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Oliver Hazard Perry

Oliver Hazard Perry (August 23, 1785 – August 23, 1819) was an American naval commander, born in South Kingstown, Rhode Island. A prominent member of the Perry family naval dynasty, he was the son of Sarah Wallace Alexander and United States Navy Captain Christopher Raymond Perry, and older brother of Commodore Matthew C. Perry.

Perry served in the West Indies during the Quasi War of 1798–1800 against France, in the Mediterranean during the Barbary Wars of 1801–1815, and in the Caribbean fighting piracy and the slave trade, but is most noted for his role in the War of 1812 during the 1813 Battle of Lake Erie. During the war against Britain, Perry supervised the building of a fleet at Erie, Pennsylvania. He earned the title "Hero of Lake Erie" for leading American forces in a decisive naval victory at the Battle of Lake Erie, receiving a Congressional Gold Medal and the Thanks of Congress.

His leadership materially aided the successful outcomes of all nine Lake Erie military campaign victories, and the victory was a turning point in the battle for the west in the war. He is remembered for the words on his battle flag, "Don't Give Up the Ship", which was a tribute to the dying command of his colleague Captain James Lawrence of USS Chesapeake. He is also known for his message to General William Henry Harrison which reads in part, "We have met the enemy and they are ours; ..."

Perry became embroiled in a long-standing and bitter controversy with the commander of USS Niagara (1813), Captain Jesse Elliott, over their conduct in the Battle of Lake Erie, and both were the subject of official charges. In 1815, he successfully commanded USS Java (1815) in the Mediterranean during the Second Barbary War. So seminal was his career that he was lionized in the press (being the subject of scores of books and articles). He has been frequently memorialized, and many places, ships and persons have been named in his honor.

Childhood and early life
Perry was the oldest of five boys born to Christopher (1761–1818) and Sarah Wallace Perry (née Alexander) (1763–1830). As a boy, Perry lived in Tower Hill, Rhode Island, sailing ships in anticipation of his future career as an officer in the United States Navy. Perry came from a long line of naval men from both sides of his family. His mother taught Perry and his younger brothers to read and write and had them attend Trinity Episcopal Church regularly, where he was baptized by Reverend William Smith on April 1, 1794, at the age of nine. Reverend Theodore Dehon, rector of the church from 1797 to 1810, had a significant influence on the young Perry. He was educated in Newport, Rhode Island. His earliest ancestor to the Americas was Edward Perry, who came from Devon, England, and settled in Sandwich, Massachusetts, around 1650 with his wife, Mary Freeman.

Early naval career
Through his father's influence, Perry was appointed a midshipman in the United States Navy, at the age of thirteen, on April 7, 1799. Perry sailed aboard USS General Greene (1799), of which his father was commanding officer, on her maiden voyage in June 1799. The ship made its first stop in Cuba, charged with receiving American merchant ships and providing escort from Havana to the United States. Perry's service aboard General Greene continued during the Quasi-War with France. He first experienced combat on February 9, 1800, off the coast of the French colony of Haiti, which was in a state of rebellion.

During the First Barbary War, he served aboard USS Adams (1799) and later was first lieutenant (second in command) of USS Nautilus (1799). He then served under Captain John Rodgers on USS Constitution and USS Essex. He was placed in charge of the construction of gunboats in Newport and Westerly, Rhode Island.

Beginning in April 1809, he commanded the sloop USS Revenge (1806), engaging in patrol duties to enforce the Embargo Act, as well as a successful raid to regain an American ship held in Spanish territory in Florida. On January 9, 1811, Revenge ran aground off Rhode Island and was lost. "Seeing fairly quickly that he could not save the vessel, [Perry] turned his attention to saving the crew, and after helping them down the ropes over the vessel's stern, he was the last to leave the vessel." The subsequent court-martial exonerated Perry, placing blame on the ship's pilot. In January 2011, a team of divers claimed to have discovered the remains of Revenge, nearly 200 years to the day after it sank. Cannons from Revenge were salvaged by the U.S. Navy in 2017.

Following the court-martial, Perry was given a leave of absence from the Navy. On May 5, 1811, he married Elizabeth Champlin Mason of Newport, Rhode Island, whom he had met at a dance in 1807. They enjoyed an extended honeymoon touring New England. The couple would eventually have five children, with one dying in infancy.

War of 1812
At the beginning of the War of 1812, the British Royal Navy controlled the Great Lakes, except for Lake Huron. The United States Navy controlled Lake Champlain. The American naval forces were very small, allowing the British to make many advances in the Great Lakes and northern New York waterways. The roles played by commanders like Perry, at Lake Erie and Isaac Chauncey at Lake Ontario and Thomas Macdonough at Lake Champlain all proved vital to the naval effort.

Naval historian E. B. Potter noted that "all naval officers of the day made a special study of Nelson's battles". Oliver Perry was no exception. At his request, he was given command of the American naval forces on Lake Erie during the war. Secretary of the Navy Paul Hamilton had charged prominent merchant seaman Daniel Dobbins with building the American fleet on Presque Isle Bay at Erie, Pennsylvania, and Perry was named chief naval officer.

Perry knew battle was coming, and he "consciously followed Nelson's example in describing his battle plans to his captains." Perry's instructions were:

"Commanding officers are particularly enjoined to pay attention in preserving their stations in the Line, and in all cases to keep as near the Lawrence as possible. ... Engage your designated adversary, in close action, at half cable's length."

Hero of Lake Erie

On September 10, 1813, Perry's command fought a successful fleet action against a squadron of the Royal Navy in the Battle of Lake Erie. It was at the outset of this battle that Perry famously said, "If a victory is to be gained, I will gain it." Initially, the exchange of gunfire favored the British. Perry's flagship, USS Lawrence (1813), was so severely disabled in the encounter that the British commander, Robert Heriot Barclay, thought that Perry would surrender it, and sent a small boat to request that the American vessel pull down its flag.

Faithful to the words of his battle flag, "DON'T GIVE UP THE SHIP", a paraphrase of the dying words of Captain James Lawrence, the ship's namesake and Perry's friend, Perry, with Lawrence's chaplain and purser as the remaining able crew, personally fired the final salvo. He then had his men row him a half-mile (0.8 km) through heavy gunfire to transfer his command to USS Niagara (1813). Once aboard, Perry dispatched Niagara commander, Captain Jesse Elliott, to bring the other schooners into closer action while he steered Niagara toward the damaged British ships. Like Nelson's HMS Victory at Trafalgar, Niagara broke the opposing line.

Perry's force pounded Barclay's ships until they could offer no effective resistance and surrendered. Although he had won the battle aboard Niagara, he received the British surrender on the deck of the recaptured Lawrence to allow the British to see the terrible price his men had paid. Perry's battle report to General William Henry Harrison was famously brief: "We have met the enemy and they are ours; two ships, two brigs, one schooner and one sloop."

This was the first time in history that an entire British naval squadron had surrendered. Every captured ship was successfully returned to Presque Isle.

Although the engagement was small compared to Napoleonic naval battles such as the Battle of Trafalgar, the victory had disproportionate strategic importance, opening Canada up to possible invasion, while simultaneously protecting the entire Ohio Valley. The loss of the British squadron directly led to the critical Battle of the Thames, the rout of British forces by Harrison's army, the deaths of Tecumseh and Roundhead, and the breakup of his Indian alliance. Along with the Battle of Plattsburgh, it was one of only two significant fleet victories of the war.

Perry was involved in nine battles that led to and followed the Battle of Lake Erie, and they all had a seminal impact. "What is often overlooked when studying Perry is how his physical participation and brilliant strategic leadership influenced the outcomes of all nine Lake Erie military campaign victories:

"Capturing Fort George, Ontario in the Battle of Fort George; Destroying the British munitions at Olde Fort Erie (see Capture of Fort Erie); Rescuing five vessels from Black Rock; Building the Erie fleet; Getting the ships over the sandbar; Blocking British supplies for a month prior to battle; Planning the Thames invasion with General Harrison; Winning the Battle of Lake Erie; and Winning the Battle of Thames."

The Battle Flag
"Don't give up the ship!" became the battle cry of Oliver Hazard Perry. The phrase was uttered by Captain James Lawrence as he died after being wounded by enemy fire aboard the Chesapeake on June 1, 1813. Perry learned of Lawrence's demise at Presque Isle. He honored Lawrence with the name of a brig, called Lawrence. A battle flag was needed, and the words of Perry's good friend were suited for the coming days.

A woman named Margaret Forster Steuart was enlisted to make the battle flag. She was a resident of Erie Pennsylvania, wife of Army Captain Thomas Steuart and sister to Thomas Forster, both friends of Perry's. Forster was the commander of the Erie Light Infantry that had guarded the fleet. With the help of her two daughters, three nieces, and a cousin, she had the flag ready for Perry within just a few days. As of July 2009, Perry's flag, Steuart's work, and Lawrence's dying words can be seen today, with the flag on display in Bancroft Hall at the U.S. Naval Academy in Annapolis.

Perry–Elliott controversy
While Nelson had Collingwood, Perry had Jesse Elliott, and was considerably less well served. Elliott, while serving with Isaac Chauncey at Lake Ontario, was tasked to augment Perry's squadron with 11 officers and 91 men, "and none were sent but the worst." Subsequently, detailed by Chauncey to command Niagara, Elliott stated "that if he could have foreseen that he himself should be sent to Lake Erie, his selections would have been different." Elliott then appropriated the "best of the worst" for Niagara; and Perry "in the interest of harmony" accepted the situation, though with growing ill-will.

