

title: Operon


text:
Talk:Pentium 4

Brand-name vs. code name for chip vs. code name for microarchitecture
This distinction does not only make sense, it is also most relevant, because e.g. there are chips marketed under the "Pentium 4"-brand that support the x86 (32-bit) instruction set and others which implement x86-64 (64-bit) instruction set. Additionally there are a bunch of extensions like – e.g. MMX, SSE4 – that are implemented by some and not by other processors marketed under the same brand. One could market very different things under the same brand: Blue Digshit seems to still be available. User:ScotXW t@lk 13:59, 7 December 2017 (UTC)
 * 1) "Pentium 4" is a brand name, so are "Core 2 Duo", "Core i3-xxxx", etc.
 * 2) Nehalem (microarchitecture) is a code name for some microarchitecture
 * 3) Clarksfield (microprocessor) is a code name for some chip/die/package fitting into some CPU socket

Appropriate?
Overclockers mistakenly believed that the Northwood was a better choice for overclocking, while in reality the Prescott would outperform the Northwood and generate less heat in overclocked conditions. ^that's still generally found to be false, atleast for the early revisions of prescott. it wasn't until prescott improved a fair bit as far as manufacturing went where that was true as initial prescott chips didn't clock as high as Northwood —Preceding unsigned comment added by 76.87.89.227 (talk) 04:04, 8 March 2008 (UTC)

Ram types and the Pentium 4
Does anyone know what types of RAM work with the P4? What's the relationship between FSB speed and RAM? Should this article link to others describing this relationship?

Mr. Jones 11:33, 24 Sep 2004 (UTC)
 * THe P4 has supported PC100 SDRAM, PC133 SDRAM, PC800 RDRAM, PC1066 RDRAM, DDR266 SDRAM, DDR400 SDRAM, DDR2-266 SDRAM, DDR2-400, and perhaps a few I've missed. Last Avenue 00:14, 25 January 2006 (UTC)
 * Usually the FSB clock is the same as the RAM clock. For example, Intel's current 200MHz FSB corresponds with the RAM clock, 200MHz. DDR400 runs at 200MHz but is called DDR400 because of DDR.
 * Some types to add: PC-600/PC-700 Rambus, all DDR-1 RAM types (PC-1600, PC-2100, PC-2700 and PC-3200), at least all available DDR-2 Ram types released until now. Memory support always depends on the motherboard used, they usually support only one type of RAM. --Denniss 03:09, 25 January 2006 (UTC)

 * Up to Nehalem (microarchitecture) the memory controller was part of the North bridge. I also marked it here: Template:Intel_processor_roadmap. So look up the appropriate chip set and that article should tell the supported RAM-type. The socket-article should also tell. Or look it up in the list: List of Intel chipsets User:ScotXW t@lk 12:25, 7 December 2017 (UTC)

Dates Right?
Processor Cores>Northwood> "A 2.4 GHz P4 was released in April 2002, and the bus speed increased from 400 MT/s to 533 MT/s for a 2.53 GHz part in May, 2.6 and 2.8 GHz parts in August, and a 3.06 GHz Pentium 4 arrived in November."

These dates dont seem right to me. If anyone has sources or can back these up. Im pretty sure you could get 2.4Ghz P4's well before April 2002.

No comment about the date, however this statement in the main document needs to read: "A 2.4 GHz P4 was released in April 2002, and the bus speed increased from 400 MT/s to 533 MT/s for a 2.26 GHz, 2.4 GHz, and 2.53 GHz part in May, 2.6 and 2.8 GHz parts in August, and a 3.06 GHz Pentium 4 arrived in November." --I personally own a 2.26 533 FSB and I know a 2.4 also existed in a 533 FSB.

 * I'm right now looking at a Pentium(R)4 labeled Intel (R)(C) '01.  2.40GHz/512/533 SL6sH. Intel website (https://ark.intel.com/content/www/us/en/ark/products/27438/intel-pentium-4-processor-2-40-ghz-512k-cache-533-mhz-fsb.html)  "launch date Q1'02". "May" isn't Q1, so the May date given here may be wrong. It doesn't seem to be referenced.
 * It still seems like a long lead time, but I guess Intel didn't 'release' the 2001 parts until April/May. — Preceding unsigned comment added by 121.200.27.15 (talk) 08:13, 25 August 2023 (UTC)

Or maybe the "release" date is a retail release date? — Preceding unsigned comment added by 121.200.27.15 (talk) 08:23, 25 August 2023 (UTC)

Removed text
I removed, at least for now, the following PR blurb:

''In addition to making significant increases in performance from the Pentium III class of CPUs. The Pentium 4 produces low amount of heats compared to its AMD counterparts, and features a silver electroplated sheet of copper ontop of the core to protect it. A retention mechanism which placed the physical load of the cooling mechanism on the motherboard via a retention mechansim mounted on holes through the motherboard, this is important as shearing off of the retention tabs on the CPU socket. is a common problem when some heatsinks. In addition to producing less heat, each version version of the core for Pentium 4 undergoes testing to determine its maximum safe operable tempature, heat output, maximum safe core voltage. The Pentium 4 also includes safeguards to make use of the information gathered about the maximum safe operable speed of the Pentium 4. If the Pentium 4's on core thermal diode reads higher than the maximum safe operable tempature, it will descrease the core speed to reduce output. This is very important, as even if a Pentium 4s cooling mechanism somehow becomes detached, it will survive the incident.''

Quite a bit needs to be done with this to correct some misconceptions.

 * One needs to be careful about making "significant increases in performance" generalisations. The thing about the P4 is that it ticks very fast, but does relatively little work per tick. In terms of IPC, it was a major step backwards. In terms of raw clockspeed it was (eventually) a major step forward. The original P4s were, frankly, slugs. They got better - much better - when Northwood arrived.
 * The "low power, low heat" thing is nonsense. Compare, for example, the P4 1.5GHz and the (slightly faster) Thunderbird 1000c - 52W at full load vs 54W - a very marginal difference indeed. (I'll try to find time to dig out a few other examples later tonight.) Essentially, provided you compare similar process technology parts that have similar computational power, there is very little difference between P4 and Athlon. AMD claim that the Athlon is more power efficient than the P4, though I think that they maybe take it a little too far.) (The P-III, on the other hand, is remarkably power efficient. A 1.8 micron P-III 1000 - which was the equal of a P4 1.5 and not far behind the Athlon 1000c, performance wise - consumed just 33W.)

Damn! I'm out of time - I'll come back and finish this off a little later tonight. Tannin 09:49 Jan 30, 2003 (UTC)

OK, more power consumption figures, as promised. First, I have to apologise for my mistake earlier tonight. I said that power consumption is, in fact, roughly the same between the Athlon and the P4. I was wrong. I've been checking my facts, and the Athlon clearly uses considerably less power than the P4 to do the same amount of work. The numbers above compare the maximum consumption of the Thunderbird 1000 to the typical consumption of the P4. The correct figures are:
 * 54W: 0.18u Thunderbird 1000C
 * 75W: 0.18u Pentium 4 1.5 (Socket 423)
 * (There were at least three variants of the 1.5 - the other two are 76W and 79W.)

