text:
1639

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January–March

 * January 19 – Hämeenlinna (Tavastehus) is granted privileges, after it separates from the Vanaja parish, as its own city in Tavastia.
 * c. January – The first printing press in British North America is started in Cambridge, Massachusetts, by Stephen Daye.
 * February 18 – In the course of the Eighty Years' War, a sea battle is fought in the English Channel off of the coast of Dunkirk between the navies of the United Provinces of the Netherlands, with 12 warships, and Spain, with 12 galleons and eight other ships. The Spanish are forced to flee after three of their ships are lost and 1,600 Spaniards killed or injured, while the Dutch sustain 1,700 casualties without the loss of a ship.

 * March 3 – The early settlement of Taunton, Massachusetts, is incorporated as a town.
 * March 13 – Harvard University is named for clergyman John Harvard.

April–June

 * April 14 – In the Battle of Chemnitz, Swedish forces under Johan Banér inflict a crushing defeat on the army of the Holy Roman Empire, prolonging the Thirty Years' War and allowing the Swedes to occupy Pirna and advance into Bohemia.
 * April 22 – Pope Urban VIII issues a papal bull prohibiting slavery in the New World colonies of Spain and Portugal, encompassing most of Latin America.
 * April – Italian-born Cardinal Mazarin, apostolic nuncio to Paris and adviser to Cardinal Richelieu, is naturalized French by letters patent; in December, he leaves the service of Rome to enter that of King Louis XIII of France.
 * May 2 – After a 40-day siege, the Dutch East India Company Army captures the Trincomalee Fort on the island of Ceylon (now Sri Lanka) from the Portuguese Empire.
 * May 28 – King Charles I of England arrives with his army at Berwick-upon-Tweed as the first of the Bishops' Wars breaks out between the English Army and the Scottish Covenanters.
 * June 18
 * The Treaty of Berwick is signed between Charles I and the Scots.
 * On the same day, the first battle of the Bishops' Wars is fought by Earl Marischal and the Marquess of Montrose when they lead a Covenanter army of 9,000 men past Muchalls Castle over the Causey Mounth to fight at the Bridge of Dee in Scotland.

July–September

 * July 1 – Parthenius I becomes the new leader of the Eastern Orthodox Christian church as he is selected as Patriarch of Constantinople, succeeding Cyril II.
 * July 16 – A revolt in France begins in Normandy with the assassination of tax collector Charles Le Poupinel while he is working in the town of Avranches. The rebellion is brutally crushed on November 30.
 * August 22 – The British East India Company buys a strip of land from King Peda Venkata Raya of the Vijayanagara Empire for the construction of Fort St. George, the first settlement of British India, so founding modern-day Chennai, capital city of the Indian state of Tamil Nadu (celebrated as Madras Day).
 * September 3 – The alliance of cantons in Switzerland known as the Three Leagues or Raetia agrees with Spain to bring Italy's Valtellina area back into the alliance, on the condition that the Catholic faith of the natives be respected.
 * September 18 – Dutch Navy Admiral Maarten Tromp introduces the line of battle tactic in a battle in the English Channel against a much larger force of Spanish Navy ships, driving off 67 ships with his fleet of 29.

October–December

 * October 31 – Naval Battle of the Downs: A Republic of the United Provinces fleet decisively defeats a Spanish fleet in English waters.
 * November 30 – In Normandy, the revolt of the va-nu-pieds is crushed by the troops of French Army Colonel Jean de Gassion under orders of Armand Jean du Plessis, Cardinal Richelieu, with 300 of the rebels killed.
 * December 4 – English astronomer Jeremiah Horrocks makes the first successful prediction and observation of a transit of Venus.

Date unknown

 * The Casiquiare canal, a river forming a natural channel between the Amazon River and Orinoco River basins, is first encountered by Europeans, an expedition led by Pedro Teixeira and Cristóbal Diatristán de Acuña.
 * French nobleman Jérôme le Royer de la Dauversière obtains the seigneurial title to the island of Montreal in New France (modern-day Quebec) in the name of the Société Notre-Dame de Montréal to establish a Roman Catholic mission to evangelize indigenous peoples.
 * Russian Cossacks advance over the Urals to the Pacific, to Okhotsk.
 * Sakoku, the isolationist foreign policy of Japan, comes fully into effect.
 * Dejima, an island trading post off Nagasaki, becomes the only official port of trade allowed for Europeans, with the multi-national United East Indies Company (Vereenigde Oostindische Compagnie) as the only European party officially allowed. Trading parties from China, India and other places are still officially allowed, though the VOC will become the usual broker for them.
 * Japanese wives and children of Dutch and British people from Hirado are sent to Batavia (Asian headquarters of the VOC, renamed Jakarta by the Japanese around three centuries later) on Dutch ships.
 * The Treaty of Zuhab is signed between the Ottoman (Turkish) Empire and Safavid Persia, delineating the modern Turkey-Iran and Iraq-Iran border lines.

January–March

 * January 1
 * Jacob Knijff, Dutch painter (d. 1681)
 * Sir Thomas Spencer, 3rd Baronet, English Member of Parliament (d. 1685)
 * January 3 – Éléonore Desmier d'Olbreuse, French Huguenot noblewoman, grandmother of George II of Great Britain, great-grandmother of Frederick the Great (d. 1722)
 * January 5 – Otto Wilhelm Königsmarck, Swedish military officer (d. 1688)
 * January 16 – John Proby, English politician (d. 1710)
 * January 17 – Sir Francis Lee, 4th Baronet, English Member of Parliament (d. 1667)
 * January 19 – Noël Alexandre, French theologian and ecclesiastical historian (d. 1724)
 * January 20 – Hungerford Dunch, English politician (d. 1680)
 * January 29 – Gover Le Buen, Dutch revolutionary fighter (d. 1712)
 * January 31 – Duke Bernhard of Schleswig-Holstein-Sonderburg-Plön, German-Danish general (d. 1676)
 * February 4 – Alessandro Melani, Italian composer (d. 1703)
 * February 6 – Daniel Georg Morhof, German writer and scholar (d. 1691)
 * February 12 – Juan García de Salazar, Spanish Baroque composer (d. 1710)
 * February 17 – Claude Estiennot de la Serre, French historian (d. 1699)
 * February 27 – Adriaen van Bloemen, Flemish painter, printmaker, draughtsman and engraver (d. 1697)
 * March 7 – Charles Stewart, 3rd Duke of Richmond, English nobleman (d. 1672)
 * March 20 – Ivan Mazepa, Hetman of Ukraine (d. 1709)
 * March 30 – Elanor Allerton, English-born American colonist (d. 1674)

April–June

 * April 3 – Alessandro Stradella, Italian composer (k. 1682)
 * April 12 – Martin Lister, English naturalist and physician (d. 1712)
 * April 13 – Joan Leonardsz Blasius, Dutch writer (d. 1672)
 * April 16 – Alessandro Baratta, Italian painter, engraver (d. 1714)
 * April 24 – Johann Benedict Carpzov II, German theologian (d. 1699)
 * April 29 – François Nepveu, French Jesuit writer on ascetical subjects (d. 1708)
 * May 8 – Giovanni Battista Gaulli, Italian artist working in the High Baroque and early Rococo periods (d. 1709)
 * May 10 – Peleg Sanford, Rhode Island colonial governor (d. 1701)
 * May 19 – Charles Weston, 3rd Earl of Portland, English nobleman (d. 1665)
 * May 27 – Laura Martinozzi, Duchess consort of Modena (d. 1687)
 * June 21 – Increase Mather, American minister (d. 1723)

July–September

 * July 8 – John Vaughan, 3rd Earl of Carbery, English politician and Irish nobleman (d. 1713)
 * July 15 – Richard Butler, 1st Earl of Arran, Irish soldier (d. 1686)
 * August 18 – William Lowther, English landowner and politician (d. 1705)
 * August 28 – Marie Mancini, Italian courtier, third of the five Mancini sisters (d. 1715)
 * August 30 – Cornelia van der Veer, Dutch poet (d. 1704)
 * September 7 – David Martin, French theologian (d. 1721)
 * September 8 – William Trumbull, English diplomat and politician (d. 1716)
 * September 17 – Hans Herr, Swiss-born Mennonite bishop (d. 1725)
 * September 21 – Robbert Duval, painter from the Northern Netherlands (d. 1732)
 * September 29
 * William Russell, Lord Russell, English politician (d. 1683)
 * Sir John Seton, 1st Baronet of Nova Scotia (d. 1686)

October–December

 * October 14 – Simon van der Stel, last Commander and first Governor of the Cape Colony (d. 1712)
 * October 17 – Charles-Claude Genest, French dramatist and playwright (d. 1719)
 * November 17 – Eleazer Kimberly, Secretary of the State of Connecticut (d. 1709)
 * November 21 – Fortunatus Hueber, German Franciscan historian and theologian (d. 1706)
 * December 3 – Isidoro de Atondo y Antillon, Spanish admiral (d. 1689)
 * December 18 – Gottfried Kirch, German astronomer, first 'Astronomer Royal' in Berlin (d. 1710)
 * December 22 – Jean Racine, French dramatist (d. 1699)
 * December 28 – Dirk van Bleiswijk, Dutch politician, writer (d. 1681)
 * December 29 – Muhammad Sultan, Mughal Empire emperor (d. 1676)

Date unknown

 * Yair Bacharach, German rabbi (d. 1702)
 * Consort Donggo, concubine of the Shunzhi Emperor of the Qing Dynasty (d. 1660)
 * Dirck Ferreris, Dutch painter (d. 1693)
 * Caspar Netscher, Dutch painter (d. 1684)
 * Samuel Peterson, early Swedish settler of New Sweden, founder of modern-day Wilmington (d. 1689)