In his initial post-action report, Perry had praised Captain Elliott's role in the American victory at Lake Erie; and as news of the battle spread, Perry and Elliott were both celebrated as national heroes. Soon after, however, several junior officers publicly criticized Elliott's performance during the battle, charging that Elliott allowed Lawrence to suffer the brunt of the British fire while holding Niagara back from the fight. William Vigneron Taylor, Perry's sailing master, in a letter to Taylor's wife, put it thus:

"The Lawrence alone rec'd the fire of the whole British squadron 2 1/2 hours within pistol shot—we were not supported as we ought to have been. Captain Perry led the Lawrence into action & sustained the most destructive fire with the most gallant spirit perhaps that was ever witnessed under similar circumstances."

The meeting between Elliott and Perry on the deck of Niagara was terse. Elliott inquired how the day was going. Perry replied, "Badly." Elliott then volunteered to take Perry's small boat and rally the schooners, and Perry acquiesced. As Perry turned Niagara into the battle, Elliott was not aboard. Elliott's rejoinder to history's criticism of inaction was that there had been a lack of effective signaling. Charges were filed, but not officially acted upon. Attempting to restore his honor, Elliott and his supporters began a 30-year campaign that would outlive both men and ultimately leave his reputation in tatters.

In Perry's report to Secretary of the Navy William Jones, written three days after the battle, he mentioned Elliott in what, at first, seem to be complimentary terms, but, when read carefully, betray his disdain for Elliott. Perry wrote, "In this action he evinced his characteristic bravery and judgement; and, since the close of the action, has given me the most able and essential assistance."

Congressional Gold Medal
On January 6, 1814, Perry was honored with a Congressional Gold Medal, the Thanks of Congress, and a promotion to the rank of Captain. This was one of 27 Gold Medals authorized by Congress arising from the War of 1812.

 * Obverse – bust of Perry facing right surrounded by Oliverus H. Perry Princeps Stagno Eriense. ~ Classam Totam Contudit.
 * Reverse depicts a sea battle scene with inscriptions:
 * Viam Invenit Virtus Aut Facit
 * Inter Class. Ameri.
 * Et Brit Die X. Sep.
 * MDCCCXIII
 * (Valor finds or makes a way. Between the Fleets of America and Britain September 10, 1813.)

Elliott was also recognized with a Congressional Gold Medal and the Thanks of Congress for his actions in the battle. This recognition would prove to fan the flames of resentment on both sides of the Elliott–Perry controversy.

In recognition of his victory at Lake Erie, in 1813 Perry was elected as an honorary member of the New York Society of the Cincinnati.

Later commands and controversies

In May 1814, Perry took command of a squadron of seven gunboats based in Newport. He held this command for only two months as in July he was placed in command of USS Java (1815), a 44-gun frigate which was under construction in Baltimore. While overseeing the outfitting of Java, Perry participated in the defenses of Baltimore and Washington, D.C., during the British invasion of the Chesapeake Bay. In a twist of irony, these land battles would be the last time the career naval officer saw combat. The Treaty of Ghent was signed before Java could be put to sea.

For Perry, the post-war years were marred by controversies. In 1815, he commanded Java in the Mediterranean during the Second Barbary War. While moored in Naples, Perry slapped the commander of the ship's Marines, Captain John Heath, whom Perry charged with "disrespectful, insolent, and contemptuous conduct to me his superior officer". The ensuing court-martial found both men guilty, but levied only mild reprimands. After the crew returned home, Heath challenged Perry to a pistol duel, which was fought on October 19, 1817, on the same field in Weehawken, New Jersey where Aaron Burr shot and killed Alexander Hamilton. Heath fired first and missed. Perry declined to return fire, satisfying the Marine's honor.

Perry's return from the Mediterranean also reignited the feud with Elliott. After an exchange of angry letters, Elliott challenged Perry to a duel, which Perry refused. (While it was normally considered cowardly to refuse a duel, Perry's stature as a hero was such that no one doubted his physical courage and few felt that Perry had wrongly offended Elliott's honor.) He instead, on August 8, 1818, filed formal court-martial charges against Elliott. Perry filed a total of six charges and twenty-one specifications including "conduct unbecoming an officer," and failure to "do his utmost to take or destroy the vessel of the enemy which it was his duty to encounter."

Wishing to avoid a scandal between two decorated naval heroes, Secretary of the Navy Smith Thompson and President James Monroe suppressed the matter by offering Perry a diplomatic mission to South America in exchange for dropping his charges. This put an official end to the controversy, though it would continue to be debated for another quarter century.

Mission to Venezuela and death
In 1818 Perry purchased a large house on Washington Square in Newport which was built in 1750 for merchant Peter Buloid. The house remained in the Perry family until 1865 and now serves as an antique bookstore.

In 1819, Perry sailed for the Orinoco River, Venezuela, aboard of the frigate USS John Adams (1799) with the frigate USS Constellation (1797) and the schooner USS Nonsuch (1813), arriving on July 15 to discourage piracy, while still maintaining friendly relations with Republic of Venezuela and the Republic of Buenos Aires. Shifting his flag to USS Nonsuch, due to its shallower draft, Perry sailed upriver to Angostura to negotiate an anti-piracy agreement with President Simón Bolívar. A favorable treaty was signed on August 11 with Vice-President Francisco Antonio Zea in the absence of Bolivar (who was engaged in the liberation of New Granada), but when the schooner started downriver, many of her crew, including Perry, had been stricken with yellow fever.

Despite the crew's efforts to reach Trinidad for medical assistance, the commodore died on board USS Nonsuch on August 23, 1819, his 34th birthday, as the ship entered the Gulf of Paria and was nearing Port of Spain. He was buried in Port of Spain with great honors while the Nonsuch's crew acted as honor guard.

His remains were later taken back to the United States in 1826 and interred in Newport, Rhode Island. Originally interred in the Old Common Burial Ground, his body was eventually moved to Newport's Island Cemetery.

Perry Street in Savannah, Georgia, is named in his honor.

Family

Perry married Elizabeth Champlin Mason in 1811. They had five children, four of whom lived to maturity. They were:

 * 1) Brigadier General Christopher Grant Champlin Perry, RIM (April 2, 1812 – April 5, 1854), commander of the Artillery Company of Newport from 1845–1854, m. Murial Frances Sergeant of Philadelphia (great-granddaughter of Benjamin Franklin); their daughter Margaret Mason Perry married the artist John LaFarge;
 * 2) Oliver Hazard Perry II (February 23, 1813 – March 4, 1814), died in infancy;
 * 3) Lieutenant Oliver Hazard Perry, Jr., USN (February 23, 1815 – August 20, 1878), m. 1) Elizabeth Ann Randolph (1816–1847) (Virginia Randolph family) and m. 2) Mary Ann Moseley;
 * 4) First Lieutenant Christopher Raymond Perry, USA (June 29, 1816 – October 8, 1848), never married;
 * 5) Elizabeth Mason Perry, m., as his 2nd wife, the Reverend Francis Vinton, rector of Trinity Episcopal Church in Newport.

Perry's son Christopher Grant Champlin Perry was a physician, and served as commander of the Artillery Company of Newport from April 1848 until his death in 1854. In May 1849 he was commissioned as a brigadier general in the Rhode Island Militia and given command of the 1st Brigade encompassing Newport and Bristol Counties.

Perry's son Oliver Hazard Perry, Jr. entered the Navy as a midshipman in 1829, rose to the rank of lieutenant and resigned in 1849. He served on the United States Exploring Expedition under Captain Charles Wilkes from 1839 to 1842. Although he is buried in the same cemetery as his parents, for unknown reasons, he is not buried in the same plot with his parents.

Perry's son Christopher Raymond Perry graduated from the United States Military Academy at West Point in 1842. He served during the Mexican War and fought at the Battle of Palo Alto on May 8, 1846, and at the Battle of Resaca-de‑la‑Palma on May 9, 1846. He died on active duty as a 1st lieutenant in 1848.

Dates of rank

 * Midshipman – April 7, 1799
 * Lieutenant – January 15, 1807
 * Master Commandant – August 28, 1812
 * Captain – September 10, 1813

Although Perry is often referred to as "Commodore Perry," it should be kept in mind that, prior to the American Civil War, commodore was not a rank in the U.S. Navy but, rather, the title of an officer in command of a squadron of two or more ships. Perry first held the title of commodore when he took command of the Lake Erie squadron in 1813.

Assignments

 * Midshipman, USS General Greene – April 1799 to May 1801
 * Acting Lieutenant, USS Adams – June 1802 to November 1803
 * Second Lieutenant, USS Constellation – May 1804 to July 1805
 * First Lieutenant, USS Nautilus – July 1805 to December 1805
 * Acting Lieutenant, USS Constitution – December 1805 to c. July 1806
 * Second Lieutenant, USS Essex – c. July 1806 to c. October 1806
 * Officer in Charge of Gunboat construction in Newport and Westerly, RI – October 1806 to April 1809
 * Commanding Officer, USS Revenge – April 1809 to January 1811
 * Commanding Officer, Gunboat Squadron, Newport, RI – c. 1811 to January 1813
 * Commanding Officer, Lake Erie Squadron – March 1813 to c. October 1813
 * Commanding Officer, Gunboat squadron, Newport, RI – May 1814 to July 1814
 * Commanding Officer, USS Java (under construction) – July 1814 to August 1815
 * Commanding Officer, USS Java (in commission) – August 1815 to c. May 1817
 * Senior Naval Officer, Newport, RI – c. May 1817 to May 1819
 * Commanding Officer, Venezuelan diplomatic mission – June 1819 to August 1819 (deceased)

Note – Time gaps between assignments were probably in a "waiting orders" status.