Now let's consider the next performance level. There was hot debate as to which of these two chips was, in fact, faster, the P4 1.7 or the Thunderbird 1400. Most experts - about two out of three - regarded the Athlon as the faster of the two, but some argued the other way, and everone agrees that they were very close.
 * 72W: 0.18u Thunderbird 1400
 * 87W: 0.18u Pentium 4 1.7 (Socket 423)

Now let's look at the next step again (and another hotly debated "which is the best of two rather similar chips" contest. The consensus is that the XP 1700 was comfortably faster than a P4 2.0 - remembering that this is the old 256k 1.8 micron P4, not the vastly improved 0.13u Northwood that came along in January 2002.
 * 64W: 0.18u Athlon XP 1700+
 * 96W: 0.18u Pentium 4 2.0 (Socket 423)
 * 100W: 0.18u Pentium 4 2.0 (Socket 478)

Just for fun, let's throw in the Northwood as well - but we must remember that in doing this we are not comparing like with like, as the 2.0 Northwood is faster than an XP 1700 and made on a different and much cooler running process. I'll also include the 0.13 Athlon at 2000+ for comparison
 * 69W: 0.13u Pentium 4 (Northwood)
 * 62.8W: 0.13u XP 2000 (Thoroughbred)

Finally, let's take the two current-model 2600 parts:
 * 68.3W 0.13u Athlon XP 2600+
 * 81W: 0.13u Pentium 4 2.6 (Northwood)

Next: A retention mechanism ... this is important as shearing off of the retention tabs on the CPU socket is a common problem when some heatsinks. Sorry, but that's pure PR bull. In my 20+ years of working with PCs, I have seen this problem in the flesh exactly once. It was toward the end of last year, about October, I think, and the CPU in question was, of all things, a Cyrix 686. We devised an ugly but effective workaround of the sticky-tape and string variety, but then the customer decided it ws time he had an upgrade anyway, so we just threw the motherboard away. At the time it was about four or five years old and worth maybe US$10. Never seen it happen to an Athlon or a P4.

 * It has happened to me. The retention tabs on the Socket 370 snapped off, this happened twice. It was on a Via Apollo 133T (694T), MSI Model 6318 Version 5. I was using the stock Retail Pentium III 1.13ghz fan.Patcat88 17:19, 25 Jan 2004 (UTC)

Each version version of the core for Pentium 4 undergoes testing to determine its maximum safe operable tempature, heat output, maximum safe core voltage. Yup. Quite right. Each version of every other CPU manufactured in the last ten or twenty years also. Not to mention vido card GPUs, RAM, and anything else that uses large transistor counts.

''If the Pentium 4's on core thermal diode reads higher than the maximum safe operable tempature, it will descrease the core speed to reduce output. This is very important, as even if a Pentium 4s cooling mechanism somehow becomes detached, it will survive the incident.'' And here, at last, we finally strike gold. This is an important feature of the P4 design, and (unless someone gets in first) I'll return this to the entry. It's very different to the Athlon. The P4 clock throttles (i.e., slows itself down) in a user transparent way. The only way you become aware of the fact that your P4 is overheating is when you notice that it's not performing properly. (By the way, this aspect of the P4 design makes benchmarking very difficult - unless you go to a lot of trouble with cooling, you never get the same result twice running.) In contrast, the Athlon delivers 100% of its rated performance 100% of the time. When the Athlon's thermal diode hits a pre-set critical temperature, it cuts the power. It's a diference of design philosophy: the Intel part is prepared to sacrifice performance to avoid an unintended shutdown, the AMD is prepared to risk an unintended shutdown in order to deliver 100% performance. Neither chip can self-destruct unless the technician is grossly incompetent. (Note that older model Athlons - in particular the Thunderbirds - relied on motherboard manufacturers to provide effective thermal sensing. Often, they didn't. I always regarded that as a design error on AMD's part - personally, I wouldn't trust the average motherboard manufacturer to tie his own shoelaces 10 times out of 10. Tannin 15:40 Jan 30, 2003 (UTC)

 * Ack! Please don't throw perfectly good Socket 7 motherboards away. Lots of people would be happy to have them Crusadeonilliteracy 14:18, 16 Jan 2004 (UTC)

Intel Cores
I made a list of intel cores, there are some not included in this article though. I dont know much about them but maybe someone can include some information? Read the Inqurier article at the end, it is very good.

List of Intel cores

This is a list of Intel microchip 'cores'. A core can be considered a chip design.

 * Willamette
 * Netburst core
 * Prescott
 * Tejas
 * Dothan
 * Northwood

Intel faces performance struggle for two hard years, The Inquirer

--ShaunMacPherson 01:21, 16 Oct 2004 (UTC)

 * Netburst is not really a core, it is the underlying architecture for all P4 variants. Dothan is a Pentium M core that should be treated in the respective article. --Echoray 12:42, 16 Oct 2004 (UTC)

Disambig?
I noticed that Willamette redirects here. Do you think we should add a disambig notice on the top in case people want the Willamette River or Willamette University?--Clipdude 08:15, 9 Nov 2004 (UTC)

NPOV
''Also of concern was the fact that reviews showed it took a 5.2 GHz Prescott core to match the performance of an Athlon FX-55. Considering Intel boasted at launch the Pentium 4 architecture was designed for 10 GHz operation, this can be seen as one of the most significant, certainly most public, engineering shortfalls in Intel’s history. ''

This is not NPOV or correct - a 5.2 Ghz Prescott will soundly beat an FX-55 in multimedia encoding, as can be seen in the Mp3 encoding graph where the 5.2ghz Prescott beat the FX-55 by 35%, and the 4ghz Prescott beat it by 6%. The same applies for video encoding. The review only shows the Prescott has to be clocked at 5.2 Ghz to beat the Prescott in games and WinRAR compression. The next two paragraphs are also highly opinionated. --Defsac 02:01, 18 Apr 2005 (UTC)

Willimette
"Many observers concluded that the Thunderbird was still faster overall, but the performance gap was sufficiently narrow that it was not unreasonable for partisans of either camp to claim superiority. For Intel, this was a very significant achievement. The firm had held the x86 CPU performance crown for nearly 16 years straight, with only two brief exceptions prior to the release of the AMD Athlon."

I disagree with this statement, as it only refers to the SD-ram utilisation of this CPU, where'is if used with RD-ram, was far superior to the rival offerings of the time. Infact, it took a whole 2 yrs untill AMD and Intel itself to better the raw long-code performance of an RDRAM chipset/cpu of a bygone era, even then only just matched it, and it wasnt untill a futher revision by both companies that it was bettered. The above reporting shows how deaply the bias was against RAMBUS, and the lenghts some reporters went to to discredit them.