Deaths

 * January – Shackerley Marmion, English dramatist (b. 1603)
 * January 14 – Sophie of Brunswick-Lüneburg, Margrave of Brandenburg-Ansbach and Brandenburg-Kulmbach, Duchess of Hunters Village (b. 1563)
 * January 20 – Mustafa I, Ottoman Sultan (b. 1592)
 * January 23 – Francisco Maldonado da Silva, Peruvian Jewish poet (b. 1592)
 * January 24 – Georg Jenatsch, Swiss politician (b. 1596)
 * February 5 – Augusta of Denmark, Duchess Consort of Holstein-Gottorp (b. 1580)
 * March 16 – Pieter de Neyn, Dutch painter (b. 1597)
 * April 1 – Johann Philipp, Duke of Saxe-Altenburg, German Duke (b. 1597)
 * April 2 – Nicolaes Olycan, Dutch businessman (b. 1599)
 * April 6
 * Berlinghiero Gessi, Italian Catholic cardinal (b. 1563)
 * John Matthew Rispoli, major Maltese philosopher of great erudition (b. 1582)
 * April 9 – Albret Skeel, State Admiral of Denmark (b. 1572)
 * May 13 – Peter Lauremberg, German writer and professor (b. 1585)
 * May 21 – Tommaso Campanella, Italian theologian and poet (b. 1568)
 * June 1 – Melchior Franck, German composer (b. c. 1579)
 * June 6 – Peter Crüger, German astronomer and mathematician (b. 1580)
 * July 18 – Bernard of Saxe-Weimar, German general (b. 1604)
 * August 4 – Juan Ruiz de Alarcón, Mexican dramatist (b. c. 1571)
 * August 6 – Hans van Steenwinckel the Younger, Danish architect (b. 1587)
 * August 20 – Martin Opitz von Boberfeld, German poet (b. 1597)
 * August 21 – Henry Wenceslaus, Duke of Oels-Bernstadt, Duke of Bernstadt (1617–1639) (b. 1592)
 * September 20 – Johannes Meursius, Dutch classical scholar (b. 1579)
 * September 28 – Louis de Nogaret de La Valette, French Catholic Cardinal (b. 1593)
 * October 8 – Frances Howard, Duchess of Richmond, British duchess (b. 1578)
 * October 28 – Stefano Landi, Italian composer (b. 1587)
 * November 3 – Martin de Porres, Peruvian monk, Roman Catholic saint (b. 1579)
 * November 4 – Thomas Finch, 2nd Earl of Winchilsea, Member of Parliament (b. 1578)
 * November 7 – Thomas Arundell, 1st Baron Arundell of Wardour, English politician (b. c. 1560)
 * November 8 – Richard Knightley, English politician (b. 1593)
 * November 26 – John Spottiswoode, Scottish archbishop and historian (b. 1565)
 * December 15 – Muzio Oddi, Italian mathematician (b. 1569)
 * December 17 – Nils Turesson Bielke, Swedish politician (b. 1569)
 * December 25 – John Christian of Brieg, Duke of Brzeg (b. 1591)
 * Date unknown – Madeleine du Fargis, French courtier
 * Approximate date – John Ford, English dramatist (b. 1586)

title: 1639


text:
100BaseVG

100BaseVG is a 100 Mbit/s Ethernet standard specified to run over four pairs of Category 3 cable (cable also known as voice grade, hence the "VG"). It is also called 100VG-AnyLAN because it was defined to carry both Ethernet and Token Ring frame types.

100BaseVG was originally proposed by Hewlett-Packard, ratified by the IEEE in 1995 and was practically extinct by 1998. In 2001 IEEE recorded the status of its 100BaseVG standard as being a "Withdrawn Standard" (defined as "A standard which is no longer maintained and which may contain significant obsolete or erroneous information.")

Standardization
100BaseVG started in the IEEE 802.3 committee as Fast Ethernet. One faction wanted to keep carrier-sense multiple access with collision detection (CSMA/CD) in order to keep it pure Ethernet, even though the collision domain problem limited the distances to one tenth that of 10BASE-T. Another faction wanted to change to a polling architecture from the hub (they called it "Demand Priority Protocol") in order to maintain the 10BASE-T distances, and also to make it a deterministic protocol. The first faction argued that, since IEEE 802.3 was the Ethernet committee, it was not the place to develop a different protocol. Thus, the IEEE 802.12 committee was formed and standardized 100BaseVG.

Physical layer
The physical layer requires four twisted pairs of "voice-grade" cabling for a link, so Category 3 cables or better can be used. While control signaling uses two pairs for each direction simultaneously, all four pairs are switched to a single direction during data transmission, as required and defined during control signaling. This makes 100BaseVG an inherently half-duplex medium like e.g. 10BASE5 (yet faster) but without the CSMA/CD drawbacks.

100BaseVG also supports full-duplex operation over optical fiber or over two pairs of shielded twisted pair.

Multiplexing
Instead of following the Fast Ethernet standard for twisted pair cabling by using only 2 pairs of wires, 100VG-AnyLAN used all four pairs in either Category 3 or Category 5 twisted pair cable. The design goals were to avoid the radio frequency radiation emitted at the higher frequencies required by Fast Ethernet and to leverage existing wiring installations of Category 3 cabling that most organizations had recently installed to support 10 megabit twisted-pair Ethernet. This had the additional advantage of being less susceptible to external sources of RF interference such as other network cables, fluorescent lights, and high power lines. They multiplexed the signal across all 8 wires thereby lowering the frequency and making it more robust. This presented a problem with early installations that borrowed one unused twisted pair for telephone traffic but those installations were uncommon.

Deterministic
When Ethernet became Fast Ethernet, it continued to use the CSMA/CD mechanism to manage traffic on the network cable. 100VG took advantage of the token passing concept that made ARCNET and Token Ring popular in order to provide consistent performance no matter how large the network became. It removed the token passing responsibility from the wiring and network nodes and placed it internal to the 100VG-AnyLAN hubs. These hubs contained the rotating token that never left the hub itself. When a node wanted to transmit data, it would raise a bit on its hub port connection that indicated to the hub that it was ready. As the token passed by a ready hub port, it would then open up traffic to that node. Because the token stayed within the hub, it did not have to traverse long cables going to every node as in ARCNET and Token Ring, thereby becoming faster than those other deterministic networking standards and being less susceptible to cabling problems, network card failures, and line interference. Real-life load testing showed 100VG-AnyLAN reaching 95% of its theoretical network speed instead of about 45% as in Fast Ethernet when using hubs. Fast Ethernet switches were not commonplace at first because of high cost and limited availability so, initially, 100VG had a significant performance advantage.

Demand Priority
Certain workloads demand their data be delivered at particular times - video and audio are good examples. On lightly used networks this traffic can be sent as normal data, but on busy networks, retransmission delays can push delivery outside the jitter limits of the data.

VG introduced the concept of Demand Priority to address this problem. When a node requests the ability to send data, it indicates this has high or normal priority. High-priority data is given transmission permission as soon as possible, typically as soon as any current data packet is completed. By letting the hub manage access, the architecture can guarantee required bandwidth and requested service priority to particular applications or nodes. It also can guarantee that the network can be scaled up (enlarged) without loss of bandwidth.

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

title: 100BaseVG


text:
10BASE2

10BASE2 (also known as cheapernet, thin Ethernet, thinnet, and thinwire) is a variant of Ethernet that uses thin coaxial cable terminated with BNC connectors to build a local area network.

During the mid to late 1980s, this was the dominant 10 Mbit/s Ethernet standard.

The use of twisted pair networks competed with 10BASE2's use of a single coaxial cable. In 1988, Ethernet over twisted pair was introduced, running at the same speed of 10 Mbit/s. In 1995, the Fast Ethernet standard upgraded the speed to 100 Mbit/s, and no such speed improvement was ever made for thinnet. By 2001, prices for Fast Ethernet cards had fallen to under $50. By 2003, Wi-Fi networking equipment was widely available and affordable.

Due to the immense demand for high-speed networking, the low cost of Category 5 cable, and the popularity of 802.11 wireless networks, both 10BASE2 and 10BASE5 have become increasingly obsolete, though devices still exist in some locations. As of 2011, IEEE 802.3 has deprecated this standard for new installations.

Name origination
The name 10BASE2 is derived from several characteristics of the physical medium. The 10 comes from the transmission speed of 10 Mbit/s. The BASE stands for baseband signaling, and the 2 for a maximum segment length approaching 200 m (the actual maximum length is 185 m).

Signal encoding
10 Mbit/s Ethernet uses Manchester coding. A binary zero is indicated by a low-to-high transition in the middle of the bit period and a binary one is indicated by a high-to-low transition in the middle of the bit period. Manchester coding allows the clock to be recovered from the signal. However, the additional transitions associated with it double the signal bandwidth.

Network design
10BASE2 coax cables have a maximum length of 185 m. The maximum practical number of nodes that can be connected to a 10BASE2 segment is limited to 30 with a minimum distance of 0.5 m between devices. In a 10BASE2 network, each stretch of cable is connected to the transceiver (which is usually built into the network adaptor) using a BNC T-connector, with one stretch connected to each female connector of the T. The T-connector must be plugged directly into the network adaptor with no cable in between.

As is the case with most other high-speed buses, Ethernet segments have to be terminated with a resistor at each end. Each end of the cable has a 50 ohm (Ω) resistor attached. Typically this resistor is built into a male BNC and attached to the last device on the bus. This is most commonly connected directly to the T-connector on a workstation. If termination is missing, or if there is a break in the cable, the AC signal on the bus is reflected, rather than dissipated, when it reaches the end. This reflected signal is indistinguishable from a collision, so no communication can take place.

Some terminators have a metallic chain attached to them for grounding purposes. The cable should be grounded only at one end. Grounding the terminators at both may produce a ground loop and can cause network outages or data corruption when swells of electricity traverse the coaxial cabling's outer shield.

When wiring a 10BASE2 network, special care has to be taken to ensure that cables are properly connected to all T-connectors. Bad contacts or shorts are especially difficult to diagnose. A failure at any point of the network cabling tends to prevent all communications. For this reason, 10BASE2 networks can be difficult to maintain and were often replaced by 10BASE-T networks, which (provided category 5 cable or better was used) also provided a good upgrade path to 100BASE-TX.

Comparisons to 10BASE-T
10BASE2 networks cannot generally be extended without breaking service temporarily for existing users and the presence of many joints in the cable also makes them very vulnerable to accidental or malicious disruption. There were proprietary systems that claimed to avoid these problems (e.g. SaferTap) but these never became widespread, possibly due to a lack of standardization. 10BASE-T can be extended by making a new connection to a hub. A fault in a one hub connection does not necessarily compromise other connections to the hub.

10BASE2 systems did have a number of advantages over 10BASE-T. No hub is required as with 10BASE-T, so the hardware cost was minimal, and wiring was particularly easy since only a single wire run is needed, which could be sourced from the nearest computer. These characteristics made 10BASE2 ideal for a small network of two or three machines, perhaps in a home where easily concealed wiring was an advantage. For a larger complex office network, the difficulties of tracing poor connections made it impractical. Unfortunately for 10BASE2, by the time multiple home computer networks became common, the format had already been practically superseded by 10BASE-T.

Comparisons to 10BASE5, use of AUI
10BASE2 uses RG-58A/U cable or similar for a maximum segment length of 185 m as opposed to the thicker RG-8-like cable used in 10BASE5 networks with a maximum length of 500 m. The RG-58 type wire used by 10BASE2 was inexpensive, smaller and much more flexible than the specialized RG-8 variant. 10BASE2 can also use RG-59 cable.

An Ethernet network interface controller (NIC) may include the 10BASE2 transceivers and thus directly provide a 10BASE2 BNC connector (that the T-connector plugs into), or it may offer an AUI connector that external transceivers (see Medium Attachment Unit) can connect to. These can be transceivers for 10BASE2, but also for 10BASE5 or 10BASE-T. Some NICs offer both BNC and AUI connectors, or other combinations including BNC and 10BASE-T. With multiple connections, only one connector is designed to be used at the same time.

title: 10BASE2


text:
10BASE5

10BASE5 (also known as thick Ethernet or thicknet) was the first commercially available variant of Ethernet. The technology was standardized in 1982 as IEEE 802.3. 10BASE5 uses a thick and stiff coaxial cable up to 500 m in length. Up to 100 stations can be connected to the cable using vampire taps and share a single collision domain with 10 Mbit/s of bandwidth shared among them. The system is difficult to install and maintain.

10BASE5 was superseded by much cheaper and more convenient alternatives: first by 10BASE2 based on a thinner coaxial cable (1985), and then, once Ethernet over twisted pair was developed, by 10BASE-T (1990) and its successors 100BASE-TX and 1000BASE-T. In 2003, the IEEE 802.3 working group deprecated 10BASE5 for new installations.

Name origination
The name 10BASE5 is derived from several characteristics of the physical medium. The 10 refers to its transmission speed of 10 Mbit/s. The BASE is short for baseband signaling (as opposed to broadband), and the 5 stands for the maximum segment length of 500 m.