Geographical namesakes
Many locations in the United States are named in his honor, including:
 * Perry Traditional Academy, Pittsburgh, PA
 * Perrysville Avenue (Old Rt. 19 connection), Pittsburgh, PA
 * Perry North (Observatory Hill) and Perry South (Perry Hilltop) neighborhoods on the Northside section in the city of Pittsburgh, PA
 * Oliver Hazard Perry Elementary School, Cleveland, OH
 * Perry Elementary School, Erie, PA
 * Commodore Perry School District, including Perry Township, Mercer County, Pennsylvania
 * Oliver Hazard Perry Middle School, Providence, RI
 * Oliver Hazard Perry Elementary School, San Diego, CA
 * Training Ship Oliver Hazard Perry, Newport, RI
 * All of the ten Perry counties in the U.S.
 * Perryville and Perry County, Missouri
 * The hamlet of Perrysburg and the surrounding township; and the Village of Perry, New York and the surrounding township,
 * The city of Perry, Michigan in Perry Township
 * The city of Perry, Georgia
 * The town of Perry, Maine
 * The village of Perry, Illinois
 * The cities of Perrysburg, Perrysville, North Perry and Perry; Perrysburg Township; and Perry County, Ohio.
 * The unincorporated hamlet of South Perry, in Perry Township, Hocking County, Ohio.
 * Perry Township, between Canton and Massillon in Stark County, Ohio. The local high school is also named in his honor.
 * The borough of Perryopolis and Oliver Township, within Perry County, and Oliver Township and Perry Township in Jefferson County, Pennsylvania.
 * The village of Perryville in the town of South Kingstown, Rhode Island. The portion of U.S. Route 1 near Perryville is named the Commodore Oliver Hazard Perry Highway. Perry Street in Newport is also named after him.
 * The City of Hazard in Perry County, Kentucky.
 * Perry County, Tennessee
 * Perry Street, New York
 * Fort Perry in Box Springs, Georgia
 * Commodore Downs Thoroughbred race track in Fairview Township on the western edge of Erie, Pennsylvania (1973-1983).
 * The Inn at Perry Cabin, St. Michaels, Maryland
 * An eastbound service plaza along the Ohio Turnpike is named the Commodore Perry Service Plaza, located in Sandusky County, Ohio.

Monuments
The national monument commemorating Perry is the Perry's Victory and International Peace Memorial at Put-In-Bay, Ohio. Its 352 ft tower, the world's most massive Doric column, was constructed by a multi-state commission between 1912 and 1915.

Other monuments include:
 * Memorial plaque, Trinity Episcopal Church, Newport, Rhode Island, dedicated by Perry's widow on August 23, 1855, the 36th anniversary of his death.
 * Perry Monument, Public Square, Cleveland, Ohio, monument and statue by William Walcutt, dedicated on September 10, 1860, the 47th anniversary of the Battle of Lake Erie. Walcutt's marble statue was replaced with a bronze copy in 1929. The monument was relocated to Fort Huntington Park in 1991.
 * Walcutt's marble Perry statue is on long-term loan to the Perry's Victory and International Peace Memorial.
 * Oliver Hazard Perry by William Greene Turner, Eisenhower Park, Newport, Rhode Island, dedicated September 10, 1885, the 72nd anniversary of the Battle of Lake Erie.
 * Oliver Hazard Perry by Charles Henry Niehaus, Front Park, Buffalo, New York, dedicated on September 25, 1916.
 * Perry Monument, Perry Square, Erie, Pennsylvania, designed by Paul Philippe Cret, 1925, features a bronze copy after William Greene Turner's 1885 statue.
 * Oliver Hazard Perry Memorial Gateway, Port-of-Spain, Trinidad, dedicated April 1925. Captain Henry E. Lackey, the United States Navy representative at the dedication, arrived aboard the newly commissioned light cruiser USS Memphis (CL-13).
 * Perry Monument at Misery Bay, Presque Isle State Park, Erie, Pennsylvania, dedicated in 1926.
 * Oliver Hazard Perry (bronze copy after William Walcutt), on the south front of the Rhode Island State House, Providence, Rhode Island, dedicated in 1928.
 * Perry Monument, Perrysburg, Ohio, dedicated in 1997, features a bronze copy after William Walcutt's 1860 statue.
 * The reverse of the 2013 "Perry's Victory" quarter shows William Walcutt's statue of Perry (1860) with the Perry's Victory and International Peace Memorial in the distance.
 * The family farm in South Kingstown, where Perry was probably born and later built a house, was listed on the National Register of Historic Places in 1982.
 * A larger than life portrait of Commodore Perry hangs in the Executive Chamber of the Rhode Island State House.

Paintings

 * "Commodore Oliver Hazard Perry" (1818–1828) by Gilbert Stuart and Jane Stuart, Toledo Museum of Art, Toledo, Ohio.
 * Perry's Victory on Lake Erie (1865) by William Henry Powell, Rotunda, Ohio Statehouse, Columbus. Dimensions: 12 x.
 * Battle of Lake Erie (1873) by William Henry Powell, United States Capitol, Washington D.C. Dimensions: 16.76 x.
 * Portrait of Oliver Hazard Perry (1900), by Gari Melchers, Executive Chamber, Rhode Island State House.
 * Battle of Lake Erie (c. 1911) by Edward Percy Moran.
 * Battle of Lake Erie, September 10, 1813. (1959) by Charles Robert Patterson and Howard B. French, United States Naval Academy, Annapolis, Maryland.

Documentary
In 2016, principal photography began on We Have Met the Enemy, a feature-length documentary produced by Lou Reda (Vietnam in HD, The Blue and the Gray), for a planned spring 2017 release.

Eponymous ships
Commodore Perry has been repeatedly honored with ships bearing his name.
 * USS Perry (1843), a sailing brig 1843–1865
 * USS Commodore Perry (1859), an armed side-wheel ferry built in 1859 by Stack and Joyce, Williamsburg, New York and purchased by the Navy on October 2, 1861; and commissioned later in the month, Acting Master F. J. Thomas was in command
 * USS Perry (DD-11), a Bainbridge-class destroyer (1900–1919)
 * USS Perry (DD-340), a Clemson-class destroyer converted into a high-speed minesweeper and re-designated DMS–17 effective November 19, 1940. Served 1921–1944; sunk in Battle of Peleliu.
 * SS Oliver Hazard Perry, a Liberty ship. See List of Liberty ships (M–R).
 * USS Perry (DD-844), a Gearing-class destroyer (1945–1970)
 * USS Oliver Hazard Perry (FFG-7), a guided-missile frigate (1976–1997), and the Oliver Hazard Perry-class frigates, of which it was a member, are named in his honor. The Navy built 51 of the Oliver Hazard Perry-class frigates, with the first going into service in 1977, and the last to be finally moth-balled in 2015. See also USS Perry.
 * SSV Oliver Hazard Perry, a Rhode Island Educational Foundation tall ship

Popular Song
In 1820, Anthony Philip Heinrich wrote a song, Ode to the Memory of Commodore O. H. Perry with words by Henry C. Lewis.

title: Oliver Hazard Perry


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Environmental economics

Environmental economics is a sub-field of economics concerned with environmental issues. It has become a widely studied subject due to growing environmental concerns in the twenty-first century. Environmental economics "undertakes theoretical or empirical studies of the economic effects of national or local environmental policies around the world. ... Particular issues include the costs and benefits of alternative environmental policies to deal with air pollution, water quality, toxic substances, solid waste, and global warming."

Environmental economics is distinguished from ecological economics in that ecological economics emphasizes the economy as a subsystem of the ecosystem with its focus upon preserving natural capital. One survey of German economists found that ecological and environmental economics are different schools of economic thought, with ecological economists emphasizing "strong" sustainability and rejecting the proposition that human-made ("physical") capital can substitute for natural capital.

History
The modern field of environmental economics has been traced to the 1960s with significant contribution from Post-Keynesian economist Paul Davidson, who had just completed a management position with the Continental Oil Company.

Market failure
Central to environmental economics is the concept of market failure. Market failure means that markets fail to allocate resources efficiently. As stated by Hanley, Shogren, and White (2007): "A market failure occurs when the market does not allocate scarce resources to generate the greatest social welfare. A wedge exists between what a private person does given market prices and what society might want him or her to do to protect the environment. Such a wedge implies wastefulness or economic inefficiency; resources can be reallocated to make at least one person better off without making anyone else worse off." This results in a inefficient market that needs to be corrected through avenues such as government intervention. Common forms of market failure include externalities, non-excludability and non-rivalry.

Externality
An externality exists when a person makes a choice that affects other people in a way that is not accounted for in the market price. An externality can be positive or negative but is usually associated with negative externalities in environmental economics. For instance, water seepage in residential buildings occurring in upper floors affect the lower floors. Another example concerns how the sale of Amazon timber disregards the amount of carbon dioxide released in the cutting. Or a firm emitting pollution will typically not take into account the costs that its pollution imposes on others. As a result, pollution may occur in excess of the 'socially efficient' level, which is the level that would exist if the market was required to account for the pollution. A classic definition influenced by Kenneth Arrow and James Meade is provided by Heller and Starrett (1976), who define an externality as "a situation in which the private economy lacks sufficient incentives to create a potential market in some good and the nonexistence of this market results in losses of Pareto efficiency". In economic terminology, externalities are examples of market failures, in which the unfettered market does not lead to an efficient outcome.

Common goods and public goods
When it is too costly to exclude some people from access to an environmental resource, the resource is either called a common property resource (when there is rivalry for the resource, such that one person's use of the resource reduces others' opportunity to use the resource) or a public good (when use of the resource is non-rivalrous). In either case of non-exclusion, market allocation is likely to be inefficient.