 * Uhh, the Willamette was never a superior CPU. It didn't have enough cache, or clock speed, to compete with Athlon, especially when Athlon XP arrived. Pentium 3 could run with most Willamette systems. Of course, SDRAM versions of Willamette were even worse off because they were simply crippled by the lack of bandwidth (Netburst loves bandwidth). --Swaaye 06:09, 1 June 2006 (UTC)

Mobile Pentium 4
There in no information at all on the Mobile Pentium 4 processors (both Mobile Pentium 4 and Pentium 4 M). Some info can be obtained from Mobile Pentium 4 and Pentium 4 M product information pages. Those processors were widely used before Pentium M was launched. -- Eagleamn 13:39, September 4, 2005 (UTC)
 * I just added some info on the P4 mobile chips, hopefully someone can add to it and help make it clearer. There aren't a lot of good resources on these chips, still trying to find some release dates, phase out dates, processor speeds etc... this page helped me some. Any help would be welcome! --Fxer 16:46, 7 October 2005 (UTC)

dual core
under the dual core section, it says presler is based on the 65nm version of smithfield. To be more clear it should say the 65nm single cores of smithfield are called cedar mill,

Dual Core
Some vandal made a comment about how the L2 cache bottleneck is not eliminated by providing each core with an independent cache, which is completely untrue. He also tried to assert that the Presler will not be a "true Dual-Core" chip, but rather a Multi Core chip. Well, unless Intel magicly ships presler with three or four cores (not damm likely), the distinction between dual-core and multi-core is pointless; I corrected the paragraph to reflect reality more closely.

Unsourced opinions
I removed this comment:
 * In retrospect, the Pentium III core was technologically superior to Pentium 4, which can be seen as an example of what happens when marketing teams draw up technical project specifications.

This is a common opinion (Pentium 3 was superior) combined with rather derisive speculation (marketing did it).

The first needs a source and the second needs to go—unless a more informed source can also be found for that one. 82.92.119.11 23:29, 18 January 2006 (UTC)

 * Why the Prescott ended up in such a disaster can be attributed to internal politics at Intel. The marketing department wanted ever higher clock speeds, to differentiate their products from AMD. Processor design was dictated by marketing needs, rather than architectural requirements. Careers were then built on the concept of higher clock speeds, and the termination of the P4 project when it finally came, had consequences for many members of the management team at the well-funded desktop division.

Is there a source for this? I'm in the unfortunate situation of not being able to get a reliable source for this in order to include it in a report that is to be peer-reviewed. If anyone knows, please contact me via my talk page. I think it's probably fair to say that these comments fairly reflect what people think happened, so I'm sure it could be modified to be acceptable even if a great source can't be found. Important questions: Who made the decisions? Who got fired? The story makes sense, but without a reliable source and some firmer details this text can't be left as is. Gantlord 11:11, 8 December 2006 (UTC)

 * In his book "The Pentium Chronicles" Bob Colwell, one of the Willamette chief architects wrote that he left Intel after he realized it was a mistake to bet on ever higher clockspeed but couldn't make a dent into the product roadmaps. He says something like "Willamette was not fun". Unfortunately, I don't have the book at hand anymore. --Echoray 12:26, 8 December 2006 (UTC)

Thanks echoray, I also turned up this if people think it's interesting: http://www.bit-tech.net/bits/2006/08/17/marketing_blunders_of_our_time/1.html Gantlord 13:04, 8 December 2006 (UTC)

Rendering Errors
I have rendering errors in internet explorer on the main page. The icon of the P4 obscures some of the text. Could this be changed? (i will try myself).--BorisFromStockdale 20:28, 19 January 2006 (UTC)

Best Processor
come on, unpack those loops, first make function compounding, bit processing style then aply the info to b processed, use that pipeline n that predication for something get into 6th generation microchips able of evn more than 1000 instr/1T n most important:dont mention me

Florin Matei — Preceding unsigned comment added by 93.118.212.93 (talk) 08:29, 10 March 2012 (UTC)

What is the best proccesor out there?

Depends. Intel Core 2 is the best for multitasking and its great for laptops because it consumes little power, same goes with the original Intel Core. The Pentium 4 is great for video encoding and single-core applications because of its raw power, brute force and high clock speed but its not very efficient and runs VERY hot (not suitable for laptops) although some of the problems were fixed with Cedar Mill. The P4 is okay at multitasking because it has hyperthreading. The Pentium D is like two P4's stuck together so its better than the P4 multitasking but otherwise very similar (still hot and inefficient). The Celeron and Pentium dual core are weak but very cheap. So it depends on what you want to get out of your system. The Intel Core2 runs at a slower speed but its multicore so when your running two programs, the second core will kick in and youll be able to do your work two times faster. Its also based on PIII so its more efficient. It also has alot of cache and a faster front bus speed. However, the P4 will beat it in single-threaded applications because of its higher clock speed (the most important part of a processor). You also need to take into account the other components, such as RAM size/speed and Hard drive speed. 203.184.7.28 (talk) 22:55, 20 December 2007 (UTC)

 * Technically the Core 2 is based on the Pentium M, which is based on the PIII. Your comment about the clock speed being the most important part of a processor is wrong.  The Core 2 still beats the P4 even with its lower clock speed because it can do more work in each clock cycle.  The P4 was designed to have a high clockspeed (since "MHz sells").  This lead to there being a lot of heat produced, making the Core 2 necessary.  Overall, you want a Core 2 (or something based on Core), NOT a P4 (or P4 based chip).  (In AnandTech's Core 2 review, there were several benchmarks where the cheapest C2D at launch (E6300) outperformed the previous P4 based flagship CPU (PD 965))  Also, although RAM size does have a significant effect on performance as well as the RAM size (although that is a smaller effect), the hard drive speed does not have any noticable effect on performance.  -- Imperator3733 (talk) 17:04, 21 December 2007 (UTC)

List of Intel Pentium 4 microprocessors
I've recently created a List of Intel Pentium 4 microprocessors page in the same vein as the lists of AMD processors. I think there are enough P4s that a list page is justified, and I've never been comfortable with the idea that AMD processors get list pages and Intel processors don't. Right now, it's a subpage of my user page as I'm considering it a work in progress. After filling in some more stuff, it should be ready to be moved into the main namespace. I'd also like to hear any thoughts/comments/concerns before I do so as well. Jgp 11:05, 1 April 2006 (UTC)
 * Looks good. Maybe replace the FSB MHz with MT/s (Megatransfer). This shoudl also be done for the AMD listings using the wrong MHz. --Denniss