Network design and installation
For its physical layer 10BASE5 uses cable similar to RG-8/U coaxial cable but with extra braided shielding. This is a stiff, 0.375 in diameter cable with an impedance of 50 ohms, a solid center conductor, a foam insulating filler, a shielding braid, and an outer jacket. The outer jacket is often yellow-to-orange fluorinated ethylene propylene (for fire resistance) so it often is called "yellow cable", "orange hose", or sometimes humorously "frozen yellow garden hose". 10BASE5 coaxial cables had a maximum length of 500 m. Up to 100 nodes could be connected to a 10BASE5 segment.

Transceiver nodes can be connected to cable segments with N connectors, or via a vampire tap, which allows new nodes to be added while existing connections are live. A vampire tap clamps onto the cable, a hole is drilled through the outer shielding, and a spike is forced to pierce the outer three layers and contact the inner conductor while other spikes bite into the outer braided shield. Care is required to keep the outer shield from touching the spike; installation kits include a "coring tool" to drill through the outer layers and a "braid pick" to clear stray pieces of the outer shield.

Transceivers should be installed only at precise 2.5-meter intervals. This distance was chosen to not correspond to the signal's wavelength; this ensures that the reflections from multiple taps are not in phase. These suitable points are marked on the cable with black bands. The cable is required to be one continuous run; T-connections are not allowed.

As is the case with most other high-speed buses, segments must be terminated at each end. For coaxial-cable-based Ethernet, each end of the cable has a 50 ohm resistor attached. Typically this resistor is built into a male N connector and attached to the cable's end just past the last device. With termination missing, or if there is a break in the cable, the signal on the bus will be reflected, rather than dissipated when it reaches the end. This reflected signal is indistinguishable from a collision and prevents communication.

Disadvantages
Adding new stations to the network is complicated by the need to pierce the cable accurately. The cable is stiff and difficult to bend around corners. One improper connection can take down the whole network and finding the source of the trouble is difficult.

title: 10BASE5


text:
1641

January–March

 * January 4 – The stratovolcano Mount Parker in the Philippines has a major eruption.
 * January 14 – The Battle of Malacca concludes with the Dutch East India Company ending Portuguese control of Malacca.
 * January 18 – The Junta de Braços (council of Estates) of the Principality of Catalonia, led by Pau Claris, proclaims the Catalan Republic under French protection.
 * February 16 – King Charles I of England gives his assent to the Triennial Act, reluctantly committing himself to parliamentary sessions of at least fifty days, every three years.
 * March 7 – King Charles I of England decrees that all Roman Catholic priests must leave England by April 7 or face being arrested and treated as traitors.
 * March 22 – The trial for high treason begins for Thomas Wentworth, 1st Earl of Strafford, director of England's Council of the North.
 * March 27
 * The Battle of Pressnitz begins between the Holy Roman Empire and Sweden.
 * The Siege of São Filipe begins in the Azores as the Portuguese Navy fights to drive the Spanish out. After almost 11 months, the Portuguese prevail on March 4, 1642.

April–June

 * April 7 – The deadline for Catholic priests to leave England expires. Among those who refuse to leave, Ambrose Barlow and William Ward become martyrs. Barlow surrenders on Easter Sunday, April 25, and is hanged on September 10; he will be canonized as a saint in 1970. Ward is caught on July 15 and executed on July 26.
 * April 15 – Aegidius Ursinus de Vivere is appointed by Pope Urban VIII to be the Roman Catholic Church's Patriarch of Jerusalem.
 * April 21 – England's House of Commons votes 204 to 59 in favor of the conviction for treason and the execution of the Earl of Strafford, and the House of Lords acquiesces. King Charles refuses to give the necessary royal assent.
 * April 25 – The Battle of Songjin begins in the modern-day North Korean city of Kimch'aek, at the time part of the Chinese Empire controlled by the Ming dynasty. The Ming, led by General Wu Sangui, defeat the Qing rebels.
 * April 30 – In Morocco, rebel leader and secessionist Sidi al-Ayachi is assassinated.
 * May 3 – The Protestation of 1641 is passed by England's Parliament, requiring all officeholders to swear an oath of allegiance to King Charles I and to the Church of England.
 * May 7 – England's House of Lords votes, 51 to 9, in favor of the execution of the Earl of Strafford for treason. In fear for his own safety, King Charles I signs Strafford's death warrant on May 10.
 * May 11 – The Long Parliament in England passes the "Act against Dissolving Parliament without its own Consent".
 * May 12 – Thomas Wentworth, 1st Earl of Strafford, former director of England's Council of the North, is publicly beheaded in London in front of a crowd of thousands of people.
 * May 24 – Providence Island in the Caribbean, settled by English Puritans and a haven for English pirates off the coast of modern-day Colombia, is captured in a joint operation of the Spanish Navy in an attack led by Don Francisco Díaz Pimienta, and the Portuguese Navy led by the Count of Castel-Melhor Sousa. The expedition takes 770 prisoners, 380 slaves and a fortune in plundered gold and silver.
 * June 1 – In Paris, representatives of Portugal and France sign a treaty of alliance.
 * June 2 – Bavarian and Spanish troops capture the town of Bad Kreuznach during the Thirty Years' War, 17 months after it had been taken in a French and Saxon attack.
 * June 12
 * In India, in the modern-day Rajasthan state, the Mughal Grand Vizier Abu'l-Hasan Asaf Khan is killed in a battle in Bundi against the armies of Nurpur, commanded by the Raja Jagat Singh. The elaborate Tomb of Asif Khan is constructed at Lahore (modern Pakistan) on orders of the Mughal Emperor Jahangir.
 * The Treaty of The Hague is signed between representatives of the Dutch Republic and the Kingdom of Portugal as a 10-year truce and alliance.
 * June 29 – The Battle of Wolfenbüttel takes place between a combined Swedish and French force against the Holy Roman Empire, with the Swedish-French Army driving back an Imperial assault.

July–September

 * July 5 – In England, the Long Parliament abolishes the Court of Star Chamber.
 * July 12 – Portugal and the Dutch Republic sign a Treaty of Offensive and Defensive Alliance at The Hague. The treaty is not respected by both parties, and as a consequence has no effect in the Portuguese colonies (Brazil and Angola) that are under Dutch rule.
 * August 10 – Charles I of England signs the Treaty of London ending the Bishops' Wars between England and Scotland.
 * September 14 – The Treaty of Péronne is signed between Honoré II, Prince of Monaco and France's King Louis XIII, guaranteeing the Grimaldi family the right to rule Monaco in return for the principality becoming a French protectorate.
 * September 18
 * In Germany, the Siege of Dorsten by the Holy Roman Empire ends after nine weeks with the surrender of the Landgraviate of Hesse-Kassel after the Hessians suffer 1,350 casualties.
 * In France, the siege of Bapaume ends with the surrender of the fortress by its Spanish occupiers.
 * September 23 – The English ship Merchant Royal sinks off Cornwall along with its cargo of 100000 lb of gold and 18 of its 58 crew. More than 380 years later, treasure seekers will still not have located the wreckage.

October–December

 * October 2 – Scottish politician John Campbell takes office as Lord Chancellor of Scotland and is given the title of the Earl of Loudoun by Charles I in his capacity as King of Scotland.
 * October 23 – Irish Rebellion of 1641 breaks out: Irish Catholic gentry, chiefly in Ulster, revolt against the English administration and Scottish settlers in Ireland.
 * October 24 – The Irish rebel Sir Felim O'Neill of Kinard issues the Proclamation of Dungannon.
 * November 4 – Battle of Cape St Vincent: A Dutch fleet, with Michiel de Ruyter as third in command, beats back a Spanish-Dunkirker fleet off the coast of Portugal.
 * November 22 – By a vote of 159 to 148, the Long Parliament of England passes the Grand Remonstrance, with 204 specific objections to King Charles I's absolutist tendencies, and calling for the King to expel all Anglican bishops from the House of Lords.
 * December 1 – The English Parliament presents the Grand Remonstrance to King Charles, who makes no response to it until Parliament has the document published and released to the general public.
 * December 7 – The bill for the Militia Ordinance is introduced by Arthur Haselrig, an anti-monarchist member of the House of Commons, proposing for the first time to allow Parliament to appoint its own military commanders without royal approval. King Charles, concerned that the legislation would allow parliament to create its own army, orders Haselrig arrested for treason. Parliament passes the Militia Ordinance on March 15.
 * December 16 – Pope Urban VIII announces the creation of 12 new cardinals of the Roman Catholic Church.
 * December 23 – King Charles replies to the Grand Remonstrance and refuses the demand for the removal of bishops from the House of Lords. Rioting breaks out in Westminster after the King's refusal is announced, and the 12 Anglican bishops stop attending meetings of the Lords.
 * December 27 – According to a journalist who witnesses the events, John Rushworth, the term "roundhead" is first used to describe supporters of the English Parliament who have challenged the authority of the monarchy. Rushworth writes later that during a riot on the 27th, one of the rioters, David Hide, draws his sword and, describing the short haircuts of the anti-monarchists, says that he would "cut the throat of those round-headed dogs that bawled against bishops."
 * December 30 – At the request of King Charles, John Williams, the Anglican Archbishop of York joins with 11 other bishops in disputing the legality of any legislation passed by the House of Lords during the time that the bishops were excluded. The House of Commons passes a resolution to have the 12 bishops arrested. King Charles, in turn, issues an order on January 3 to have five members of the House of Commons arrested for treason.

Date unknown

 * The Norwegian city of Kristiansand is founded by King Christian IV of Denmark-Norway.
 * The Dutch found a trading colony on Dejima, near Nagasaki, Japan.
 * The Massachusetts Bay Colony adopts a law making witchcraft a capital crime.
 * Moses Amyraut's De l'elevation de la foy et de l'abaissement de la raison en la creance des mysteres de la religion is published.
 * René Descartes' Meditations on First Philosophy is originally published.
 * The town of Falun, Sweden is given city rights by Queen Kristina.
 * A massive epidemic breaks out in northern and central China, just three years before the fall of the Ming dynasty. It races south down along the Grand Canal of China and the densely populated settlements there, from the northern terminus at Beijing, to the fertile Jiangnan region. In some local areas and towns it wipes out 90% of the local populace.