These challenges have long been recognized. Hardin's (1968) concept of the tragedy of the commons popularized the challenges involved in non-exclusion and common property. "Commons" refers to the environmental asset itself, "common property resource" or "common pool resource" refers to a property right regime that allows for some collective body to devise schemes to exclude others, thereby allowing the capture of future benefit streams; and "open-access" implies no ownership in the sense that property everyone owns nobody owns.

The basic problem is that if people ignore the scarcity value of the commons, they can end up expending too much effort, over harvesting a resource (e.g., a fishery). Hardin theorizes that in the absence of restrictions, users of an open-access resource will use it more than if they had to pay for it and had exclusive rights, leading to environmental degradation. See, however, Ostrom's (1990) work on how people using real common property resources have worked to establish self-governing rules to reduce the risk of the tragedy of the commons.

The mitigation of climate change effects is an example of a public good, where the social benefits are not reflected completely in the market price. Because the personal marginal benefits are less than the social benefits the market under-provides climate change mitigation. This is a public good since the risks of climate change are both non-rival and non-excludable. Such efforts are non-rival since climate mitigation provided to one does not reduce the level of mitigation that anyone else enjoys. They are non-excludable actions as they will have global consequences from which no one can be excluded. A country's incentive to invest in carbon abatement is reduced because it can "free ride" off the efforts of other countries. Over a century ago, Swedish economist Knut Wicksell (1896) first discussed how public goods can be under-provided by the market because people might conceal their preferences for the good, but still enjoy the benefits without paying for them.

Valuation
Assessing the economic value of the environment is a major topic within the field. The values of natural resources often are not reflected in prices that markets set and, in fact, many of them are available at no monetary charge. This mismatch frequently causes distortions in pricing of natural assets: both overuse of them and underinvestment in them. Economic value or tangible benefits of ecosystem services and, more generally, of natural resources, include both use and indirect (see the nature section of ecological economics). Non-use values include existence, option, and bequest values. For example, some people may value the existence of a diverse set of species, regardless of the effect of the loss of a species on ecosystem services. The existence of these species may have an option value, as there may be the possibility of using it for some human purpose. For example, certain plants may be researched for drugs. Individuals may value the ability to leave a pristine environment for their children.

Use and indirect use values can often be inferred from revealed behavior, such as the cost of taking recreational trips or using hedonic methods in which values are estimated based on observed prices. Non-use values are usually estimated using stated preference methods such as contingent valuation or choice modelling. Contingent valuation typically takes the form of surveys in which people are asked how much they would pay to observe and recreate in the environment (willingness to pay) or their willingness to accept (WTA) compensation for the destruction of the environmental good. Hedonic pricing examines the effect the environment has on economic decisions through housing prices, traveling expenses, and payments to visit parks.

State subsidy
Almost all governments and states magnify environmental harm by providing various types of subsidies that have the effect of paying companies and other economic actors more to exploit natural resources than to protect them. The damage to nature of such public subsidies has been conservatively estimated at $4-$6 trillion U.S. dollars per year.

Solutions
Solutions advocated to correct such externalities include:

If companies are allowed to include some of these externalities in their final prices, this could undermine the Jevons paradox and provide enough revenue to help companies innovate.
 * Environmental regulations. Under this plan, the economic impact has to be estimated by the regulator. Usually, this is done using cost–benefit analysis. There is a growing realization that regulations (also known as "command and control" instruments) are not so distinct from economic instruments as is commonly asserted by proponents of environmental economics. E.g.1 regulations are enforced by fines, which operate as a form of tax if pollution rises above the threshold prescribed. E.g.2 pollution must be monitored and laws enforced, whether under a pollution tax regime or a regulatory regime.  The main difference an environmental economist would argue exists between the two methods, however, is the total cost of the regulation.  "Command and control" regulation often applies uniform emissions limits on polluters, even though each firm has different costs for emissions reductions, i.e., some firms, in this system, can abate pollution inexpensively, while others can only abate it at high cost.  Because of this, the total abatement in the system comprises some expensive and some inexpensive efforts.  Consequently, modern "Command and control" regulations are oftentimes designed in a way that addresses these issues by incorporating utility parameters. For instance, CO2 emission standards for specific manufacturers in the automotive industry are either linked to the average vehicle footprint (US system) or average vehicle weight (EU system) of their entire vehicle fleet. Environmental economic regulations find the cheapest emission abatement efforts first, and then move on to the more expensive methods.  E.g. as said earlier, trading, in the quota system, means a firm only abates pollution if doing so would cost less than paying someone else to make the same reduction.  This leads to a lower cost for the total abatement effort as a whole.
 * Quotas on pollution. Often it is advocated that pollution reductions should be achieved by way of tradeable emissions permits, which if freely traded may ensure that reductions in pollution are achieved at least cost. In theory, if such tradeable quotas are allowed, then a firm would reduce its own pollution load only if doing so would cost less than paying someone else to make the same reduction, i.e., only if buying tradeable permits from another firm(s) is costlier. In practice, tradeable permits approaches have had some success, such as the U.S.'s sulphur dioxide trading program or the EU Emissions Trading Scheme, and interest in its application is spreading to other environmental problems.
 * Taxes and tariffs on pollution. Increasing the costs of polluting will discourage polluting, and will provide a "dynamic incentive", that is, the disincentive continues to operate even as pollution levels fall. A pollution tax that reduces pollution to the socially "optimal" level would be set at such a level that pollution occurs only if the benefits to society (for example, in form of greater production) exceeds the costs. This concept was introduced by Arthur Pigou, a British economist active in the late nineteenth through the mid-twentieth century. He showed that these externalities occur when markets fail, meaning they do not naturally produce the socially optimal amount of a good or service. He argued that “a tax on the production of paint would encourage the [polluting] factory to reduce production to the amount best for society as a whole.” These taxes are known amongst economists as Pigouvian Taxes, and they regularly implemented where negative externalities are present. Some advocate a major shift from taxation from income and sales taxes to tax on pollution - the so-called "green tax shift".
 * Better defined property rights. The Coase Theorem states that assigning property rights will lead to an optimal solution, regardless of who receives them, if transaction costs are trivial and the number of parties negotiating is limited. For example, if people living near a factory had a right to clean air and water, or the factory had the right to pollute, then either the factory could pay those affected by the pollution or the people could pay the factory not to pollute. Or, citizens could take action themselves as they would if other property rights were violated. The US River Keepers Law of the 1880s was an early example, giving citizens downstream the right to end pollution upstream themselves if the government itself did not act (an early example of bioregional democracy). Many markets for "pollution rights" have been created in the late twentieth century—see emissions trading. According to the Coase Theorem, the involved parties will bargain with each other, which results in an efficient solution. However, modern economic theory has shown that the presence of asymmetric information may lead to inefficient bargaining outcomes. Specifically, Rob (1989) has shown that pollution claim settlements will not lead to the socially optimal outcome when the individuals that will be affected by pollution have learned private information about their disutility already before the negotiations take place. Goldlücke and Schmitz (2018) have shown that inefficiencies may also result if the parties learn their private information only after the negotiations, provided that the feasible transfer payments are bounded. Using cooperative game theory, Gonzalez, Marciano and Solal (2019) have shown that in social cost problems involving more than three agents, the Coase theorem suffers from many counterexamples and that only two types of property rights lead to an optimal solution.
 * Accounting for environmental externalities in the final price. In fact, the world's largest industries burn about $7.3 trillion of free natural capital per year. Thus, the world's largest industries would hardly be profitable if they had to pay for this destruction of natural capital. Trucost has assessed over 100 direct environmental impacts and condensed them into 6 key environmental performance indicators (EKPIs). The assessment of environmental impacts is derived from different sources (academic journals, governments, studies, etc.) due to the lack of market prices. The table below gives an overview of the 5 regional sectors per EKPI with the highest impact on the overall EKPI:

Relationship to other fields
Environmental economics is related to ecological economics but there are differences. Most environmental economists have been trained as economists. They apply the tools of economics to address environmental problems, many of which are related to so-called market failures—circumstances wherein the "invisible hand" of economics is unreliable. Most ecological economists have been trained as ecologists, but have expanded the scope of their work to consider the impacts of humans and their economic activity on ecological systems and services, and vice versa. This field takes as its premise that economics is a strict subfield of ecology. Ecological economics is sometimes described as taking a more pluralistic approach to environmental problems and focuses more explicitly on long-term environmental sustainability and issues of scale.

Environmental economics is viewed as more idealistic in a price system; ecological economics as more realistic in its attempts to integrate elements outside of the price system as primary arbiters of decisions. These two groups of specialisms sometimes have conflicting views which may be traced to the different philosophical underpinnings.

Another context in which externalities apply is when globalization permits one player in a market who is unconcerned with biodiversity to undercut prices of another who is - creating a race to the bottom in regulations and conservation. This, in turn, may cause loss of natural capital with consequent erosion, water purity problems, diseases, desertification, and other outcomes that are not efficient in an economic sense. This concern is related to the subfield of sustainable development and its political relation, the anti-globalization movement.

Environmental economics was once distinct from resource economics. Natural resource economics as a subfield began when the main concern of researchers was the optimal commercial exploitation of natural resource stocks. But resource managers and policy-makers eventually began to pay attention to the broader importance of natural resources (e.g. values of fish and trees beyond just their commercial exploitation). It is now difficult to distinguish "environmental" and "natural resource" economics as separate fields as the two became associated with sustainability. Many of the more radical green economists split off to work on an alternate political economy.