Removing the table
Since List of Intel Pentium 4 microprocessors exists, I'd like to propose deleting the huge table on this page, due to the redundancy of it and the fact that the list page is better-organised. Since it's a pretty big section, I'd like to get some consensus before I remove the table. Does anyone else think removing the table is a good idea? jgp 04:29, 30 May 2006 (UTC)
 * The table here looks provides an easier look at the processors without having to look at all of the individual speed bumps. It is quite redundant, but I think the smaller table here will give the reader a better look at the Pentium 4 upgrades, rather than looking through the other page. —Last Avenue [ talk | contributions ] 05:13, 1 June 2006 (UTC)

leave the table alone. —Preceding unsigned comment added by 88.218.27.9 (talk • contribs)
 * why? jgp TC 19:41, 30 August 2006 (UTC)

because the info is useful. if you add them in this article http://en.wikipedia.org/wiki/List_of_Intel_Pentium_4_microprocessors then you can remove it —Preceding unsigned comment added by 88.218.27.9 (talk • contribs)
 * That "info" is a cluttered mess. It's inaccurate and unmaintainable. This is a prose article and only prose descriptions belong here. jgp TC 13:35, 31 August 2006 (UTC)
 * Without going over it with a fine-tooth comb, nothing sticks out as inaccurate. The "only prose" justification, taken literally, is extremely weak; articles like Sun benefit greatly from the summarization of information in a tabular format, and loads of articles use some form of tabular infobox (including processor sockets) to great effect.  I think what you really mean is that it's too much table for a WP article.  And perhaps it really isn't appropriate (though it's a great table, frankly).  But I would suggest you hash this out here instead of just deleting it over and over. —  Aluvus  t/ c  14:32, 31 August 2006 (UTC)

Added: The Pentium 4 introduced new technological advances such as hyper-threading, a feature to make one physical CPU appear as two logical and virtual CPUs. Evidence: Look up hyper-threading on www.techweb.com/encyclopedia

Overclocking
Any idea, who made 4ghz or on laptop, i've heard they released 4ghz but never to the public? also 70% faster comapred to 12% intel, something on main page, what's that

Production dates
I have noticed that there is mention of the Pentium 4 line being retired on July 27, 2006. In the introduction. It was also added to the infobox - this information is not cited. AFAIK Pentium 4 CPUs are still being produced and production of Pentium 4s will not stop until next year. Can anybody confirm the so called 'retirement' of these chips? - MaXim 05:53, 1 November 2006 (UTC) It seems to me that's the day they retired it, but

i added the the date they were retired but it got reverted for some reason--Falcon866 21:59, 6 January 2007 (UTC)
 * Maybe you got reverted because the P4 is still in production ?!? --Denniss 01:19, 7 January 2007 (UTC)

Pentium 4 line being retired on July 27, 2006 then how are they still in production--Falcon866 13:25, 7 January 2007 (UTC)?
 * Not retired yet, surpassed by Core 2 but production lines still live. --Denniss 21:32, 7 January 2007 (UTC)

 * Case closed, the Pentium 4 line is discontinued. I am a computer technition so I would know. Our store is no longer able to get Pentium 4 chips at all. Some of the people here may be confusing the Pentium 4 line with the dual core Pentium D. The Pentium D is still widely avalible as a low end, cost effective dual core solution. The single core Pentium 4 however is not being produced any more. Production on the Pentium 4 chips was halted on July 27, 2006 when the Core 2 line appeared. Jdlowery 03:41, 12 March 2007 (UTC)

 * Please provide a source for the P4 end of production. It was for sure not ended once the Core2 appeared. There are still lots of single core Pentium 4 (Cedar Mill) available, at least in Europe. --Denniss 18:58, 12 March 2007 (UTC)

Fastest one core processor
There are mistakes on this page, the processor 3.8 should beat 2.8 by amd or at least equal, are you sure you have things correct? Can somebody check on this, something's rotten in denmark... And somebody in europe claims they are selling 4ghz laptops? Damn, they should have just made it 4ghz and call it a day.

 * The 4GHz Pentium 4 580 could be preorderd by at least 4 resellers in Germany (for a premium of 1400-1500€, well above the 1000€ Extreme Editions), but none claimed to have them in stock. It was also never official announced by Intel. There were however samples distributed to hardwaretest-sites. I remember one test on tomshardware.de (.com probably as well) that introduced the 580 and the 3,73EE. The 580 finished with noticeable more performance, so it should qualify as fastest single-core modell ever produced (though not marketed) in multithreaded or SSE heavy benchmarks. (Which would have placed an "ordinary" Pentium 4 above the permium-ExtremeEdition in power and price)
 * Unfortunately, those tests were removed with all other traces of the 580, so these accounts are not referenceable to the standards of wikipedia. However google still finds one News anouncing the listing at various dealers:
 * www.computerbase.de/news/hardware/prozessoren/intel/2005/juli/intel-pentium-4-580-mit-4-ghz-gelistet
 * It also includes a modellnumber (BX80547PG4000E), which is mentioned on various other websites (but got deleted from Intels lists as well, as all other traces of the CPU).
 * ruyven_macaran 13:15, 25 October 2010 (UTC) —Preceding unsigned comment added by 188.108.182.107 (talk)

Prescott section
The Prescott section has grammar errors and is hard to read. (Anon).

I have heard that the Prescott design reference from Intel specifies a grilled side panel and ducting. Many companies offer such products which are marketed as 'Precott ready', 'Precott compliant', etc. I cannot find the papers about this but if anyone can find them and post them here I'll write it in and try to address the grammar issues raised by Anon above.--ChrisJMoor 21:04, 1 April 2007 (UTC)

I agree, the Prescott section is horrible. Someone has spammed it with blogs (e.g. niche hardware/OC sites) and opinion. To maintain neutrality, it should cite mainstream, respected hardware review sites. And try sticking to the point a bit more. Denniss seems bent on reverting improvements. (Anon). —Preceding unsigned comment added by 134.134.137.71 (talk) 15:20, 5 March 2010 (UTC)

Fair use rationale for Image:Intel Pentium 4 HT.png
Image:Intel Pentium 4 HT.png is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

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If there is other other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images uploaded after 4 May, 2006, and lacking such an explanation will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.BetacommandBot 08:02, 5 June 2007 (UTC)

 * I'm handling it. Suigi 15:44, 5 June 2007 (UTC)

Northwood was faster than Athlon
http://www.computerbase.de/artikel/hardware/prozessoren/2003/test_intel_pentium_4_240c_ghz_athlon_xp_2800/5/ —Preceding unsigned comment added by 134.155.99.42 (talk) 06:24, 27 November 2007 (UTC)

thermal junction
"Pentium 4-M had a thermal junction temperature of 100 degrees, in other words, about 40 degrees more than the desktop Pentium 4" - I don't think this correspondences to the reality. IMHO it should be correct "case temperature" instead of "junction". The junction temperature for semiconductors uses to be much higher - for classical silicium transistors up to 200°C. -- 8ohmSpeaker (talk) 19:17, 29 December 2010 (UTC)