January–March

 * January 6 – Wolfgang Dietrich of Castell-Remlingen, German nobleman (d. 1709)
 * January 13 – Patrick Hume, 1st Earl of Marchmont, Scottish statesman (d. 1724)
 * January 18 – François-Michel le Tellier, Marquis de Louvois, French war minister (d. 1691)
 * February 2 – Claude de la Colombière, French Jesuit priest and saint (d. 1682)
 * February 3 – Christian Albert, Duke of Holstein-Gottorp, Duke of Schleswig-Holstein-Gottorp (1659–1695) (d. 1695)
 * February 4 – Jerolim Kavanjin, Croatian poet (d. 1714)
 * February 8
 * Richard Jones, 1st Earl of Ranelagh, Irish politician (d. 1712)
 * Robert Knox, English sea captain in the service of the British East India Company (d. 1720)
 * February 24 – Gabriel Tammelin, Lutheran clergyman (d. 1695)
 * March 14 – Hyeonjong of Joseon, 18th monarch of the Korean Joseon Dynasty (d. 1674)
 * March 19 – Abd al-Ghani al-Nabulsi, Muslim scholar (d. 1731)
 * March 29 – Johann Zahn, 17th-century German author of Oculus Artificialis Teledioptricus Sive Telescopium (d. 1707)

April–June

 * April 4 – Sir James Oxenden, 2nd Baronet, English politician (d. 1708)
 * April 8
 * Henry Sydney, 1st Earl of Romney, English politician and army officer (d. 1704)
 * (bapt.) – William Wycherley, English playwright (d. 1716)
 * April 15 – Robert Sibbald, Scottish physician and antiquarian (d. 1722)
 * May – Juan Núñez de la Peña, Spanish historian (d. 1721)
 * May 8 – Nicolaes Witsen, Mayor of Amsterdam, Netherlands (d. 1717)
 * May 16 – Dudley North, English economist, merchant and politician (d. 1691)
 * May 17 – Pierre Monier, French painter (d. 1703)
 * May 18 – Olimpia Giustiniani, Italian noblewoman (d. 1729)
 * May 28 – Johann Weikhard von Valvasor, Slovenian polymath (d. 1693)
 * May 31 – Patriarch Dositheos II of Jerusalem, Greek Orthodox Patriarch (d. 1707)
 * June 15 – Bernard de la Monnoye, French lawyer (d. 1728)
 * June 19 – Jan Claus, leading Quaker in Amsterdam (d. 1729)
 * June 28 – Marie Casimire Louise de La Grange d'Arquien, French-born Polish consort to King John III Sobieski (d. 1716)
 * June 29 – Pierre Cholonec, French Jesuit missionary and biographer in New France (d. 1723)
 * June 30 – Meinhardt Schomberg, 3rd Duke of Schomberg, English general (d. 1719)

July–September

 * July 9 – Jan Jansen Bleecker, Mayor of Albany, New York (d. 1732)
 * July 13 – Juan de Santiago y León Garabito, Spanish Catholic prelate, Bishop of Guadalajara and Bishop of Puerto Rico (d. 1694)
 * July 14 – William Boynton, English politician (d. 1689)
 * July 29 – Sir William Thomas, 1st Baronet, English Member of Parliament (d. 1706)
 * July 30 – Regnier de Graaf, Dutch physician and anatomist (d. 1673)
 * August – John Hathorne, American magistrate (d. 1717)
 * August 2 – Jacob Bobart the Younger, English botanist (d. 1719)
 * August 3 – Hildebrand Alington, 5th Baron Alington, Irish peer (d. 1723)
 * August 28 – Henry, Prince of Nassau-Dillenburg (1662–1701) (d. 1701)
 * September 1 – Jean Barbier d'Aucour, French lawyer and satirist (d. 1694)
 * September 5 – Robert Spencer, 2nd Earl of Sunderland, English diplomat (d. 1702)
 * September 7 – Tokugawa Ietsuna, Japanese Tokugawa shōgun (d. 1680)
 * September 16 – Julius Francis, Duke of Saxe-Lauenburg, Bohemian noble (d. 1689)
 * September 20 – Henri Arnaud, pastor of the Waldensians in Piedmont (d. 1721)
 * September 22 – Titus van Rijn, Dutch art dealer (d. 1668)
 * September 26 – Nehemiah Grew, English plant anatomist and physiologist (d. 1712)

October–December

 * October 1 – Hans Adam von Schöning, German general (d. 1696)
 * October 5 – Françoise-Athénaïs de Rochechouart de Mortemart, mistress of Louis XIV of France (d. 1707)
 * October 6 – Sir William Maynard, 1st Baronet, English politician (d. 1685)
 * October 10 – Wolfgang Printz, German composer (d. 1717)
 * October 14
 * Dorothea Maria of Saxe-Weimar, Duchess of Saxe-Zeitz, by marriage Duchess of Saxe-Zeitz (d. 1675)
 * Joachim Tielke, German musical instrument maker (d. 1719)
 * October 28 – Philip Skippon, English naturalist and Member of Parliament (d. 1691)
 * November 5 – Empress Xiaohuizhang, Qing Dynasty empress and consort of the Shunzhi Emperor of China (d. 1718)
 * November 10 – Edward Lake, English churchman (d. 1704)
 * November 14 – Albert Anton, Prince of Schwarzburg-Rudolstadt (1662–1710) (d. 1710)
 * November 17 – André, marquis de Nesmond, French naval commander (d. 1702)
 * November 23 – Anthonie Heinsius, Dutch statesman (d. 1720)
 * December 7 – Louis, Count of Armagnac, French noble (d. 1718)
 * December 11 – Jean-Louis Bergeret, holder of the 8th seat of the Académie française (d. 1694)
 * December 20 – Urban Hjärne, Swedish chemist (d. 1724)
 * December 29 – Pier Simone Fanelli, Italian painter (d. 1703)
 * date unknown
 * Pierre Allix, French Protestant clergyman (d. 1717)
 * Diego Ladrón de Guevara, viceroy of Peru (d. 1718)
 * Dodo von Knyphausen, German nobleman (d. 1698)

Deaths

 * January 3 – Jeremiah Horrocks, English astronomer (b. c. 1618)
 * January 9 – Gustavus Adolphus of the Palatinate, German noble (b. 1632)
 * January 11
 * Juan de Jáuregui, Spanish poet and painter (b. 1583)
 * Franciscus Gomarus, Dutch theologian (b. 1563)
 * February 15 – Sara Copia Sullam, Italian poet and writer (b. 1592)
 * February 17 – Krisztina Nyáry, Hungarian noblewoman (b. 1604)
 * February 24 – Francesco Usper, Italian composer (b. 1561)
 * February 27 – Pau Claris i Casademunt, Catalan ecclesiastic (b. 1586)
 * March 8 – Xu Xiake, Chinese adventurer and geographer (b. 1587)
 * March 14 – Adam, Count of Schwarzenberg, German politician (b. 1583)
 * March 23 – Claude Bernard, French priest (b. 1588)
 * April 6 – Domenico Zampieri (Domenichino), Italian painter (b. 1581)
 * April 13 – Richard Montagu, English clergyman (b. 1577)
 * April 27 – Wilhelm von Rath, German soldier and scholar (b. 1585)
 * May 10 – Johan Banér, Swedish soldier (b. 1596)
 * May 12 – Thomas Wentworth, 1st Earl of Strafford, English statesman (b. 1593)
 * June 1 – Carlo Emanuele Pio di Savoia, Italian Catholic cardinal (b. 1585)
 * July 4
 * István Esterházy Hungarian noble (b. 1616)
 * Pedro Teixeira, Portuguese explorer
 * July 6
 * Livia della Rovere, Italian noble (b. 1585)
 * Louis, Count of Soissons (b. 1604)
 * July 8 – Balthasar I Moretus, Flemish printer (b. 1574)
 * July 13 – Nicolaes le Febure, Dutch Golden Age member of the Haarlem schutterij (b. 1589)
 * July 21 – Thomas Mun, English writer on economics (b. 1571)
 * July 24 – Giovanni Francesco Guidi di Bagno, Italian cardinal (b. 1578)
 * August 4 – Otto III, Duke of Brunswick-Harburg (b. 1572)
 * August 9 – Augustine Baker, Welsh Benedictine mystic (b. 1575)
 * August 16 – Thomas Heywood, English playwright (b. c. 1573)
 * August 26 – Jean-Jacques Bouchard, 17th-century French writer (b. 1606)
 * September 10 – Ambrose Barlow, English Catholic martyr (b. 1585) (executed)
 * September 12 – John Upton, English politician (b. 1590)
 * October 3 – Étienne Martellange, French architect (b. 1569)
 * October 31 – Cornelis Jol, Dutch naval commander and privateer (b. 1597)
 * November 9
 * Cardinal-Infante Ferdinand of Austria, Governor of the Netherlands and Bishop of Toledo (b. c. 1609)
 * Maren Spliid, Danish alleged witch (b. c. 1600) (executed)
 * November 11 – Christopher Clitherow, Lord Mayor of London and Member of Parliament (b. 1578)
 * November 12 – Philipp Ludwig III, Count of Hanau-Münzenberg (1638–1641) (b. 1632)
 * November 26 – Hedwig of Denmark, Danish princess (b. 1581)
 * December 3 – John Percy, English priest (b. 1569)
 * December 9 – Sir Anthony van Dyck, Flemish painter (b. 1599)
 * December 22 – Maximilien de Béthune, Duke of Sully, 2nd Prime Minister of France (b. 1560)
 * December 27 – Francis van Aarssens, Dutch diplomat (b. 1572)

Date unknown

 * Estêvão de Brito, Portuguese composer (b. c. 1570)
 * Arthur Johnston, Scottish physician and poet (b. c. 1579)
 * Mukai Shogen Tadakatsu, Japanese admiral (b. 1582)
 * Harjol, Chinese concubine of Hong Taiji (b. 1609)

title: 1641


text:
Ethernet over twisted pair

Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.

Early Ethernet used various grades of coaxial cable, but in 1984, StarLAN showed the potential of simple unshielded twisted pair. This led to the development of 10BASE-T and its successors 100BASE-TX, 1000BASE-T, 10GBASE-T and 40GBASE-T, supporting speeds of 10 and 100 megabit per second, then 1, 10 and 40 gigabit per second respectively.

Two new variants of 10 megabit per second Ethernet over a single twisted pair, known as 10BASE-T1S and 10BASE-T1L, were standardized in IEEE Std 802.3cg-2019. 10BASE-T1S has its origins in the automotive industry and may be useful in other short-distance applications where substantial electrical noise is present. 10BASE-T1L is a long-distance Ethernet, supporting connections up to 1 km in length. Both of these standards are finding applications implementing the Internet of things. 10BASE-T1S is a direct competitor of CAN XL in the automotive space and includes a PHY-Level Collision Avoidance scheme (PLCA).

The earlier standards use 8P8C modular connectors, and supported cable standards range from Category 3 to Category 8. These cables typically have four pairs of wires for each connection, although early Ethernet used only two of the pairs. Unlike the earlier -T standards, the -T1 interfaces were designed to operate over a single pair of conductors and introduce the use of two new connectors referred to as IEC 63171-1 and IEC 63171-6.

History
The first two early designs of twisted-pair networking were StarLAN, standardized by the IEEE Standards Association as IEEE 802.3e in 1986, at one megabit per second, and LattisNet, developed in January 1987, at 10 megabit per second. Both were developed before the 10BASE-T standard (published in 1990 as IEEE 802.3i) and used different signaling, so they were not directly compatible with it.

In 1988, AT&T released StarLAN 10, named for working at 10 Mbit/s. The StarLAN 10 signaling was used as the basis of 10BASE-T, with the addition of link beat to quickly indicate connection status.

Using twisted-pair cabling in a star topology addressed several weaknesses of the previous Ethernet standards:
 * Twisted-pair cables were already in use for telephone service and were already present in many office buildings, lowering the overall cost of deployment
 * The centralized star topology was also already often in use for telephone service cabling, as opposed to the bus topology required by earlier Ethernet standards
 * Using point-to-point links was less prone to failure and greatly simplified troubleshooting compared to a shared bus
 * Exchanging cheap repeater hubs for more advanced switching hubs provided a viable upgrade path
 * Mixing different speeds in a single network became possible with the arrival of Fast Ethernet
 * Depending on cable grades, subsequent upgrading to Gigabit Ethernet or faster could be accomplished by replacing the network switches

Although 10BASE-T is rarely used as a normal-operation signaling rate today, it is still in wide use with network interface controllers in wake-on-LAN power-down mode and for special, low-power, low-bandwidth applications. 10BASE-T is still supported on most twisted-pair Ethernet ports with up to Gigabit Ethernet speed.