Environmental economics was a major influence on the theories of natural capitalism and environmental finance, which could be said to be two sub-branches of environmental economics concerned with resource conservation in production, and the value of biodiversity to humans, respectively. The theory of natural capitalism (Hawken, Lovins, Lovins) goes further than traditional environmental economics by envisioning a world where natural services are considered on par with physical capital.

The more radical green economists reject neoclassical economics in favour of a new political economy beyond capitalism or communism that gives a greater emphasis to the interaction of the human economy and the natural environment, acknowledging that "economy is three-fifths of ecology" - Mike Nickerson. This political group is a proponent of a transition to renewable energy.

These more radical approaches would imply changes to money supply and likely also a bioregional democracy so that political, economic, and ecological "environmental limits" were all aligned, and not subject to the arbitrage normally possible under capitalism.

An emerging sub-field of environmental economics studies its intersection with development economics. Dubbed "envirodevonomics" by Michael Greenstone and B. Kelsey Jack in their paper "Envirodevonomics: A Research Agenda for a Young Field", the sub-field is primarily interested in studying "why environmental quality [is] so poor in developing countries." A strategy for better understanding this correlation between a country's GDP and its environmental quality involves analyzing how many of the central concepts of environmental economics, including market failures, externalities, and willingness to pay, may be complicated by the particular problems facing developing countries, such as political issues, lack of infrastructure, or inadequate financing tools, among many others.

In the field of law and economics, environmental law is studied from an economic perspective. The economic analysis of environmental law studies instruments such as zoning, expropriation, licensing, third party liability, safety regulation, mandatory insurance, and criminal sanctions. A book by Michael Faure (2003) surveys this literature.

Professional bodies
The main academic and professional organizations for the discipline of Environmental Economics are the Association of Environmental and Resource Economists (AERE) and the European Association for Environmental and Resource Economics (EAERE). The main academic and professional organization for the discipline of Ecological Economics is the International Society for Ecological Economics (ISEE). The main organization for Green Economics is the Green Economics Institute.

Hypotheses and theorems

 * Coase theorem
 * Porter hypothesis

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

title: Environmental economics


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CDR coding

In computer science CDR coding is a compressed data representation for Lisp linked lists. It was developed and patented by the MIT Artificial Intelligence Laboratory, and implemented in computer hardware in a number of Lisp machines derived from the MIT CADR.

CDR coding is in fact a fairly general idea; whenever a data object A ends in a reference to another data structure B, we can instead place the structure B itself there, overlapping and running off the end of A. By doing this we free the space required by the reference, which can add up if done many times, and also improve locality of reference, enhancing performance on modern machines. The transformation is especially effective for the cons-based lists it was created for; we free about half of the space for each node we perform this transformation on.

It is not always possible to perform this substitution, because there might not be a large enough chunk of free space beyond the end of A. Thus, some objects will end in a real reference, and some with the referenced object, and the machine must be able to tell by reading the final cell which one it is. This can be accomplished with some inefficiency in software by the use of tagged pointers, which allow a pointer in a final position to be specifically tagged as such, but is best done in hardware.

In the presence of mutable objects, CDR coding becomes more complex. If a reference is updated to point to another object, but currently has an object stored in that field, the object must be relocated, along with any other pointers to it. Not only are such moves typically expensive or impossible, but over time they cause fragmentation of the store. This problem is typically avoided by using CDR coding only on immutable data structures.

title: CDR coding


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Threaded code

In computer science, threaded code is a programming technique where the code has a form that essentially consists entirely of calls to subroutines. It is often used in compilers, which may generate code in that form or be implemented in that form themselves. The code may be processed by an interpreter or it may simply be a sequence of machine code call instructions.

Threaded code has better density than code generated by alternative generation techniques and by alternative calling conventions. In cached architectures, it may execute slightly slower. However, a program that is small enough to fit in a computer processor's cache may run faster than a larger program that suffers many cache misses. Small programs may also be faster at thread switching, when other programs have filled the cache.

Threaded code is best known for its use in many compilers of programming languages, such as Forth, many implementations of BASIC, some implementations of COBOL, early versions of B, and other languages for small minicomputers and for amateur radio satellites.

History
The common way to make computer programs is to use a compiler to translate source code (written in some symbolic language) to machine code. The resulting executable is typically fast but, because it is specific to a hardware platform, it isn't portable. A different approach is to generate instructions for a virtual machine and to use an interpreter on each hardware platform. The interpreter instantiates the virtual machine environment and executes the instructions. Thus, only the interpreter must be compiled.

Early computers had relatively little memory. For example, most Data General Nova, IBM 1130, and many of the first microcomputers had only 4 kB of RAM installed. Consequently, a lot of time was spent trying to find ways to reduce a program's size, to fit in the available memory.

One solution is to use an interpreter which reads the symbolic language a bit at a time, and calls functions to perform the actions. As the source code is typically much denser than the resulting machine code, this can reduce overall memory use. This was the reason Microsoft BASIC is an interpreter: its own code had to share the 4 kB memory of machines like the Altair 8800 with the user's source code. A compiler translates from a source language to machine code, so the compiler, source, and output must all be in memory at the same time. In an interpreter, there is no output.

Threaded code is a formatting style for compiled code that minimizes memory use. Instead of writing out every step of an operation at its every occurrence in the program, as was common in macro assemblers for instance, the compiler writes each common bit of code into a subroutine. Thus, each bit exists in only one place in memory (see "Don't repeat yourself"). The top-level application in these programs may consist of nothing but subroutine calls. Many of these subroutines, in turn, also consist of nothing but lower-level subroutine calls.

Mainframes and some early microprocessors such as the RCA 1802 required several instructions to call a subroutine. In the top-level application and in many subroutines, that sequence is constantly repeated, with only the subroutine address changing from one call to the next. This means that a program consisting of many function calls may have considerable amounts of repeated code as well.

To address this, threaded code systems used pseudo-code to represent function calls in a single operator. At run time, a tiny "interpreter" would scan over the top-level code, extract the subroutine's address in memory, and call it. In other systems, this same basic concept is implemented as a branch table, dispatch table, or virtual method table, all of which consist of a table of subroutine addresses.

During the 1970s, hardware designers spent considerable effort to make subroutine calls faster and simpler. On the improved designs, only a single instruction is expended to call a subroutine, so the use of a pseudo-instruction saves no room. Additionally, the performance of these calls is almost free of additional overhead. Today, though almost all programming languages focus on isolating code into subroutines, they do so for code clarity and maintainability, not to save space.

Threaded code systems save room by replacing that list of function calls, where only the subroutine address changes from one call to the next, with a list of execution tokens, which are essentially function calls with the call opcode(s) stripped off, leaving behind only a list of addresses.

Over the years, programmers have created many variations on that "interpreter" or "small selector". The particular address in the list of addresses may be extracted using an index, general-purpose register or pointer. The addresses may be direct or indirect, contiguous or non-contiguous (linked by pointers), relative or absolute, resolved at compile time or dynamically built. No single variation is "best" for all situations.

Development
To save space, programmers squeezed the lists of subroutine calls into simple lists of subroutine addresses, and used a small loop to call each subroutine in turn. For example, the following pseudocode uses this technique to add two numbers A and B. In the example, the list is labeled thread and a variable ip (Instruction Pointer) tracks our place within the list. Another variable sp (Stack Pointer) contains an address elsewhere in memory that is available to hold a value temporarily.

The calling loop at  is so simple that it can be repeated inline at the end of each subroutine. Control now jumps once, from the end of a subroutine to the start of another, instead of jumping twice via. For example:

This is called direct threaded code (DTC). Although the technique is older, the first widely circulated use of the term "threaded code" is probably James R. Bell's 1973 article "Threaded Code".

In 1970, Charles H. Moore invented a more compact arrangement, indirect threaded code (ITC), for his Forth virtual machine. Moore arrived at this arrangement because Nova minicomputers had an indirection bit in every address, which made ITC easy and fast. Later, he said that he found it so convenient that he propagated it into all later Forth designs.

Today, some Forth compilers generate direct-threaded code while others generate indirect-threaded code. The executables act the same either way.

Threading models
Practically all executable threaded code uses one or another of these methods for invoking subroutines (each method is called a "threading model").

Direct threading
Addresses in the thread are the addresses of machine language. This form is simple, but may have overheads because the thread consists only of machine addresses, so all further parameters must be loaded indirectly from memory. Some Forth systems produce direct-threaded code. On many machines direct-threading is faster than subroutine threading (see reference below).

An example of a stack machine might execute the sequence "push A, push B, add". That might be translated to the following thread and routines, where  is initialized to the address labeled   (i.e., the address where   is stored).

Alternatively, operands may be included in the thread. This can remove some indirection needed above, but makes the thread larger:

Indirect threading
Indirect threading uses pointers to locations that in turn point to machine code. The indirect pointer may be followed by operands which are stored in the indirect "block" rather than storing them repeatedly in the thread. Thus, indirect code is often more compact than direct-threaded code. The indirection typically makes it slower, though usually still faster than bytecode interpreters. Where the handler operands include both values and types, the space savings over direct-threaded code may be significant. Older FORTH systems typically produce indirect-threaded code.

For example, if the goal is to execute "push A, push B, add", the following might be used. Here,  is initialized to address , each code fragment  is found by double-indirecting through   and an indirect block; and any operands to the fragment are found in the indirect block following the fragment's address. This requires keeping the current subroutine in, unlike all previous examples where it contained the next subroutine to be called.

Subroutine threading
So-called "subroutine-threaded code" (also "call-threaded code") consists of a series of machine-language "call" instructions (or addresses of functions to "call", as opposed to direct threading's use of "jump"). Early compilers for ALGOL, Fortran, Cobol and some Forth systems often produced subroutine-threaded code. The code in many of these systems operated on a last-in-first-out (LIFO) stack of operands, for which compiler theory was well-developed. Most modern processors have special hardware support for subroutine "call" and "return" instructions, so the overhead of one extra machine instruction per dispatch is somewhat diminished.