Virtualization at Cedar Mill
"It [Cedar Mill] has a 65 nm core and features ... Virtualization Technology." Is that right? 77.11.112.98 (talk) 05:05, 18 August 2011 (UTC)

the 6th generation processing chips, the way i c it :)
did i say 1000 here: o course i did: only their beeep(the c......n word, sorry) might went wrong then — Preceding unsigned comment added by 93.118.212.93 (talk) 21:41, 25 May 2012 (UTC)

come on, unpack those loops, first make function compounding, bit processing style then aply the info to b processed, use that pipeline n that predication for something get into 6th generation microchips able of evn more than 1000 instr/1T n most important:dont mention me

Florin Matei — Preceding unsigned comment added by 93.118.212.93 (talk) 08:29, 10 March 2012 (UTC) — Preceding unsigned comment added by 93.118.212.93 (talk)

About a possible N->log(N) time optimization

basically, microprocessor instruction r function of 1 bit of 2 binary variables... if that possibly means that any such function, no matter how complex in the background, is formally depending only of 16 variables, then, computer might gain experience that can be useful in n->log(n) time optimizations such as FOR loops especially factorials or PI the most far decimal place known.We assume that we make a difference between the function n the information 2 be processed.

Thank You for Your Time, Florin, Romania — Preceding unsigned comment added by 93.118.212.93 (talk) 07:47, 6 September 2012 (UTC)

Sudden Northwood Death Syndrome (SNDS)
The article mentions that early stepping Northwood cores can suffer from Sudden Northwood Death Syndrome (SNDS).

Which Northwood cores are affected by SNDS? The earlier ones without HT technology (those that run at FSB400 and FSB533)? Or are FSB800 Northwood cores (those with HT technology) also susceptible to SNDS? — Preceding unsigned comment added by 222.165.42.62 (talk) 17:13, 28 June 2012 (UTC)

Class action
There is a class action for certain Intel Pentium 4 processors. Does anyone think this should be included in the article?

http://www.intelpentium4litigation.com/

Printphi (talk) 23:20, 27 October 2014 (UTC)

yes! absolutely! it's the reason someone would want to read about Pentium 4 on wikipedia. Thomas144 (talk) 20:18, 4 November 2014 (UTC)

"Intel eventually added XD Bit (eXecute Disable) and Intel 64 functionality to Prescott"?
Intel 64 or x86-64 is an 64-bit architectural extension, rather than some additional instruction sets, it could not later easily be put onto some a microarchitecture when the number of transistors did not even happen to change obviously. The very first Intel Pentium 4 Prescott processor released in February, 2004, and the very first Pentium 4 Prescott with EM64T released in August, 2004, the same year! Or in other words, Pentium 4 Prescott is just an x86-64 processor, but only enabled with such related functions on select models, rather than later or eventually added such things, they had already presented there, but just disabled. — Preceding unsigned comment added by 221.9.13.186 (talk • contribs) 11:00, 22 May 2017 (UTC)

 * The above seems to be just discussion of the writer's unreferenced claims and assumptions. It is not clear what point you're trying to make, but talk pages are for discussing improvements to the article, and any changes to the article will require references to reliable sources - not your opinions, assumptions, and conclusions therefrom. Jeh (talk) 01:52, 24 May 2017 (UTC)

brand
Pentium 4 is a brand. CPUs branded Pentium 4 were available for a couple of Sockets, and even more important, some Pentium 4-branded CPUs were 32-bit only, while others were 64-bit. User:ScotXW t@lk 12:26, 7 December 2017 (UTC)

title: Talk:Pentium 4


text:
Polaroid Corporation

Polaroid Corporation was an American company best known for its instant film and cameras, which now survives as a brand for consumer electronics. The company was founded in 1937 by Edwin H. Land, to exploit the use of his Polaroid polarizing polymer. Land and Polaroid created the first instant camera, the Land Camera, in 1948.

Land ran the company until 1981. Its peak employment was 21,000 in 1978, and its peak revenue was $3 billion in 1991.

Polaroid Corporation was declared bankrupt in 2001; its brand and assets were sold off. A new Polaroid company formed, and the brand assets changed hands multiple times before being sold to Polish billionaire Wiaczesław Smołokowski in 2017. This acquisition allowed Impossible Project, which had started producing instant films for older Polaroid cameras in 2008, to rebrand as Polaroid Originals in 2017, and eventually as Polaroid in 2020. Since the original company's downfall, Polaroid-branded products in other fields, such as LCD televisions and DVD players, have been developed and released by various licensees globally.

Founding and success

The original Polaroid Corporation was founded in Cambridge, Massachusetts, by Edwin Land and George W. Wheelwright III in 1937. It has been described by The Boston Globe as a "juggernaut of innovation", and "the Apple of its time" with a "leader in Edwin Land, a scientist who guided the company as the founding CEO for four decades". Polaroid’s initial market was in polarized sunglasses — spawned from Land’s self-guided research in light polarization. Land, having completed his freshman year at Harvard University, left to pursue this market, resulting in Polaroid's birth. Land later returned to Harvard to continue his research. Polaroid, owning patents to its polarizer technology, got its start by employing polarization in products that included 3-D movies and protective goggles for military dogs. During World War II, Polaroid designed and manufactured numerous products for the armed services including an infrared night viewing device. He led the company as CEO for 43 years. He headed the Polaroid Corporation, developing it from a small research and marketing firm into a well-known high-tech company. Kodak was a customer for some of Land's polarizing products. Recognized by most as the father of instant photography, he included all the operations of a darkroom inside the film itself. He gave the first public demonstration of his new Land Camera in February 1947; from then until 1972, the user had to release the film manually, pull a tab, and peel the negative from the finished positive print—the first version to eliminate these intermediate steps was the SX-70 of 1972, which ejected the print automatically. Land was pictured on the cover of Life magazine in 1972 with the inscription, "A Genius and His Magic Camera".

In the 1940s, Polaroid purchased the B B Chemical Company building at 784 Memorial Drive in Cambridge, Massachusetts for its headquarters. The landmark Streamline Moderne style structure would be added to the National Register of Historic Places listings in Cambridge, Massachusetts in 1982.

When Kodak announced instant film cameras in 1976, Polaroid announced they were suing them, accusing Kodak of having stolen its patented instant photography process. In the two years that followed the lawsuit, total sales of instant cameras climbed from 7.4 million cameras in 1976 to 10.3 million in 1977 and 14.3 million in 1978. The suit in federal court lasted 10 years. Polaroid asked for $12 billion for infringements of its patents by Kodak. The court ruled in favor of Polaroid and ordered Kodak to cease instant picture production, plus pay Polaroid $909.5 million of the $12 billion it had asked for.