Naming
The common names for the standards derive from aspects of the physical media. The leading number (10 in 10BASE-T) refers to the transmission speed in Mbit/s. BASE denotes that baseband transmission is used. The T designates twisted-pair cable. Where there are several standards for the same transmission speed, they are distinguished by a letter or digit following the T, such as TX or T4, referring to the encoding method and number of lanes.

Cabling

Most Ethernet cables are wired straight-through (pin 1 to pin 1, pin 2 to pin 2, and so on). In some instances, the crossover form (receive to transmit and transmit to receive) may still be required.

Cables for Ethernet may be wired to either the T568A or T568B termination standards at both ends of the cable. Since these standards differ only in that they swap the positions of the two pairs used for transmitting and receiving, a cable with T568A wiring at one end and T568B wiring at the other results in a crossover cable.

A 10BASE-T or 100BASE-TX host uses a connector wiring called medium dependent interfaces (MDI), transmitting on pins 1 and 2 and receiving on pins 3 and 6 to a network device. An infrastructure node (a hub or a switch) accordingly uses a connector wiring called MDI-X, transmitting on pins 3 and 6 and receiving on pins 1 and 2. These ports are connected using a straight-through cable so each transmitter talks to the receiver on the other end of the cable.

Nodes can have two types of ports: MDI (uplink port) or MDI-X (regular port, 'X' for internal crossover). Hubs and switches have regular ports. Routers, servers and end hosts (e.g. personal computers) have uplink ports. When two nodes having the same type of ports need to be connected, a crossover cable may be required, especially for older equipment. Connecting nodes having different types of ports (i.e., MDI to MDI-X and vice versa) requires a straight-through cable. Thus connecting an end host to a hub or switch requires a straight-through cable. Some older switches and hubs provided a button to allow a port to act as either a normal (regular) or an uplink port, i.e. using MDI-X or MDI pinout, respectively.

Many modern Ethernet host adapters can automatically detect another computer connected with a straight-through cable and then automatically introduce the required crossover if needed; if neither of the adapters has this capability, then a crossover cable is required. Most newer switches have auto MDI-X on all ports allowing all connections to be made with straight-through cables. If both devices being connected support 1000BASE-T according to the standards, they will connect regardless of whether a straight-through or crossover cable is used.

A 10BASE-T transmitter sends two differential voltages, +2.5 V or −2.5 V. A 100BASE-TX transmitter sends three differential voltages, +1 V, 0 V, or −1 V. Unlike earlier Ethernet standards using broadband and coaxial cable, such as 10BASE5 (thicknet) and 10BASE2 (thinnet), 10BASE-T does not specify the exact type of wiring to be used but instead specifies certain characteristics that a cable must meet. This was done in anticipation of using 10BASE-T in existing twisted-pair wiring systems that did not conform to any specified wiring standard. Some of the specified characteristics are attenuation, characteristic impedance, propagation delay, and several types of crosstalk. Cable testers are widely available to check these parameters to determine if a cable can be used with 10BASE-T. These characteristics are expected to be met by 100 meters of 24-gauge unshielded twisted-pair cable. However, with high-quality cabling, reliable cable runs of 150 meters or longer are often achievable and are considered viable by technicians familiar with the 10BASE-T specification.

100BASE-TX follows the same wiring patterns as 10BASE-T, but is more sensitive to wire quality and length, due to the higher bit rates.

1000BASE-T uses all four pairs bi-directionally using hybrid circuits and cancellers. Data is encoded using 4D-PAM5; four dimensions using pulse-amplitude modulation (PAM) with five voltages, −2 V, −1 V, 0 V, +1 V, and +2 V. While +2 V to −2 V may appear at the pins of the line driver, the voltage on the cable is nominally +1 V, +0.5 V, 0 V, −0.5 V and −1 V.

100BASE-TX and 1000BASE-T were both designed to require a minimum of category 5 cable and also specify a maximum cable length of 100 m. Category 5 cable has since been deprecated and new installations use Category 5e.

Shared cable
10BASE-T and 100BASE-TX require only two pairs (pins 1–2, 3–6) to operate. Since common Category 5 cable has four pairs, it is possible to use the spare pairs (pins 4–5, 7–8) in 10- and 100-Mbit/s configurations for other purposes. The spare pairs may be used for power over Ethernet (PoE), for two plain old telephone service (POTS) lines, or for a second 10BASE-T or 100BASE-TX connection. In practice, great care must be taken to separate these pairs as 10/100-Mbit/s Ethernet equipment electrically terminates the unused pins ("Bob Smith Termination"). Shared cable is not an option for Gigabit Ethernet as 1000BASE-T requires all four pairs to operate.

Single-pair
In addition to the more computer-oriented two and four-pair variants, the 10BASE-T1, 100BASE-T1 and 1000BASE-T1 single-pair Ethernet (SPE) physical layers are intended for industrial and automotive applications or as optional data channels in other interconnect applications. The distances that single pair operates at full duplex depends on the speed: 1000m (1km) with 802.3cg-2019 10BASE-T1L; 15 m with 100BASE-T1 (link segment type A); up to 40 m using 1000BASE-T1 link segment type B with up to four in-line connectors. Both physical layers require a balanced twisted pair with an impedance of 100 Ω. The cable must be capable of transmitting 600 MHz for 1000BASE-T1 and 66 MHz for 100BASE-T1. 2.5 Gb/s, 5 Gb/s, and 10 Gb/s over a 15 m single pair is standardized in 802.3ch-2020. In June 2023, 802.3cy added 25 Gb/s speeds at lengths up to 11 m.

Similar to PoE, Power over Data Lines (PoDL) can provide up to 50 W to a device.

Connectors

 * 8P8C modular connector: For stationary uses in controlled environments, from homes to datacenters, this is the dominant connector. Its fragile locking tab otherwise limits its suitability and durability. Bandwidths supporting up to Cat 8 cabling are defined for this connector format.
 * M12X: This is the M12 connector designated for Ethernet, standardized as IEC 61076-2-109. It is a 12 mm metal screw that houses 4 shielded pairs of pins. Nominal bandwidth is 500 MHz (Cat 6A). The connector family is used in chemically and mechanically harsh environments such as factory automation and transportation. Its size is similar to the modular connector.
 * ix Industrial: This connector is designed to be small yet strong. It has 10 pins and a different locking mechanism than the modular connector. Standardized as IEC 61076-3-124, its nominal bandwidth is 500 MHz (Cat 6A).
 * Single-pair Ethernet defines its own connectors:
 * IEC 63171-1 "LC": This is a 2-pin connector with a similar locking tab to the modular connector, if thicker.
 * IEC 63171-6 "industrial": This standard defines 5 2-pin connectors that differ in their locking mechanisms and one 4-pin connector with dedicated pins for power. The locking mechanisms range from a metal locking tab to M8 and M12 connectors with screw or push-pull locking. The 4-pin connector is only defined with M8 screw locking.

Autonegotiation and duplex
Ethernet over twisted-pair standards up through Gigabit Ethernet define both full-duplex and half-duplex communication. However, half-duplex operation for gigabit speed is not supported by any existing hardware. Higher speed standards, 2.5GBASE-T up to 40GBASE-T running at 2.5 to 40 Gbit/s, consequently define only full-duplex point-to-point links which are generally connected by network switches, and do not support the traditional shared-medium CSMA/CD operation.

Many different modes of operations (10BASE-T half-duplex, 10BASE-T full-duplex, 100BASE-TX half-duplex, etc.) exist for Ethernet over twisted pair, and most network adapters are capable of different modes of operation. Autonegotiation is required in order to make a working 1000BASE-T connection.

When two linked interfaces are set to different duplex modes, the effect of this duplex mismatch is a network that functions much more slowly than its nominal speed. Duplex mismatch may be inadvertently caused when an administrator configures an interface to a fixed mode (e.g. 100 Mbit/s full-duplex) and fails to configure the remote interface, leaving it set to autonegotiate. Then, when the auto-negotiation process fails, half-duplex is assumed by the autonegotiating side of the link.

title: Ethernet over twisted pair


text:
1410

Year 1410 (MCDX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar.

January–December

 * March 25 – The first of the Yongle Emperor's campaigns against the Mongols is launched, leading to the fall of Öljei Temür Khan.
 * March 29 – The Aragonese capture Oristano, capital of the Giudicato di Arborea in Sardinia.
 * June 15 – Ottoman Interregnum: Süleyman Çelebi defeats his brother Musa Çelebi outside the Byzantine capital, Constantinople.
 * July 11 – Ottoman Interregnum: Süleyman Çelebi defeats his brother Musa Çelebi outside the Ottoman capital, Edirne.
 * July 15 – Battle of Grunwald (Žalgiris), also known as Battle of Tannenberg: Polish and Lithuanian forces under cousins Jogaila and Vytautas the Great decisively defeat the forces of the Teutonic Knights, whose power is broken.

Date unknown

 * Jan Hus is excommunicated by the Archbishop of Prague.
 * Antipope John XXIII is elected.
 * Construction begins on Castle Woerden in the Netherlands.
 * The Prague Astronomical Clock (also known as Prague Orloj) is built by Mikuláš of Kadaň and Jan Šindel in Prague, the capital of the Czech Republic.

Births

 * January 30 – William Calthorpe, English knight (d. 1494)
 * July 14 – Arnold, Duke of Guelders, Duke of Guelders (1423–1465 and 1471–1473) (d. 1473)
 * August 1 – John IV, Count of Nassau-Siegen (1442–1475) (d. 1475)
 * date unknown
 * Masuccio Salernitano, Italian poet (d. 1475)
 * William Sinclair, 1st Earl of Caithness (d. 1484)
 * probable
 * Johannes Ockeghem, Dutch composer (d. 1497)
 * Ólöf Loftsdóttir, politically active Icelandic woman (d. 1479)
 * Conrad Paumann, German organist and composer (d. 1473)
 * Vecchietta, Sienese painter, sculptor and architect (d. 1480)

Deaths

 * March 5 – Matthew of Kraków, Polish reformer (b. 1335)
 * March 16 – John Beaufort, 1st Earl of Somerset (b. 1373)
 * May 3 – Antipope Alexander V, (b. 1339)
 * May 18 – Rupert of Germany, Count Palatine of the Rhine (b. 1352)
 * May 31 – Martin of Aragon (b. 1356)
 * July 15 – Ulrich von Jungingen, German Grand Master of the Teutonic Knights (in battle) (b. 1360)
 * August – Matthew I of Constantinople
 * August 10 – Louis II, Duke of Bourbon (b. 1337)
 * date unknown
 * Margareta Dume, influential Swedish-Finnish noble
 * John Badby, English martyr

title: 1410


text:
AD 13

AD 13 (XIII) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silius and Plancus (or, less frequently, year 766 Ab urbe condita). The denomination AD 13 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Emperor Augustus initiates his third census of the Roman Empire after 20 years.
 * Abgarus of Edessa is reinstalled as king of Osroene.
 * The Senate passes a senatus consultum restricting the reduced Vigintisexviri to the Ordo Equester.