Anton Ertl, the Gforth compiler's co-creator, stated that "in contrast to popular myths, subroutine threading is usually slower than direct threading". However, Ertl's most recent tests show that subroutine threading is faster than direct threading in 15 out of 25 test cases. More specifically, he found that direct threading is the fastest threading model on Xeon, Opteron, and Athlon processors, indirect threading is fastest on Pentium M processors, and subroutine threading is fastest on Pentium 4, Pentium III, and PPC processors.

As an example of call threading for "push A, push B, add":

Token threading
Token-threaded code implements the thread as a list of indices into a table of operations; the index width is naturally chosen to be as small as possible for density and efficiency. 1 byte / 8-bits is the natural choice for ease of programming, but smaller sizes like 4-bits, or larger like 12 or 16 bits, can be used depending on the number of operations supported. As long as the index width is chosen to be narrower than a machine pointer, it will naturally be more compact than the other threading types without much special effort by the programmer. It is usually half to three-fourths the size of other threadings, which are themselves a quarter to an eighth the size of non-threaded code. The table's pointers can either be indirect or direct. Some Forth compilers produce token-threaded code. Some programmers consider the "p-code" generated by some Pascal compilers, as well as the bytecodes used by .NET, Java, BASIC and some C compilers, to be token-threading.

A common approach, historically, is bytecode, which typically uses 8-bit opcodes with a stack-based virtual machine. The archetypal bytecode interpreter is known as a "decode and dispatch interpreter" and follows the form:

If the virtual machine uses only byte-size instructions,  is simply a fetch from , but often there are commonly used 1-byte instructions plus some less-common multibyte instructions (see complex instruction set computer), in which case   is more complex. The decoding of single byte opcodes can be very simply and efficiently handled by a branch table using the opcode directly as an index.

For instructions where the individual operations are simple, such as "push" and "add", the overhead involved in deciding what to execute is larger than the cost of actually executing it, so such interpreters are often much slower than machine code. However, for more complex ("compound") instructions, the overhead percentage is proportionally less significant.

There are times when token-threaded code can sometimes run faster than the equivalent machine code when that machine code ends up being too large to fit in the physical CPU's L1 instruction cache. The higher code density of threaded code, especially token-threaded code, can allow it to fit entirely in the L1 cache when it otherwise would not have, thereby avoiding cache thrashing. However, threaded code consumes both instruction cache (for the implementation of each operation) as well as data cache (for the bytecode and tables) unlike machine code which only consumes instruction cache; this means threaded code will eat into the budget for the amount of data that can be held for processing by the CPU at any given time. In any case, if the problem being computed involves applying a large number of operations to a small amount of data then using threaded code may be an ideal optimization.

Huffman threading
Huffman threaded code consists of lists of tokens stored as Huffman codes. A Huffman code is a variable-length string of bits that identifies a unique token. A Huffman-threaded interpreter locates subroutines using an index table or a tree of pointers that can be navigated by the Huffman code. Huffman-threaded code is one of the most compact representations known for a computer program. The index and codes are chosen by measuring the frequency of calls to each subroutine in the code. Frequent calls are given the shortest codes. Operations with approximately equal frequencies are given codes with nearly equal bit-lengths. Most Huffman-threaded systems have been implemented as direct-threaded Forth systems, and used to pack large amounts of slow-running code into small, cheap microcontrollers. Most published uses have been in smart cards, toys, calculators, and watches. The bit-oriented tokenized code used in PBASIC can be seen as a kind of Huffman-threaded code.

Lesser-used threading
An example is string threading, in which operations are identified by strings, usually looked up by a hash table. This was used in Charles H. Moore's earliest Forth implementations and in the University of Illinois's experimental hardware-interpreted computer language. It is also used in Bashforth.

RPL
HP's RPL, first introduced in the HP-18C calculator in 1986, is a type of proprietary hybrid (direct-threaded and indirect-threaded) threaded interpretive language (TIL) that, unlike other TILs, allows embedding of RPL "objects" into the "runstream", i.e. the stream of addresses through which the interpreter pointer advances. An RPL "object" can be thought of as a special data type whose in-memory structure contains an address to an "object prolog" at the start of the object, and then data or executable code follows. The object prolog determines how the object's body should be executed or processed. Using the "RPL inner loop", which was invented and patented by William C. Wickes in 1986 and published in 1988, execution follows like so:

 * 1) Dereference the IP (instruction pointer) and store it into O (current object pointer)
 * 2) Increment the IP by the length of one address pointer
 * 3) Dereference O and store its address in O_1 (this is the second level of indirection)
 * 4) Transfer control to next pointer or embedded object by setting the PC (program counter) to O_1 plus one address pointer
 * 5) Go back to step 1

This can be represented more precisely by:

O = [I] I = I + Δ PC = [O] + Δ

Where above, O is the current object pointer, I is the interpreter pointer, Δ is the length of one address word and the "[]" operator stands for "dereference".

When control is transferred to an object pointer or an embedded object, execution continues as follows:

PROLOG -> PROLOG (The prolog address at the start of the prolog code points to itself) IF O + Δ =/= PC   THEN GOTO INDIRECT (Test for direct execution) O = I - Δ (Correct O to point to start of embedded object) I = I + α (Correct I to point after embedded object where α is the length of the object) INDIRECT (Rest of prolog)

On HP's Saturn microprocessors that use RPL, there is a third level of indirection made possible by an architectural / programming trick which allows faster execution.

Branches
In all interpreters, a branch simply changes the thread pointer to a different address in the thread. A conditional jump-if-zero branch that jumps only if the top-of-stack value is zero could be implemented as shown below. This example uses the embedded parameter version of direct threading so the  line is the destination of where to jump if the condition is true, so it must be skipped  over if the branch is not taken.

Common amenities
Separating the data and return stacks in a machine eliminates a great deal of stack management code, substantially reducing the size of the threaded code. The dual-stack principle originated three times independently: for Burroughs large systems, Forth, and PostScript. It is used in some Java virtual machines.

Three registers are often present in a threaded virtual machine. Another one exists for passing data between subroutines ('words'). These are:
 * ip or i (instruction pointer) of the virtual machine (not to be confused with the program counter of the underlying hardware implementing the VM)
 * w (work pointer)
 * rp or r (return stack pointer)
 * sp or s (parameter stack pointer for passing parameters between words)

Often, threaded virtual machines, such as implementations of Forth, have a simple virtual machine at heart, consisting of three primitives. Those are:
 * 1) nest, also called docol
 * 2) unnest, or semi_s (s)
 * 3) next

In an indirect-threaded virtual machine, the one given here, the operations are:

title: Threaded code


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Texas Instruments

Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartered in Dallas, Texas. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog chips and embedded processors, which account for more than 80% of its revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers, and multi-core processors.

Texas Instruments emerged in 1951 after a reorganization of Geophysical Service Incorporated, a company founded in 1930 that manufactured equipment for use in the seismic industry, as well as defense electronics. TI produced the world's first commercial silicon transistor in 1954, and the same year designed and manufactured the first transistor radio. Jack Kilby invented the integrated circuit in 1958 while working at TI's Central Research Labs. TI also invented the hand-held calculator in 1967, and introduced the first single-chip microcontroller in 1970, which combined all the elements of computing onto one piece of silicon.

In 1987, TI invented the digital light processing device (also known as the DLP chip), which serves as the foundation for the company's DLP technology and DLP Cinema. TI released the popular TI-81 calculator in 1990, which made it a leader in the graphing calculator industry. Its defense business was sold to Raytheon Company in 1997; this allowed TI to strengthen its focus on digital solutions. After the acquisition of National Semiconductor in 2011, the company had a combined portfolio of 45,000 analog products and customer design tools. In the stock market, Texas Instruments is often regarded as an indicator for the semiconductor and electronics industry as a whole, since the company sells to more than 100,000 customers.

History

Texas Instruments was founded by Cecil H. Green, J. Erik Jonsson, Eugene McDermott, and Patrick E. Haggerty in 1951. McDermott was one of the original founders of Geophysical Service Inc. (GSI) in 1930. McDermott, Green, and Jonsson were GSI employees who purchased the company in 1941. In November 1945, Patrick Haggerty was hired as general manager of the Laboratory and Manufacturing (L&M) division, which focused on electronic equipment. By 1951, the L&M division, with its defense contracts, was growing faster than GSI's geophysical division. The company was reorganized and initially renamed General Instruments Inc. Because a firm named General Instrument already existed, the company was renamed Texas Instruments that same year. From 1956 to 1961, Fred Agnich of Dallas, later a Republican member of the Texas House of Representatives, was the Texas Instruments president. Geophysical Service, Inc. became a subsidiary of Texas Instruments. Early in 1988, most of GSI was sold to the Halliburton Company.

"Texas Instruments exists to create, make, and market useful products and services to satisfy the needs of its customers throughout the world."

Geophysical Service Incorporated
In 1930, J. Clarence Karcher and Eugene McDermott founded Geophysical Service, an early provider of seismic exploration services to the petroleum industry. In 1939, the company reorganized as Coronado Corp, an oil company with Geophysical Service Inc (GSI), now as a subsidiary. On December 6, 1941, McDermott along with three other GSI employees, J. Erik Jonsson, Cecil H. Green, and H. B. Peacock purchased GSI. During World War II, GSI expanded its services to include electronics for the U.S. Army, Army Signal Corps, and U.S. Navy. In 1951, the company changed its name to Texas Instruments, spun off to build seismographs for oil explorations and with GSI becoming a wholly owned subsidiary of the new company.