Decline
In 1977, Land introduced the Polaroid Instant Home Movie camera named Polavision, based on the Dufaycolor process. However, the product arrived on the market when videotape-based systems were rapidly gaining popularity. Thus it failed to sell well in retail stores and has been described as the swan song for Polaroid. After four decades as chairman, Edwin Land was coerced into resigning and leaving the corporation he had founded. He died in 1991. The Polavision debacle eventually caused the company to write off $89 million, including most of the manufactured products. The underlying technology of Polavision was later improved for use in the Polachrome instant slide film system.

William J. McCune Jr was appointed chief executive officer in 1980. He joined the company in 1939, two years after its founding. He led the company until end 1985 when I. M. Booth, 54, was appointed as Polaroid’s chief executive, McCune remained chairman.

In the 1980s, Polaroid tried to reinvent itself without Land at its helm by shifting away from a dependence on consumer photography, a market that was in steady decline. In 1984 Polaroid announced "that it would enter the United States electronic video market with its own line of Polaroid videotapes."

Polaroid was forced to make wholesale changes that included having to fire thousands of workers and close many factories. The 1980s saw the advent of new technologies that profoundly changed the world of photography — one-hour color film processing, single-use cameras from competitors, videotape camcorders, and, in the 1990s and 2000s, digital cameras.

The company was in fact one of the early manufacturers of digital cameras, with the PDC-2000 in 1996; however, it failed to capture a large market share in that segment.

It also made 35 mm and multi-format scanners, such as Polaroid SprintScan 4000 35 mm scanner (the first scanner with a 4000 DPI CCD) in 1999, and the Polaroid PrintScan 120 in 2000. The scanners received mixed reviews and saw heavy competition from Nikon and Minolta products. The entire line was discontinued when Polaroid entered bankruptcy in 2001.

Prior to bankruptcy, the company sold its landmark, historic headquarters building and surrounding property to The Bulfinch Companies for $10 million.

Bankruptcy (2001)
The original Polaroid Corporation filed for federal Chapter 11 bankruptcy protection on October 11, 2001. The outcome was that within ten months, most of the business (including the "Polaroid" name itself and non-bankrupt foreign subsidiaries) had been sold to Bank One's One Equity Partners (OEP). OEP Imaging Corporation then changed its name to Polaroid Holding Company (PHC). However, this new company operated using the name of its bankrupt predecessor, Polaroid Corporation.

Significant criticism surrounded this "takeover" because the process left executives of the company with large bonuses, while stockholders, as well as current and retired employees, were left with nothing. The company announced a plan that gave the top 45 executives bonuses just for staying at their jobs. Meanwhile, other employees were restricted from selling their stock before leaving their jobs.

As part of the settlement, the original Polaroid Corporation changed its name to Primary PDC, Inc. Having sold its assets, it was now effectively nothing more than an administrative shell. Primary PDC received approximately 35 percent of the "new" Polaroid, which was to be distributed to its unsecured creditors (including bondholders). , Primary PDC remained in existence under Chapter 11 bankruptcy protection, but conducts no commercial business and has no employees.

Polaroid’s bankruptcy is widely attributed to the failure of senior management — unable to anticipate the impact of digital cameras on its film business. This type of managerial failure is also known as the success trap.

Use of Polaroid brand and assets following bankruptcy
After the bankruptcy, the Polaroid brand was licensed for use on other products with the assistance of Skadden, Arps, Slate, Meagher & Flom. In September 2002, World Wide Licenses, a subsidiary of The Character Group plc, was granted the exclusive rights for three years to manufacture and sell digital cameras under the Polaroid brand for distribution internationally. Polaroid branded LCDs and plasma televisions and portable DVD players had also appeared on the market.

On April 27, 2005, Petters Group Worldwide announced its acquisition of PHC. Petters has in the past bought up failed companies with well-known names for the value of those names. The same year, Flextronics purchased Polaroid's manufacturing operations and the decision was made to send most of the manufacturing to China. It stopped making Polaroid cameras in 2007 and discontinued the sale of Polaroid film after 2009 to the dismay of loyal consumers. On December 18, 2008, the post-reorganization Polaroid Corp. filed for Chapter 11 bankruptcy protection in U.S. Bankruptcy Court for the District of Minnesota. The bankruptcy filing came shortly after the criminal investigation of its parent company, Petters Group Worldwide, and the parent company founder, Tom Petters.

Auction for Polaroid Corporation's assets
On April 2, 2009, Patriarch Partners won an auction for Polaroid Corporation's assets including the company's name, intellectual property, and photography collection. Patriarch's $59.1 million bid beat bids from PHC Acquisitions, Hilco Consumer Capital Corp and Ritchie Capital.

This led to some very contentious fighting and litigation, and Patriarch wound up walking away in early May 2009, and a joint venture between Gordon Brothers Brands LLC and Hilco Consumer Capital LP picked up the pieces. According to a Reuters report:

"The move by New York-based Patriarch, a private-equity firm, [to drop their claim], follows US District Judge James Rosenbaum's ruling on Thursday in Minneapolis that putting the purchase on hold during appeal would threaten operations at Polaroid, which is spending its cash at a rate of $3 million a month."

On April 16, 2009, Polaroid won US Bankruptcy Court approval to be sold to a joint venture of Hilco Consumer Capital LP of Toronto and Gordon Brothers Brands LLC of Boston.

Hilco Consumer Capital and Gordon Brothers Brands announced the closing of the purchase of Polaroid Corporation on May 7, 2009, placing Polaroid Corporation in joint holding under a parent company named PLR IP Holdings, LLC. Former executive vice president and general manager – Americas, Scott W. Hardy was named as the new president of Polaroid Corporation and PLR IP Holdings, LLC. The majority of employees remained in their positions at the company's Minnetonka, Minnesota headquarters as well as office locations in Boston, New York and Toronto.

On June 19, 2009, the new holding corporation for Polaroid, PLR IP Holdings, LLC announced an exclusive 5-year agreement with Summit Global Group to produce and distribute Polaroid-branded digital still cameras, digital video cameras, digital photo frames and PoGo-branded mobile products. Summit Global Group added several former Polaroid employees to their staff. The company expects the agreement to yield $1.3 billion in retail sales over an unspecified period beginning in 2009.

On January 5, 2010, Polaroid appointed Lady Gaga as "Creative Director" for the company. A press release stated that she would be the "new face" of Polaroid. In a 2014 interview an account supervisor at R&J Public Relations, the PR firm for Polaroid, stated that the company is no longer working with Lady Gaga.

2017-Present: Acquisition by Smołokowski; collaboration with and rebranding of "Impossible"
In 2017, the holding corporation for Polaroid, PLR IP Holdings, LLC, was acquired by Polish investor Wiaczesław "Slava" Smołokowski. Smołokowski was already the largest shareholder in the Impossible Project—a company formed to continue production of Polaroid-compatible film after Polaroid themselves left the market—having been persuaded to invest in it by his son Oskar. The acquisition brought both companies under the control of the Smołokowski family.