China

 * Last year (3rd) of Shijianguo era of the Chinese Xin Dynasty (considered the lucky number of those from the Chinese Xin Dynasty).

Arts and sciences

 * Strabo publishes his book on the shape of the Earth.
 * Ovid publishes books 1-3 of his Epistulae ex Ponto.

Births

 * Casperius Aelianus, Roman praetorian prefect (d. AD 98)
 * Gaius Silius, Roman politician (d. AD 48)

Deaths

 * Quintus Pedius, Roman (deaf) painter (approximate date)
 * Wang Zhengjun, Chinese empress (b. 71 BC)

title: AD 13


text:
AD 15

AD 15 (XV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Caesar and Flaccus (or, less frequently, year 768 Ab urbe condita). The denomination AD 15 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Early (approx.) – Emona (on the site of modern-day Ljubljana) is founded by Legio XV Apollinaris.
 * May – As part of his campaign against the Germanic peoples, Germanicus captures Thusnelda, wife of Arminius.
 * Summer – Germanicus launches a two-pronged attack from Vetera and Moguntiacum. On his return journey, he recaptures the aquila of Legio XIX and visits the battlefield of the Teutoburg Forest. Germanicus arranges the burial for the remains of Varus' army.
 * Varna (Odessus), on the Bulgarian Black Sea Coast, is annexed to the Roman province of Moesia.
 * In Rome, the election of magistrates passes from the people to the Emperor and the Senate.
 * The river Tiber floods parts of Rome.

Arts and sciences

 * Nicolaus of Damascus writes a biography of the Emperor Augustus (Bios Kaisaros).

Births

 * September 24 – Vitellius, Roman emperor (d. AD 69)
 * November 6 – Agrippina the Younger, Roman empress (d. AD 59)
 * Apollonius of Tyana, Greek philosopher (d. c. AD 97)
 * Ennia Thrasylla, Roman noblewoman (d. AD 38)
 * Lollia Paulina, Roman empress (d. AD 49)
 * Lucius Verginius Rufus, Roman consul (d. AD 97)

Deaths

 * Lucius Seius Strabo, Roman praetorian prefect (b. 46 BC)

title: AD 15


text:
AD 16

AD 16 (XVI) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Taurus and Libo (or, less frequently, year 769 Ab urbe condita). The denomination AD 16 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * A Roman army of 50,000 men commanded by Germanicus gains a great victory at Idistaviso, defeating the German war chief Arminius, and recovering the lost eagles of Varus' legions.
 * Germanicus employs the North Sea fleet to avoid dangerous rivers, embarking an army in the Rhine Delta, aboard circa 1,000 ships. He defeats the Germans at the Amisius river estuary and the Weser, but during its return, the Roman fleet is partially destroyed by storms.
 * Vonones, the beleaguered king of Armenia, is summoned to Syria, by Roman governor Creticus Silanus.

Arts and sciences

 * Ovid's "Epistulae ex Ponto" appears.

Births

 * September 16 – Julia Drusilla, daughter of Germanicus and Agrippina the Elder (d. AD 38)
 * Claudius Drusus, son of Claudius and Plautia Urgulanilla (approximate date)
 * Decimus Junius Silanus Torquatus, Roman consul (d. AD 64)

Deaths

 * September 13 – Marcus Scribonius Libo, Roman senator (forced to commit suicide)
 * Clemens, Roman slave and impostor (executed by Tiberius)
 * Scribonia, second wife of Caesar Augustus (approximate date)

title: AD 16


text:
AD 17

AD 17 (XVII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Flaccus and Rufus (or, less frequently, year 770 Ab urbe condita). The denomination AD 17 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * May 26 – Germanicus returns to Rome as a conquering hero; he celebrates a triumph for his victories over the Cherusci, Chatti and other Germanic tribes west of the Elbe.
 * Emperor Tiberius sends Germanicus to the east, in order to lead a military campaign against Parthia.
 * Cappadocia (Asia Minor) becomes a Roman province.
 * Lucius Aelius Sejanus becomes Praetorian prefect.

Africa

 * Tacfarinas, Numidian deserter from the Roman army, begins a guerrilla war against the Romans. He leads his own Musulamii tribe and a coalition of Berbers, attacking the Limes Tripolitanus, a fortified zone (limes) of the Roman Empire in Africa.

Judea

 * Herod Antipas, son of Herod the Great, builds the city Tiberias on the western shore of the Sea of Galilee, in honor of Tiberius.

Asia Minor

 * An earthquake in Anatolia destroys the city of Sardis and damages several other cities.

Deaths

 * Antiochus III, King of Commagene
 * Archelaus, king of Cappadocia
 * Gaius Julius Hyginus, Roman Latin writer
 * Livy, Roman historian
 * Lucius Vipstanus Gallus, Roman senator
 * Ovid, Roman poet (or AD 18)

title: AD 17


text:
AD 18

AD 18 (XVIII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Caesar (or, less frequently, year 771 Ab urbe condita). The denomination AD 18 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * A vexillatio (sub-unit or detachment) of Legio III Augusta is destroyed by an ambush in Africa.

Syria

 * Winter – Germanicus Caesar arrives in Syria, as new commander-in-chief for the Roman East.
 * Gnaeus Calpurnius Piso, governor of Syria, ignores the order of Germanicus to send Syrian-based legions, including Legio VI Ferrata and Legio X Fretensis, to Armenia to back him in his planned coronation of Artaxias III.

Parthia

 * Germanicus concludes a peace treaty with Artabanus II of Parthia, in which he is recognized as king and friend of Rome.

China

 * After a flooding of the Yellow River in China, farmers are forced to rebel. Emperor Wang Mang reacts by sending an army (some 100,000 men) against the agrarian rebels. The rebel leaders, concerned that during battle it will become impossible to tell friend from foe, order that their men color their eyebrows red – and this is where the name Chimei ("The Red Eyebrows") comes from.

Korea

 * Daemusin becomes ruler of the Korean kingdom of Goguryeo.

India

 * In India, the Indo-Parthians control Taxila.

Births

 * Julia Livilla, daughter of Germanicus and Agrippina the Elder (approximate date) (d. AD 41)

Deaths

 * Crinagoras, Greek epigrammatist (b. 70 BC)
 * Herod Archelaus, Jewish ruler (ethnarch) (b. 23 BC)
 * Mother Lü, rebel leader against the Xin dynasty
 * Publius Ovidius Naso, Roman poet (or AD 17)
 * Yang Xiong, Chinese philosopher (b. 53 BC)
 * Yuri, Korean ruler of Goguryeo

title: AD 18


text:
AD 20

AD 20 (XX) was a leap year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Marcus Valerius Messalla Barbatus and Cotta (or, less frequently, year 773 Ab urbe condita). The denomination 20 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Galba, the future emperor, is a Roman praetor.
 * Emperor Tiberius is forced to order an investigation and a public trial in the Roman Senate, for the murder of Germanicus. Fearing he will be found guilty, Gnaeus Calpurnius Piso commits suicide.

Deaths

 * Gnaeus Calpurnius Piso, Roman statesman and governor of Syria (b. 44 BC)
 * Vipsania Agrippina, wife of Gaius Asinius Gallus and former wife of Tiberius (b. 36 BC)
 * Amanitore, Nubian Queen Regnant of the Kushitic Kingdom of Meroë

title: AD 20


text:
AD 21

AD 21 (XXI) was a common year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Tiberius and Drusus (or, less frequently, year 774 Ab urbe condita). The denomination AD 21 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * The Aedui revolt under Julius Florus and Julius Sacrovir; the revolt is suppressed by Gaius Silius.
 * Emperor Tiberius is a Roman Consul for the fourth time.

 * The Romans create a buffer state in the territory of the Quadi, in southern Slovakia.
 * Barracks are constructed for the Praetorian Guard, on the Quirinal (located on the Seven Hills of Rome).

Korea

 * King Daeso of Dongbuyeo is killed in battle against the armies of Goguryeo, led by its third ruler, King Daemusin.

Art and Science

 * The manufacture of pens and metal writing tools begins in Rome (approximate date).

Deaths

 * Arminius, Germanic military leader (b. 18/17 BC)
 * Clutorius Priscus, Roman poet (b. c. 20 BC)
 * Daeso of Dongbuyeo, Korean king (b. 60 BC)
 * Marcus Valerius Messalla Barbatus, Roman consul (b. 11 BC)
 * Publius Sulpicius Quirinius, Roman governor (b. c. 51 BC)
 * Wang (or Xiaomu), Chinese empress of the Xin Dynasty

title: AD 21


text:
AD 22

AD 22 (XXII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Agrippa and Galba (or, less frequently, year 775 Ab urbe condita). The denomination AD 22 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Drusus Julius Caesar receives the tribunicia potestas (tribunician power).

Births

 * Valeria Messalina, third wife of Emperor Claudius (d. 48 AD)

Deaths

 * Daeso, emperor of Dongbuyeo (b. 60 BC)
 * Gaius Ateius Capito, Roman jurist and suffect consul (b. c. 30 BC)
 * Junia Tertia, wife of Gaius Cassius Longinus (b. c. 75 BC)

title: AD 22


text:
AD 23

AD 23 (XXIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Pollio and Vetus (or, less frequently, year 776 Ab urbe condita). The denomination AD 23 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Greek geographer Strabo publishes Geographica, a work covering the world known to the Romans and Greeks at the time of Emperor Augustus – it is the only such book to survive from the ancient world.
 * Emperor Tiberius' son Drusus Julius Caesar dies. From that point forward, he seems to lose interest in the Empire and occupies himself with the pursuit of pleasure.
 * Lucius Aelius Sejanus begins to dominate the Roman Senate and Tiberius, after the death of Drusus.

China

 * Liu Xuan, a descendant of the Han dynasty royal family and leader of insurgents against the Xin dynasty, proclaims himself emperor against Wang Mang.
 * July – After being under siege for two months, about 19,000 insurgents under Liu Xiu defeat 450,000 of Wang Mang's troops in the Battle of Kunyang, ushering in the fall of Wang Mang's Xin dynasty and restoration of the Han dynasty.
 * October 6 – Emperor Liu Xuan's forces kill Wang Mang at the end of a three-day siege.

Births

 * Pliny the Elder, Roman scientist and writer (d. 79 AD)

Deaths

 * September 14 – Drusus Julius Caesar, son of Emperor Tiberius (b. 14 BC)
 * October 6 – Wang Mang, Chinese emperor of the Xin dynasty (b. c. 45 BC)
 * Juba II, king of Mauretania (b. c. 50 BC)
 * Liu Xin, Chinese astronomer, mathematician and politician (b. c. 50 BC)
 * Liu Yan, Chinese general and politician
 * Servius Cornelius Lentulus Maluginensis, Roman statesman
 * Wang, Chinese empress of the Xin dynasty (b. 8 BC)

title: AD 23


text:
AD 24

AD 24 (XXIV) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Cethegus and Varro (or, less frequently, year 777 Ab urbe condita). The denomination AD 24 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * The Roman war against Numidia and Mauretania ends with their annexation.
 * Tacfarinas' revolt in Africa is repressed.
 * The Senate expels actors from Rome.

Korea

 * King Yuri ascends to the throne as ruler of Silla (Korea).

Africa

 * The Masinissa line of the rulers of Carthage ends.