An early success came for TI-GSI in 1965, when GSI was able (under a Top Secret government contract) to monitor the Soviet Union's underground nuclear weapons testing under the ocean in Vela Uniform, a subset of Project Vela, to verify compliance of the Partial Nuclear Test Ban Treaty.

Texas Instruments also continued to manufacture equipment for use in the seismic industry, and GSI continued to provide seismic services. After selling (and repurchasing) GSI, TI finally sold the company to Halliburton in 1988, after which sale GSI ceased to exist as a separate entity.

Semiconductors
In early 1952, Texas Instruments purchased a patent license to produce germanium transistors from Western Electric, the manufacturing arm of AT&T, for US$25,000, beginning production by the end of the year. Haggerty brought Gordon Teal to the company due to his expertise in growing semiconductor crystals while at Bell Telephone Laboratories. Teal's first assignment was to direct TI's research laboratory. At the end of 1952, Texas Instruments announced that it had expanded to 2,000 employees and $17 million in sales.

Among his new hires was Willis Adcock, who joined TI early in 1953. Adcock, who like Teal was a physical chemist, began leading a small research group focused on the task of fabricating grown-junction, silicon, single-crystal, small-signal transistors. Adcock later became the first TI Principal Fellow.

First silicon transistor and integrated circuits

In January 1954, Morris Tanenbaum at Bell Telephone Laboratories created the first workable silicon transistor. This work was reported in the spring of 1954, at the IRE off-the-record conference on solid-state devices, and was later published in the Journal of Applied Physics. Working independently in April 1954, Gordon Teal at TI created the first commercial silicon transistor and tested it on April 14, 1954. On May 10, 1954, at the Institute of Radio Engineers National Conference on Airborne Electronics in Dayton, Ohio, Teal presented a paper: "Some Recent Developments in Silicon and Germanium Materials and Devices".

In 1954, Texas Instruments designed and manufactured the first transistor radio. The Regency TR-1 used germanium transistors, as silicon transistors were much more expensive at the time. This was an effort by Haggerty to increase market demand for transistors.

Jack Kilby, an employee at TI, invented the integrated circuit in 1958. Kilby recorded his initial ideas concerning the integrated circuit in July 1958, and successfully demonstrated the world's first working integrated circuit on September 12, 1958. Six months later, Robert Noyce of Fairchild Semiconductor (who went on to co-found Intel) independently developed the integrated circuit with integrated interconnect, and is also considered an inventor of the integrated circuit. In 1969, Kilby was awarded the National Medal of Science, and in 1982 he was inducted into the National Inventor's Hall of Fame. Kilby also won the 2000 Nobel Prize in Physics for his part of the invention of the integrated circuit. Noyce's chip, made at Fairchild, was made of silicon, while Kilby's chip was made of germanium. In 2008, TI named its new development laboratory "Kilby Labs" after Jack Kilby.

In 2011, Intel, Samsung, LG, ST-Ericsson, Huawei's HiSilicon Technologies subsidiary, Via Telecom, and three other undisclosed chipmakers licensed the C2C link specification developed by Arteris Inc. and Texas Instruments.

Standard TTL

The 7400 series of transistor-transistor logic chips, developed by Texas Instruments in the 1960s, popularized the use of integrated circuits in computer logic. The military-grade version of this was the 5400 series.

Microprocessor
Texas Instruments invented the hand-held calculator (a prototype called "Cal Tech") in 1967 and the single-chip microcomputer in 1971, was assigned the first patent on a single-chip microprocessor (invented by Gary Boone) on September 4, 1973. This was disputed by Gilbert Hyatt, formerly of the Micro Computer Company, in August 1990, when he was awarded a patent superseding TI's. This was overturned on June 19, 1996, in favor of TI (note: Intel is usually given credit with Texas Instruments for the almost-simultaneous invention of the microprocessor).

First speech synthesis chip
In 1978, Texas Instruments introduced the first single-chip linear predictive coding speech synthesizer. In 1976, TI began a feasibility study of memory-intensive applications for bubble memory then being developed. They soon focused on speech applications. This resulted in the development the TMC0280 one-chip linear predictive coding speech synthesizer, which was the first time a single silicon chip had electronically replicated the human voice. This was used in several TI commercial products beginning with Speak & Spell, which was introduced at the Summer Consumer Electronics Show in June 1978. In 2001, TI left the speech synthesis business, selling it to Sensory Inc. of Santa Clara, California.

Consumer electronics and computers
In May 1954, Texas Instruments designed and built a prototype of the world's first transistor radio, and, through a partnership with Industrial Development Engineering Associates of Indianapolis, Indiana, the 100% solid-state radio was sold to the public beginning in October of that year.

In the 1960s, company president Pat Haggerty had a team that included Jack Kilby to work on a handheld calculator project. Kilby and two other colleagues created the Cal-Tech, a three-pound battery-powered calculator that could do basic math and fit six-digit numbers on its display. This 4.25 x 6.15 x 1.75 inch calculator's processor would originate the vast majority of Texas Instruments’ revenue.

In 1973, the handheld calculator SR-10 (named after slide rule) and in 1974, the handheld scientific calculator SR-50 were issued by TI. Both had red LED-segments numeric displays. The optical design of the SR-50 is somewhat similar to the HP-35 edited by Hewlett-Packard before in early 1972, but buttons for the operations "+", "–", ... are in the right of the number block and the decimal point lies between two neighboring digits.

TI continued to be active in the consumer electronics market through the 1970s and 1980s. Early on, this also included two digital clock models – one for desk and the other a bedside alarm. From this sprang what became the Time Products Division, which made LED watches. Though these LED watches enjoyed early commercial success due to excellent quality, it was short-lived due to poor battery life. LEDs were replaced with LCD watches for a short time, but these could not compete because of styling issues, excessive makes and models, and price points. The watches were manufactured in Dallas and then Lubbock, Texas. Several spin-offs of the Speak & Spell, such as the Speak & Read and Speak & Math, were introduced soon thereafter.

In 1979, TI entered the home computer market with the TI-99/4, a competitor to computers such as the Apple II, TRS-80, and the later Atari 400/800 and VIC-20. By late 1982, TI was dominating the U.S. home computer market, shipping 5,000 computers a day from their factory in Lubbock. It discontinued the TI-99/4A (1981), the sequel to the 99/4, in late 1983 amid an intense price war waged primarily against Commodore. At the 1983 Winter CES, TI showed models 99/2 and the Compact Computer 40, the latter aimed at professional users. The TI Professional (1983) ultimately joined the ranks of the many unsuccessful MS-DOS and x86-based—but non-compatible —competitors to the IBM PC (the founders of Compaq, an early leader in PC compatibles, all came from TI). The company for years successfully made and sold PC-compatible laptops before withdrawing from the market and selling its product line to Acer in 1998.

Defense electronics

TI entered the defense electronics market in 1942 with submarine detection equipment, based on the seismic exploration technology previously developed for the oil industry. The division responsible for these products was known at different times as the Laboratory & Manufacturing Division, the Apparatus Division, the Equipment Group, and the Defense Systems & Electronics Group (DSEG).

During the early 1980s, TI instituted a quality program which included Juran training, as well as promoting statistical process control, Taguchi methods, and Design for Six Sigma. In the late 1980s, the company, along with Eastman Kodak and Allied Signal, began involvement with Motorola, institutionalizing Motorola's Six Sigma methodology. Motorola, which originally developed the Six Sigma methodology, began this work in 1982. In 1992, the DSEG division of Texas Instruments' quality-improvement efforts were rewarded by winning the Malcolm Baldrige National Quality Award for manufacturing.

Infrared and radar systems
TI developed the AAA-4 infrared search and track device in the late 1950s and early 1960s for the F-4B Phantom for passive scanning of jet-engine emissions, but it possessed limited capabilities and was eliminated on F-4Ds and later models.

In 1956, TI began research on infrared technology that led to several line scanner contracts and with the addition of a second scan mirror the invention of the first forward looking infrared (FLIR) in 1963 with production beginning in 1966. In 1972, TI invented the common module FLIR concept, greatly reducing cost and allowing reuse of common components.

TI went on to produce side-looking radar systems, the first terrain-following radar and surveillance radar systems for both the military and FAA. TI demonstrated the first solid-state radar called Molecular Electronics for Radar Applications. In 1976, TI developed a microwave landing system prototype. In 1984, TI developed the first inverse synthetic aperture radar. The first single-chip gallium arsenide radar module was developed. In 1991, the military microwave integrated circuit program was initiated—a joint effort with Raytheon.

Missiles and laser-guided bombs
In 1961, TI won the guidance and control system contract for the defense suppression AGM-45 Shrike antiradiation missile. This led later to the prime on the high-speed antiradiation missile (AGM-88 HARM) development contract in 1974 and production in 1981.

In 1964, TI began development of the first laser guidance system for precision-guided munitions, leading to the Paveway series of laser-guided bombs (LGBs). The first LGB was the BOLT-117.

In 1969, TI won the Harpoon (missile) Seeker contract. In 1986, TI won the Army FGM-148 Javelin fire-and-forget man portable antitank guided missile in a joint venture with Martin Marietta. In 1991, TI was awarded the contract for the AGM-154 Joint Standoff Weapon.

In 1988, TI paid the U.S. government $5.2 million "to settle allegations one of its divisions overcharged the government on contracts for guided missiles sold to the Navy".

Military computers
Because of TI's research and development of military temperature-range silicon transistors and integrated circuits (ICs), TI won contracts for the first IC-based computer for the U.S. Air Force in 1961 (molecular electronic computer) and for ICs for the Minuteman Missile the following year. In 1968, TI developed the data systems for Mariner Program. In 1991 TI won the F-22 Radar and Computer development contract.