The Impossible Project (already led by Oskar Smołokowski) was rebranded as Polaroid Originals, with the last factory producing Polaroid-compatible instant film cartridges in Enschede, Netherlands being rebranded under the new name later in 2017.

In March 2019, the new polaroid.com website listed instant cameras and supplies made by Polaroid Originals alongside its other products including digital cameras, sunglasses, the Cube action camera, and television units.

March 2020, Polaroid Originals rebranded as simply Polaroid, with the Polaroid Now being the first instant film camera in years to have the Polaroid branding.

Efforts to preserve and restore vintage Polaroid camera models
Polaroid B.V. and other companies, including MiNT Camera (manufacturer of the reusable MiNT flash bar), refurbish and repair classic Polaroid products, with some companies modifying the hardware itself to add additional functionality. One such modification is the conversion of Polaroid SX-70 camera models to use the more common, and higher-ISO Polaroid 600 film.

Controversy
In 1970, Caroline Hunter and her co-worker, future husband Ken Williams, discovered the involvement of their employer, Polaroid, in the South African apartheid system as the producer of the passbook photos used to identify Black individuals in South Africa. To pressure Polaroid to divest from South Africa, Hunter and Williams created the Polaroid Revolutionary Worker Movement (PRWM). Through the PRWM, Hunter and Williams organized a boycott against the corporation. Consequently, Polaroid banned all sales to the government, including the military and police, and promised to raise wages and increase job training at its distributors. The plan did not pacify the PRWM, however, and, in 1971, Hunter testified before the United Nations advocating a boycott of Polaroid products. Polaroid proceeded to fire both Hunter and Williams. As a result of protests, a community group in Boston donated $10,000 it received from Polaroid to South African liberation movements. In 1977, it became public Polaroid film was being sold by the distributor Frank and Hirsch to the South African government for use in the "passbook" in violation of Polaroid's policy. This ended Polaroid's relationship with its distributor and all direct sales to South Africa.

(diskettes)
In 1985, Polaroid had its own brand of $5 1/4$-inch floppy disks, and also a data recovery service. In 1987, The New York Times described it as a major brand. In 1985, The New York Times listed it a notch lower in an almost reverse alphabetical list,  and noted "remember that those companies established their reputations by selling other products, not diskettes."

By mid 1991, they stopped selling floppy disks. The packaging used both Polaroid and PerfectData brands

Corporate sponsorship of motorsports
In the 1990s, Polaroid was involved in corporate sponsorship of NASCAR. For several years, Polaroid was the principal sponsor of NASCAR's 125 mile Featherlite Modified race at Watkins Glen and it was called the "Polaroid 125". The Polaroid name was also used in sponsorship in the NASCAR Busch Series. In 1992, Polaroid was the principal sponsor of female NASCAR driver Shawna Robinson's #25 Oldsmobile in the Busch Series. They continued as her principal sponsor when she moved to the other car numbers in 1993 and 1994.

Polaroid formerly sponsored the Target Chip Ganassi entry of Juan Pablo Montoya's #42 Chevy Impala in the NASCAR Sprint Cup Series and entries in the IRL Indy Car Series, including the car driven by Dario Franchitti.

The Polaroid name has also been associated with the NOPI drift series. Polaroid was the principal sponsor of the Nissan 350Z driven by Nick Bollea in the 2007 season.

Discontinuation and relaunch of Polaroid film
On February 8, 2008, Polaroid (under the control of Thomas J. Petters of Petters Group Worldwide) announced that the company has decided to gradually cease production and withdraw from analog instant film products completely in 2008. Since March 2010, instant film materials for vintage Polaroid cameras have again become available on the market, developed and manufactured by a group called The Impossible Project, at the former Polaroid production plant in Enschede, Netherlands.

Austrian photographer Florian Kaps, the owner of the largest online vendor for SX-70 films and organizer of the web-based instant photo gallery Polanoid.net, had bought the approximately 500,000 film packages that were on stock. He teamed with André Bosman, a former head of film production in the large Polaroid film factory at Enschede, designed a plan to redesign the SX-70/600 film system in collaboration with Ilford Photo, and convinced the Polaroid owners to participate. Plans for a relaunch under the Impossible label were announced in January 2009. Buildings in the Enschede plant, which had produced 30 million film packs in 2007 and 24 million in the first half of 2008, were leased to the company created by Kaps, who by May 2009 had raised $2.6 million from friends and family for what he had named The Impossible Project.

On March 22, 2010, Impossible announced the release of two monochromatic films, PX100 and PX600, compatible with SX-70 and 600 type cameras, respectively. Color films were initially released in 2010 for SX-70 type cameras, followed in 2011 with the release of much improved color films for Polaroid 600, SX-70 and Spectra Cameras.

Then Impossible had originally announced a new camera that was going to be styled after older Polaroid models to coincide with the new film. The camera was due to come out before Christmas 2010, but the deadline passed with no new information on the camera. In April 2016, Impossible released the Impossible I-1; however, it was not styled after older Polaroid cameras. It was the first camera to use I-type Film and was backwards compatible with 600 Film due to I-type film being 600 film without a battery. After rebranding to Polaroid Originals, the company released another camera in September 2017 called the OneStep 2. This camera was modeled after the original OneStep with new features as originally planned, though the OneStep 2 uses the same type of film as the Impossible I-1 unlike the OneStep that used SX-70 Film.

On April 28, 2012, the documentary "Time Zero: The Last Year of Polaroid Film", directed by Grant Hamilton, was released in the U.S. It covers the rise, fall, and grass-roots revival of Polaroid's instant film technology.

Mobile printers
In summer 2008 Polaroid released the PoGo, an instant photo printer producing 2 x prints. It uses the Zink ("zero ink") technology which is similar to dye sublimation but has the dye crystals embedded in the photo paper itself. Models CZA-10011B and CZA-20011B exist (which Polaroid claim to be identical).

In 2009, the CZA-05300B PoGo, a 5 megapixel digital camera integrated with a Zink printer, was released.

In 2011, the company released the Polaroid GL10 Instant Mobile Printer producing 3 by 4 inch prints. The printer, designed by Polaroid and Lady Gaga, allows people to print directly from a mobile phone or digital camera. This product is the first product in the new Polaroid Grey Label line.

Digital photography
Polaroid released a line of cameras without printers including the t1035, a 10-megapixel digital camera.

In January 2012, Polaroid announced a new "smart camera", entitled the Polaroid SC1630 smart camera, which is powered by Google Android. The SC1630 is a combination of a camera and a portable media player, that allows users to take photos with a built-in 16 MP HD camera, download apps from Google Play, check their email, and browse the web. The built-in camera allows 3X optical zoom. Other features on the media player include Wi-Fi, touch screen, geotagging, smart albums, and 32 GB of storage via a micro SD card.