Deaths

 * Gaius Silius, Roman general and consul
 * Lucius Calpurnius Piso, Roman consul
 * Namhae, king of Silla
 * Strabo, Greek geographer and historian
 * Tacfarinas, Numidian military leader
 * Wang Lang, Chinese emperor

title: AD 24


text:
AD 27

AD 27 (XXVII) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Piso and Frugi (or, less frequently, year 780 Ab urbe condita). The denomination AD 27 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * A fire breaks out in Rome.
 * A poorly built amphitheatre in Fidenae collapses, killing 20,000 of the 50,000 spectators.
 * Using the dates and ranges listed in the Gospel of Luke, this year can be established as when John the Baptist begins preaching in the Jordan. It is also likely that Jesus was baptised by John in the final months of this year before his temptation and the first of three Passovers listed in the Gospel of John.
 * An Arc of Triumph is erected in Rimini, in honor of the former Emperor Augustus.

Religion

 * Possible date of the Baptism of Jesus by John the Baptist (another possibility is AD 29).

Births

 * Herod Agrippa II, king of Judea
 * Petronius, Roman writer and suffect consul (d. AD 66)
 * Wang Chong, Chinese astronomer and philosopher (d. AD 100)

Deaths

 * Publius Quinctilius Varus the Younger, Roman nobleman (b. AD 4)

title: AD 27


text:
AD 28

AD 28 (XXVIII) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silanus and Nerva (or, less frequently, year 781 Ab urbe condita). The denomination AD 28 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Germania

 * Roman legions in Germania are transported by fleet to the fortress of Flevum on the Rhine, to operate against the rebellious Frisians.
 * The Frisians negotiate a treaty with the Roman Empire at the River Rhine, avoiding conquest.

Korea

 * King Daru of Baekje succeeds to the throne of Baekje in the Korean peninsula.

Judea

 * According to the Gospel of Luke (Luke 3:1-2), the ministries of John the Baptist and Jesus begin at the earliest in this year, and more likely in AD 29.

Births

 * June 15 – Ming of Han, Chinese emperor (d. AD 75)
 * Julia Berenice, Jewish client queen of Judea
 * Silius Italicus, Roman consul and epic poet

Deaths

 * Onjo of Baekje, Korean king

title: AD 28


text:
AD 29

AD 29 (XXIX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Geminus and Geminus (or, less frequently, year 782 Ab urbe condita). The denomination AD 29 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Roman Empire

 * Agrippina the Elder is exiled to the island of Pandataria, and her sons (except Caligula) are imprisoned by Lucius Aelius Sejanus.
 * Aulus Plautius, later military leader of the invasion of Britain under Emperor Claudius, becomes suffect consul alongside Lucius Nonius Asprenas.

Religion

 * According to the Gospel of Luke (Luke 3:1-2), the ministries of John the Baptist and Jesus probably began in this year. Jesus is baptized by John the Baptist.
 * Jesus executed by crucifixion, according to Roman Catholic tradition and Tertullian's chronology.

Deaths

 * Gaius Fufius Geminus, Roman plebeian tribune and consul
 * Julia the Younger, granddaughter of Augustus (b. 19 BC)
 * Livia, wife of Augustus and mother of Tiberius (b. 58 BC)
 * Jesus (b. 5 BC)

title: AD 29


text:
AD 30

AD 30 (XXX) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Vinicius and Longinus (or, less frequently, year 783 Ab urbe condita). The denomination AD 30 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

South Asia

 * The Kushan Empire is founded (approximate date).

Roman Empire

 * Agrippina the Elder (the wife of Germanicus) and two of her sons, Nero Julius Caesar and Drusus Caesar, are arrested and exiled on orders of Lucius Aelius Sejanus (the prefect of the Praetorian Guard), and later starved to death in suspicious circumstances. In Sejanus's purge of Agrippina the Elder and her family, her son Caligula, and her three daughters, Agrippina the Younger, Julia Drusilla and Julia Livilla are the only survivors.
 * Phaedrus translates Aesop's fables, and composes some of his own.
 * Velleius Paterculus writes the general history of the countries known in Antiquity.

Religion

 * 7 April (Good Friday) – Jesus is crucified (according to one dating scheme).  He is later reported alive by his disciples.

Births

 * November 8 – Nerva, Roman emperor (d. AD 98)
 * Jia Kui, Chinese Confucian philosopher (d. AD 101)
 * Mobon of Goguryeo, Korean king (d. AD 53)
 * Poppaea Sabina, second wife of Nero (d. AD 65)
 * Quintus Petillius Cerialis, Roman general

Deaths

 * April 7 – Jesus of Nazareth, (possible date of the crucifixion)  (born circa 4 BC) The other possible dates also supported by scholarly consensus among a survey of 100 published scholarly biblical statements are April 6, AD 31 and April 3, AD 33.
 * Shammai, Jewish Talmudic scholar (b. 50 BC)

title: AD 30


text:
16550 UART

The 16550 UART (universal asynchronous receiver-transmitter) is an integrated circuit designed for implementing the interface for serial communications. The corrected -A version was released in 1987 by National Semiconductor. It is frequently used to implement the serial port for IBM PC compatible personal computers, where it is often connected to an RS-232 interface for modems, serial mice, printers, and similar peripherals. It was the first serial chip used in the IBM PS/2 line, which were introduced in 1987.

The part was originally made by National Semiconductor. Similarly numbered devices, with varying levels of compatibility with the original National Semiconductor part, are made by other manufacturers. A UART function that is register-compatible with the 16550 is usually a feature of multifunction I/O cards for IBM PC-compatible computers and may be integrated on the motherboard of other compatible computers.

Replacement of the factory-installed 8250 UART was a common upgrade for owners of IBM PC, XT, and compatible computers when high-speed modems became available. Above 9600 baud, owners discovered that the serial ports of the computers were not able to handle a continuous flow of data without losing characters. Exchange of the 8250 (having only a one-byte received data buffer) with a 16550—and occasionally patching or setting system software to be aware of the FIFO feature of the new chip—improved the reliability and stability of high-speed connections.

Features
Main features of the 16550 include:
 * The ability to convert data from serial to parallel, and from parallel to serial, using shift registers.
 * An on-chip bit rate (baud rate) generator to control transmit and receive data rate.
 * Handshake lines for control of an external modem, controllable by software.
 * An interrupt function to the host microprocessor.
 * An on-chip FIFO buffer for both incoming and outgoing data; this gives the host system more time to respond to an interrupt generated by the UART, without loss of data.

Both the computer hardware and software interface of the 16550 are backward compatible with the earlier 8250 UART and 16450 UART. The current version (since 1995) by Texas Instruments which bought National Semiconductor is called the 16550D.

The 16550A and newer is pin-compatible with the 16450, but the Microsoft diagnostics program (MSD) supplied with MS-DOS 6.x, Windows 9x, Windows Me, and Windows 2000 often report the 16450 chip as an 8250 chip.

The FIFO buffer

One drawback of the earlier 8250 UARTs and 16450 UARTs was that interrupts were generated for each byte received. This generated high rates of interrupts as transfer speeds increased. More critically, with only a 1-byte buffer there is a genuine risk that a received byte will be overwritten if interrupt service delays occur. To overcome these shortcomings, the 16550 series UARTs incorporated a 16-byte FIFO buffer with a programmable interrupt trigger of 1, 4, 8, or 14 bytes.

The 16550 also incorporates a transmit FIFO, though this feature is less critical as delays in interrupt service would only result in sub-optimal transmission speeds and not actual data loss.

The 16550A(F) version was a must-have to use modems with a data transmit rate of 9600 baud. Dropouts occurred with 14.4 kbit/s (V.32bis and higher) units and as compression was added with V.42 getting more data per interrupt was critical as data speed continued to increase.

Issue with the buffer
The original 16550 had a bug that prevented this FIFO from being used. National Semiconductor later released the 16550A which corrected this issue. Not all manufacturers adopted this nomenclature, however, continuing to refer to the fixed chip as a 16550.

According to another source, the FIFO issue was corrected only in the 16550AF model, with the A model still being buggy. (The C and CF models are okay too, according to this source.) The 16550AFN model added DMA transfers.

title: 16550 UART


text:
1643

January–March

 * January 21 – Abel Tasman sights the island of Tonga.
 * February 6
 * (17 Dhu al-Qadah 1052 AH) In India, the first ceremony at the nearly-complete Taj Mahal in Agra, the Mughal Emperor Shah Jahan observes the 12th anniversary of the death of his wife, Mumtaz Mahal, and opens the structure to thousands of mourners.
 * Abel Tasman sights the Fiji Islands.
 * March 13 – First English Civil War: First Battle of Middlewich – Roundheads (Parliamentarians) rout the Cavaliers (Royalist supporters of King Charles I) at Middlewich in Cheshire.
 * March 18 – Irish Confederate Wars: Battle of New Ross – English troops defeat those of Confederate Ireland.

April–June

 * April 1 – Åmål, Sweden, is granted its city charter.
 * April 28 – Francisco de Lucena, former Portuguese Secretary of State, is beheaded after being convicted of treason.
 * May 14 – Louis XIV succeeds his father Louis XIII as King of France at age 4. His rule will last until his death at age 77 in 1715, a total of 72 years, which will be the longest reign of any European monarch in recorded history.
 * May 19
 * Thirty Years' War: Battle of Rocroi: The French defeat the Spanish at Rocroi in France.
 * The New England Confederation is formed as a military alliance between Massachusetts Bay Colony, Plymouth Colony, Saybrook Colony (Connecticut), and New Haven Colony.
 * May 20 – Dutch expedition to Valdivia: The Dutch fleet (led by Hendrik Brouwer) is spotted off Carelmapu in Chile, soon afterwards landing nearby and plundering the fort and village.
 * June 30 – First English Civil War: Battle of Adwalton Moor – Royalists gain control of Yorkshire.

July–September

 * July 1 – The Westminster Assembly of theologians ("divines") and parliamentarians is convened at Westminster Abbey with the aim of restructuring the Church of England.
 * July 5 – First English Civil War: Battle of Lansdowne – Royalists gain a pyrrhic victory over the Parliamentarians near Bath, Somerset.
 * July 13 – First English Civil War: Battle of Roundway Down – Henry Wilmot, newly created Baron Wilmot, commanding Royalist cavalry, wins a crushing victory over Parliamentarian Sir William Waller.
 * August 24 – Dutch expedition to Valdivia: A Dutch fleet establishes a new colony in the ruins of Valdivia in southern Chile.
 * September 20 – First English Civil War: First Battle of Newbury – A strategic Parliamentarian victory is made over Royalist forces who are led personally by King Charles.

October–December

 * October 8 – The Shunzhi Emperor of China is crowned at five years old, 17 days after the death of his father and the decision of the Deliberative Council of Princes and Ministers.
 * October 28 – Dutch expedition to Valdivia: The Dutch end their occupation of Valdivia in Chile.
 * November 14 – Empress Meishō abdicates and Emperor Go-Kōmyō accedes to the throne of Japan.
 * November 24 – Thirty Years' War: Battle of Tuttlingen – France is defeated by forces of the Holy Roman Empire.
 * December 12 – Swedish Field Marshal Lennart Torstensson's forces enter Danish territory in Holstein, beginning the Torstenson War.
 * December 13 – First English Civil War: At the Battle of Alton in Hampshire, the Parliamentarians defeat the Royalists.
 * December 25 – Christmas Island in the Indian Ocean is sighted and named by Captain William Mynors of the British East India Company ship Royal Mary.
 * December 28 – Dutch expedition to Valdivia: The failed Dutch expedition arrives back at Recife in Dutch Brazil.