Divestiture to Raytheon
As the defense industry consolidated, TI sold its defense business to the Raytheon Company in 1997 for $2.95 billion. The Department of Justice required that Raytheon divest the TI Monolithic Microwave Integrated Circuit (MMIC) operations after closing the transaction. The TI MMIC business accounted for less than $40 million in 1996 revenues, or roughly 2% of the $1.8 billion in total TI defense revenues, and was sold to TriQuint Semiconductor, Inc. Raytheon retained its own existing MMIC capabilities and has the right to license TI's MMIC technology for use in future product applications from TriQuint.

Shortly after Raytheon acquired TI DSEG, Raytheon then acquired Hughes Aircraft from General Motors. Raytheon then owned TI's mercury cadmium telluride detector business and infrared (IR) systems group. In California, it also had Hughes infrared detector and an IR systems business. When again the US government forced Raytheon to divest itself of a duplicate capability, the company kept the TI IR systems business and the Hughes detector business. As a result of these acquisitions, these former arch rivals of TI systems and Hughes detectors work together.

Immediately after acquisition, DSEG was known as Raytheon TI Systems (RTIS). It is now fully integrated into Raytheon and this designation no longer exists.

Artificial intelligence
TI was active in the area of artificial intelligence in the 1980s. In addition to ongoing developments in speech and signal processing and recognition, it developed and sold the Explorer computer family of Lisp machines. For the Explorer, a special 32-bit Lisp microprocessor was developed, which was used in the Explorer II and the TI MicroExplorer (a Lisp Machine on a NuBus board for the Apple Macintosh). AI application software developed by TI for the Explorer included the gate assignment system for United Airlines, described as "an artificial intelligence program that captures the combined experience and knowledge of a half-dozen United operations experts." In software for the PC, they introduced "Personal Consultant", a rule-based expert system development tool and runtime engine, followed by "Personal Consultant Plus" written in the Lisp-like language from MIT known as Scheme, and the natural language menu system NLMenu.

Sensors and controls
TI was a major original-equipment manufacturer of sensor, control, protection, and RFID products for the automotive, appliance, aircraft, and other industries. The Sensors & Controls division was headquartered in Attleboro, Massachusetts.

By the mid-1980s, industrial computers known as PLC's (programmable logic controllers) were separated from Sensors & Controls as the Industrial Systems Division, which was sold in the early 1990s to Siemens.

In 2006, Bain Capital LLC, a private equity firm, purchased the Sensors & Controls division for $3.0 billion in cash. The RFID portion of the division remained part of TI, transferring to the Application Specific Products business unit of the Semiconductor division, with the newly formed independent company based in Attleboro taking the name Sensata Technologies.

Software
In 1997, TI sold its software division, along with its main products such as the CA Gen, to Sterling Software, which is now part of Computer Associates. However, TI still owns small pieces of software, such as the software for calculators such as the TI Interactive!. TI also creates a significant amount of target software for its digital signal processors, along with host-based tools for creating DSP applications.

TI.com
In 2000, Texas Instruments first implemented an e-commerce platform on TI.com as a way to sell its Code Composer Studio software tool directly to customers. With TI.com, purchase managers and design engineers have access to TI products that are immediately available for shipping. The platform has grown to include tens of thousands of TI analog and embedded processing products. In 2020, TI added several features, including full and custom quantity reels, multiple payment options, lines of credit, and flat-rate shipping.

Restatement
On August 6, 1999, TI announced the restatement of its results for parts of 1998 and the first quarter of 1999 after a review by the Securities and Exchange Commission over the timing of charges for a plant closing and writedown.

Finances
For the fiscal year 2017, Texas Instruments reported earnings of $3.682 billion, with an annual revenue of $14.961 billion, an increase of 11.9% over the previous fiscal cycle. TI shares traded at over $82 per share, and its market capitalization was valued at over $88.0 billion in October 2018. As of 2018, TI ranked 192nd on the Fortune 500 list of the largest United States corporations by revenue.

Divisions
As of 2016, TI is made up of four divisions: analog products, embedded processors, digital light processing, and educational technology.

As of January 2021, the industrial market accounts for 41 percent of TI's annual revenue, and the automotive market accounts for 21 percent.

Other businesses
TI's remaining businesses consisting of DLP products (primarily used in projectors to create high-definition images), calculators and certain custom semiconductors known as application-specific integrated circuits.

DLP Products
DLP is a trademark under which Texas Instruments sells technology regarding TVs, video projectors, and digital cinema. On February 2, 2000, Philippe Binant, technical manager of Digital Cinema Project at Gaumont in France, realized the first digital cinema projection in Europe with the DLP CINEMA technology developed by TI DLP technology enables a diverse range of display and advanced light control applications spanning industrial, enterprise, automotive, and consumer market segments.

 * Custom application-specific integrated circuits (ASICs)

The ASICs business develops more complex integrated-circuit solutions for clients on a custom basis.

Educational technology
TI has produced educational toys for children, including the Little Professor in 1976 and Dataman in 1977.

TI produces a range of calculators, with the TI-30 being one of the most popular early calculators. TI has also developed a line of graphing calculators, the first being the TI-81, and most popular being the TI-83 Plus (with the TI-84 Plus being an updated equivalent).

Many TI calculators are still sold without graphing capabilities. The TI-30 has been replaced by the TI-30X IIS. Also, some financial calculators are for sale on the TI website.

In 2007, TI released the TI-Nspire family of calculators and computer software that has similar capabilities to the calculators.

Less than 3% of Texas Instruments’ overall revenue comes from calculators, part of the $1.43 billion revenue in the "Other" section in the company's 2018 annual report. Nevertheless, the calculators are a lucrative product. For example, estimates have a $15 to $20 cost to produce TI-84 Plus which likely has a profit margin of at least 50%.

Throughout the 1980s, Texas Instruments worked closely with National Council of Teachers of Mathematics (NCTM) to develop a calculator to become the educational standard. In 1986, Connecticut School Board became the first to require a graphing calculator on state-mandated exams. Chicago Public Schools gave a free calculator to every student, beginning in the fourth grade, in 1988. New York required the calculator in 1992 for its Regents exams after first allowing it the previous year. The College Board required calculators on the Advanced Placement tests in 1993 and allowed calculators on the SAT a year later. Texas Instruments provides free services to the College Board, which administers AP tests and the SAT, and also has a group called Teachers Teaching for Technology (T3), which educates teachers on how to use its calculators.

TI calculator community
In the 1990s, with the advent of TI's graphing calculator series, programming became popular among some students. The TI-8x series of calculators (beginning with the TI-81) came with a built-in BASIC interpreter, through which simple programs could be created. The TI-83 was the first in the series to receive native assembly. Around the same time that these programs were first being written, programmers began creating websites to host their work, along with tutorials and other calculator-relevant information. This led to the formation of TI calculator webrings and eventually a few large communities, including ticalc.org.

The TI community reached the height of its popularity in the early 2000s, with many new websites and programming groups being started. In fact, the aforementioned community sites were exploding with activity, with close to 100 programs being uploaded daily by users of the sites. Also, a competition existed between both sites to be the top site in the community, which helped increase interest and activity in the community.

One of the common unifying forces that has united the community over the years has been the rather contentious relationship with TI regarding control over its graphing calculators. TI graphing calculators generally fall into two distinct groups—the older ones powered by the Zilog Z80 and the newer ones running on the Motorola 68000 series. Both lines of calculators are locked by TI with checks in the hardware and through the signing of software to disable use of custom operating systems. However, users discovered the keys and published them in 2009. TI responded by sending invalid DMCA takedown notices, causing the Texas Instruments signing key controversy.

Competitors
TI has the largest market share in the analog semiconductor industry, accounting for over $10 billion of the total $57 billion market in 2020.

Acquisitions

 * In 1996, TI acquired Tartan, Inc.
 * In 1997, TI acquired Amati Communications for $395 million.
 * In 1998, TI acquired GO DSP.
 * In 1998, TI acquired the standard logic (semiconductor) product lines from Harris Semiconductor, which included the CD4000, HC4xxx, HCT, FCT, and ACT product families.
 * In 1999, TI acquired Libit Signal Processing Ltd. of Herzlia, Israel for approximately $365 million in cash.
 * In 1999, TI acquired Butterfly VLSI, Ltd. for approximately $50 million.
 * In 1999, TI acquired Telogy Networks for $457 million.
 * In 1999, TI acquired Unitrode Corporation (NYSE:UTR).
 * In 2000, TI acquired Burr-Brown Corporation for $7.6 billion.
 * In 2001, TI squired Graychip.
 * In 2003, TI acquired Radia Inc, a San-Jose based companied who had developed a developed a ASIC WiFi front end prototype without the base band processor, for about $320 million. The company has an Israeli home office.
 * In 2006, TI acquired Chipcon for about $200 million.
 * In 2009, TI acquired CICLON and Luminary Micro.
 * In 2011, TI acquired National Semiconductor for $6.5 billion.
 * In 2021, TI acquired an operational 300mm fabrication plant located in Lehi, Utah from Micron for $900 million.
 * In 2022, TI acquired icDirectory France

National Semiconductor acquisition
On April 4, 2011, Texas Instruments announced that it had agreed to buy National Semiconductor for $6.5 billion in cash. TI paid $25 per share of National Semiconductor stock, which was an 80% premium over the share price of $14.07 as of April 4, 2011, close. The deal made TI the world's largest maker of analog technology components. The companies formally merged on September 23, 2011.

title: Texas Instruments