In September 2014 Polaroid introduced a $99 action camera named the "Polaroid Cube", marketed as an alternative to cameras such as the GoPro Hero (which retails for $129), specifically for casual, light users of action camcorders. In 2015 GoPro released the similar GoPro HERO4 Session.

Wideblue
In March 2006, the specialist design and development department in Polaroid's Vale of Leven plant in Scotland was bought out by its management team. Known as Wideblue the company specializes in helping small technology based companies develop products and manufacturing processes.

In 2014 Wideblue was hired to design the Impossible Project mass market instant camera.

Official websites

 * Polaroid Eyewear
 * The Polaroid Cube
 * The Polaroid Cube

Spinoffs

 * Wideblue – former specialist design and development department at Vale of Leven plant

Articles

 * Analysis of the Polaroid bankruptcy (cfo.com) – includes discussion of the role of Polaroid executives in the bankruptcy proceedings.
 * Polaroid & Corporate Bankruptcy statement – by U.S. congressman, Bill Delahunt.
 * The Branding of Polaroid – Paul Giambarba on Polaroid's branding, including background information on the company.
 * Polaroid shutting 2 Mass. facilities, laying off 150, The Boston Globe, 2008-02-08, history and future of the company after ceasing its manufacturing of instant film technology.
 * Polaroid shutting 2 Mass. facilities, laying off 150, The Boston Globe, 2008-02-08, history and future of the company after ceasing its manufacturing of instant film technology.

Archives and records

 * Polaroid Revolutionary Workers Movement at the African Activist Archive Project – Material associated with protests against Polaroid's association with apartheid-era South Africa
 * Polaroid Corporation Administrative records at Baker Library Special Collections, Harvard Business School
 * Polaroid Corporation Legal and Patent records at Baker Library Special Collections, Harvard Business School
 * Polaroid Corporation Research and Development records at Baker Library Special Collections, Harvard Business School
 * Polaroid Corporation Records Related to Edwin H. Land at Baker Library Special Collections, Harvard Business School
 * Polaroid Corporation Audiovisual records at Baker Library Special Collections, Harvard Business School
 * Polaroid Corporation Records Related to Meroe Morse at Baker Library Special Collections, Harvard Business School

title: Polaroid Corporation


text:
Well-posed problem

In mathematics, a well-posed problem is one for which the following properties hold:
 * 1) The problem has a solution
 * 2) The solution is unique
 * 3) The solution's behavior changes continuously with the initial conditions

Examples of archetypal well-posed problems include the Dirichlet problem for Laplace's equation, and the heat equation with specified initial conditions. These might be regarded as 'natural' problems in that there are physical processes modelled by these problems.

Problems that are not well-posed in the sense above are termed ill-posed. Inverse problems are often ill-posed; for example, the inverse heat equation, deducing a previous distribution of temperature from final data, is not well-posed in that the solution is highly sensitive to changes in the final data.

Continuum models must often be discretized in order to obtain a numerical solution. While solutions may be continuous with respect to the initial conditions, they may suffer from numerical instability when solved with finite precision, or with errors in the data.

Conditioning
Even if a problem is well-posed, it may still be ill-conditioned, meaning that a small error in the initial data can result in much larger errors in the answers. Problems in nonlinear complex systems (so-called chaotic systems) provide well-known examples of instability. An ill-conditioned problem is indicated by a large condition number.

If the problem is well-posed, then it stands a good chance of solution on a computer using a stable algorithm. If it is not well-posed, it needs to be re-formulated for numerical treatment. Typically this involves including additional assumptions, such as smoothness of solution. This process is known as regularization. Tikhonov regularization is one of the most commonly used for regularization of linear ill-posed problems.

Energy method
The energy method is useful for establishing both uniqueness and continuity with respect to initial conditions (i.e. it does not establish existence). The method is based upon deriving an upper bound of an energy-like functional for a given problem.

Example: Consider the diffusion equation on the unit interval with homogeneous Dirichlet boundary conditions and suitable initial data $$f(x)$$ (e.g. for which $$f(0)=f(1)=0$$).

$$	\begin{align} u_t&=D u_{xx}, && 00,\, D>0,\\ u(x,0)&=f(x),\\ u(0,t)&=0,\\ u(1,t)&=0,\\ \end{align} $$

Multiply the equation $$u_t=D u_{xx}$$ by $$u$$ and integrate in space over the unit interval to obtain

$$\begin{align} &&\int_0^1 uu_t dx&=D\int_0^1 uu_{xx}dx \\\Longrightarrow &&\int_0^1 \frac{1}{2}\partial_t u^2 dx&=Duu_x\Big|_0^1-D\int_0^1(u_x)^2dx \\\Longrightarrow &&\frac{1}{2} \partial_t\|u\|_2^2&=0-D\int_0^1(u_x)^2dx\leq 0 \end{align}$$

This tells us that $$\|u\|_2$$ (p-norm) cannot grow in time. By multiplying by two and integrating in time, from $$0$$ up to $$t$$, one finds

$$\|u(\cdot,t)\|_2^2 \leq \|f(\cdot)\|_2^2$$

This result is the energy estimate for this problem.

To show uniqueness of solutions, assume there are two distinct solutions to the problem, call them $$u$$ and $$v$$, each satisfying the same initial data. Upon defining $$w=u-v$$ then, via the linearity of the equations, one finds that $$w$$ satisfies

$$	\begin{align} w_t&=D w_{xx}, &&00,\, D>0,\\ w(x,0)&=0,\\ w(0,t)&=0,\\ w(1,t)&=0,\\ \end{align} $$

Applying the energy estimate tells us $$\|w(\cdot,t)\|_2^2 \leq 0$$ which implies $$u=v$$ (almost everywhere).

Similarly, to show continuity with respect to initial conditions, assume that $$u$$ and $$v$$ are solutions corresponding to different initial data $$u(x,0)=f(x)$$ and $$v(x,0)=g(x)$$. Considering $$w=u-v$$ once more, one finds that $$w$$ satisfies the same equations as above but with $$w(x,0)=f(x)-g(x)$$. This leads to the energy estimate $$\|w(\cdot,t)\|_2^2 \leq D\|f(\cdot)-g(\cdot)\|_2^2$$ which establishes continuity (i.e. as $$f$$ and $$g$$ become closer, as measured by the $$L^2$$ norm of their difference, then $$\|w(\cdot,t)\|_2 \to 0$$).

The maximum principle is an alternative approach to establish uniqueness and continuity of solutions with respect to initial conditions for this example. The existence of solutions to this problem can be established using Fourier series.

title: Well-posed problem


text:
User:Rahul~enwiki

Rahul.

title: User:Rahul~enwiki