Date unknown

 * Baden-Baden is pillaged by the French.
 * An Calbhach mac Aedh Ó Conchobhair Donn, The Ó Conchubhair Donn, Chief of the Name of the Clan Ó Conchubhair, is popularly inaugurated as the last King of Connacht in Ireland.
 * Evangelista Torricelli invents the mercury barometer.
 * Paul de Chomedey, Sieur de Maisonneuve, places the first Mount Royal Cross atop Mount Royal above Montreal.
 * Jean Bolland publishes the first two volumes of the Acta Sanctorum (in Antwerp). This is the beginning of the Bollandists' work.
 * Miyamoto Musashi begins to dictate The Book of Five Rings (Go Rin No Sho) to his student; he will complete it in 1654, just before his death.
 * Roger Williams, co-founder of Rhode Island, publishes A Key into the Language of America.
 * The first professional book publisher to use printing press in Norway is established in Oslo.

January–March

 * January 2 – Eleonora d'Este, Italian princess, later nun (d. 1722)
 * January 4 – Sir Isaac Newton, English scientist (d. 1727)
 * January 7 – Sir Samuel Grimston, 3rd Baronet, English politician (d. 1700)
 * January 9 – Eleonoro Pacello, Italian Catholic prelate, Bishop of Pula (1689–1695) (d. 1695)
 * January 13 – Axel Wachtmeister, Count of Mälsåker, Swedish field marshal (d. 1699)
 * January 25 – John Hayes, English politician (d. 1705)
 * January 24 – Charles Sackville, 6th Earl of Dorset, English poet and courtier (d. 1706)
 * January 30 – Sir Francis Blundell, 3rd Baronet, Irish politician (d. 1707)
 * February 6
 * Charles Fanshawe, 4th Viscount Fanshawe, English politician (d. 1710)
 * Johann Kasimir Kolbe von Wartenberg, Prussian politician (d. 1712)
 * February 15 – García Felipe de Legazpi y Velasco Altamirano y Albornoz, Spanish Catholic prelate, Bishop of Tlaxcala (d. 1706)
 * February 25
 * Sultan Ahmed II of the Ottoman Empire (d. 1695)
 * Christian Franz Paullini, German physician (d. 1712)
 * March 4 – Fran Krsto Frankopan, Croatian baroque poet, nobleman and politician (d. 1671)
 * March 6 – Pierre de Langle, French bishop and theologian (d. 1724)
 * March 8 – Nabeshima Naoyuki, Japanese daimyō (d. 1725)
 * March 17 – Fabrizio Spada, Italian Catholic cardinal (d. 1717)
 * March 23 – Mary of Jesus de León y Delgado, Spanish Dominican lay sister and mystic (d. 1731)
 * March 25 – Louis Moréri, French priest and encyclopaedist (d. 1680)
 * March 28 – Anthony Dopping, Anglican Bishop of Meath (d. 1697)
 * March 29 – Louis Phélypeaux, comte de Pontchartrain (d. 1727)

April–June

 * April 3 – Charles V, Duke of Lorraine (d. 1690)
 * April 6 – Nehemiah Jewett, American colonial politician (d. 1720)
 * April 30 – Johann Oswald Harms, German Baroque painter (d. 1708)
 * May 3 – Georg Franck von Franckenau, German botanist (d. 1704)
 * May 7 – Stephanus Van Cortlandt, first native-born mayor of New York City (d. 1700)
 * May 8 – George Louis I, Count of Erbach-Erbach (1672–1693) (d. 1693)
 * May 9 – Charles Kirkhoven, 1st Earl of Bellomont, Dutch-born Irish peer (d. 1683)
 * May 10 – Gabriel Revel, French painter (d. 1712)
 * May 29 – Patrick Lyon, 3rd Earl of Strathmore and Kinghorne, Scottish peer and the son of John Lyon (d. 1695)

July–September

 * July 3 – Johann Ernst von Thun, Tyrolean Catholic bishop (d. 1709)
 * July 26 – Burchard de Volder, Dutch mathematician (d. 1709)
 * July 28 – Antonio Tarsia, Italian composer (d. 1722)
 * July 29 – Henri Jules, Prince of Condé (d. 1709)
 * August 3 – Charles de la Rue, French Jesuit, Latin poet (d. 1725)
 * August 16 – Mumtaz Shikoh, Mughal Empire emperor (d. 1647)
 * August 18 – William Louis, Prince of Anhalt-Harzgerode (1670–1709) (d. 1709)
 * August 21 – King Afonso VI of Portugal, King of Portugal and the Algarves (d. 1683)
 * August 26 – Cardinal de Bouillon, French Catholic cardinal (d. 1715)
 * September 3 – Lorenzo Bellini, Italian physician, anatomist (d. 1704)
 * September 5 – Sir William Portman, 6th Baronet, English politician (d. 1690)
 * September 6 – François-Joseph de Beaupoil de Sainte-Aulaire, French poet (d. 1742)
 * September 14
 * Jeremiah Dummer, American silversmith (d. 1718)
 * Joseph de Jouvancy, French historian (d. 1719)
 * September 17 – Francis Howard, 5th Baron Howard of Effingham, English peer (d. 1694)
 * September 18 – Gilbert Burnet, Scottish philosopher and historian (d. 1715)
 * September 27 – Solomon Stoddard, pastor of the Congregationalist Church in Northampton, Massachusetts (d. 1729)
 * September 30 – Samuel Hoadly, American-born English schoolmaster, writer of educational books (d. 1705)

October–December

 * October 5 – Zinat-un-Nissa, princess of the Mughal Empire (d. 1721)
 * October 14 – Bahadur Shah I, Mughal Emperor of India (d. 1712)
 * October 25 – Georg Ludwig Agricola, German composer (d. 1676)
 * November 1 – John Strype, English historian and biographer (d. 1737)
 * November 4 – Asano Nagatomo, Japanese daimyō who ruled the Akō Domain (d. 1675)
 * November 16 – Jean Chardin, French jeweller, traveller (d. 1713)
 * November 22 – René-Robert Cavelier, Sieur de La Salle, French explorer (d. 1687)
 * November 23 – Eberhard von Danckelmann, Prussian politician (d. 1722)
 * December 24 – Israel Kolmodin, Swedish hymnwriter and priest (d. 1709)
 * December 28 – Salomon van Til, theologian of the Dutch Reformed Church (d. 1713)

Date unknown

 * Ilona Zrínyi, Hungarian heroine (d. 1703)
 * Marie Grubbe, Danish countess (d. 1718)
 * Eva Krotoa, Khoi translator and interpreter (d. 1674)

Deaths

 * January 14 – John Bois, English scholar (b. 1560)
 * January 20 – Henry Danvers, 1st Earl of Danby, English noble (b. 1573)
 * February 11 – Countess Palatine Anna Maria of Neuburg, Duchess of Saxe-Altenburg (b. 1575)
 * February 15 – Countess Juliane of Nassau-Siegen, Landgravine of Hesse-kassel (b. 1587)
 * February 25 – Marco da Gagliano, Italian composer (b. 1582)
 * March 1
 * Girolamo Frescobaldi, Italian composer (b. 1583)
 * Rustam Khan, Georgian-Iranian soldier (b. c. 1588)
 * April 4 – Simon Episcopius, Dutch theologian (b. 1583)
 * April 12
 * Louis I, Count of Erbach-Erbach (1606–1643) (b. 1579)
 * Nicolaus Hunnius, German theologian (b. 1585)
 * April 13 – Margherita Farnese, Benedictine nun (b. 1567)
 * April 20 – Christoph Demantius, German composer (b. 1567)
 * April 28
 * Francisco de Lucena, Portuguese Secretary of State (b. c. 1578)
 * Philip III, Landgrave of Hesse-Butzbach (b. 1581)
 * May 14 – King Louis XIII of France (b. 1601)
 * July 12 – François Duquesnoy, Flemish Baroque sculptor in Rome (b. 1597)
 * July 25 – Robert Pierrepont, 1st Earl of Kingston-upon-Hull, English statesman (b. 1584)
 * August – Anne Hutchinson, English Puritan preacher (b. 1591)
 * August 7 – Margaret of Brunswick-Lüneburg, German noble (b. 1573)
 * August 22
 * Philippe de Carteret II, son of Philippe de Carteret I (1552– (b. 1584)
 * Johann Georg Wirsung, German anatomist (b. 1589)
 * September 15 – Richard Boyle, 1st Earl of Cork, Irish politician (b. 1566)
 * September 20, at the Battle of Newbury:
 * Lucius Cary, 2nd Viscount Falkland, English politician and writer (b. c. 1610)
 * Robert Dormer, 1st Earl of Carnarvon (b. c. 1610)
 * Henry Spencer, 1st Earl of Sunderland (b. 1620)
 * September 21 – Emperor Hong Taiji of China (b. 1592)
 * October 2 – Jean Chalette, French painter (b. 1581)
 * October 29 – Brilliana, Lady Harley, English noble, letter writer and war heroine (b. 1598)
 * November 3
 * John Bainbridge, English astronomer (b. 1583)
 * Paul Guldin, Swiss astronomer and mathematician (b. 1577)
 * Sun Chuanting, Ming dynasty general (b. 1593)
 * November 14
 * Henry Hastings, 5th Earl of Huntingdon, English noble (b. 1586)
 * George Aribert of Anhalt-Dessau, German nobleman (b. 1606)
 * November 15 – Tachibana Muneshige, Japanese samurai and soldier (b. 1567)
 * November 17 – Jean-Baptiste Budes, Comte de Guébriant, Marshal of France (b. 1602)
 * November 29
 * William Cartwright, English dramatist (b. 1611)
 * Claudio Monteverdi, Italian composer (b. 1567)
 * December 8 – John Pym, English statesman (b. 1583)
 * December 10 – Herman Wrangel, Swedish soldier and politician (b. 1584/1587)
 * December 11
 * Arthur Bell, English Franciscan martyr (b. 1590)
 * Henry Clifford, 5th Earl of Cumberland, English politician (b. 1591)
 * December 30 – Giovanni Baglione, Italian painter and historian of art (b. 1566)
 * approx. date – Henry Glapthorne, English dramatist (b. 1610)
 * date unknown
 * Sophia Brahe, Danish astronomer and horticulturalist (b. 1556)
 * María Pita, Spanish heroine (b. 1565)

title: 1643


text:
FTZ 1 TR 6

FTZ 1 TR 6 (or 1 TR 6) is the standard for the obsolete German national digital signalling protocol (D channel protocol) used for the ISDN. It has been superseded by DSS1 but is still in use on some lines and private exchanges.

1 TR 6 did not support multiple subscriber numbers but featured an Endgeräteauswahlziffer (EAZ, German "user device selection digit"). ISDN subscribers would get a sequence of 10 subsequent subscriber numbers, the last digit of which being the EAZ. The EAZ "0" was used for "global calls" to all connected devices.

1 TR 6 also offered semipermanent connections, which were (comparatively cheap) leased lines that could be temporarily disabled to use the B channel for other purposes.

It is said that the "TR" simply stands for "technische Richtlinie" (technical guidelines).

title: FTZ 1 TR 6