text:
Corum Jhaelen Irsei

Corum Jhaelen Irsei (known also as "the Prince in the Scarlet Robe" and "Corum of the Silver Hand") is a fictional fantasy hero in a series of novels written by Michael Moorcock. The character was introduced in the novel The Knight of Swords, published in 1971. This was followed by two other books published during the same year, The Queen of Swords and The King of Swords. The three novels are collectively known as the "Corum Chronicles trilogy" or "the Chronicles of Corum". Both The Knight of the Swords and The King of the Swords won the August Derleth Award in 1972 and 1973 respectively. The character then starred in three books making up the "Silver Hand trilogy", and has appeared in other stories taking place in Moorcock's multiverse.

Corum is a hero with disabilities, losing his left hand and right eye early in his first story. The hand and eye are later replaced by the Eye of Rhynn and the six-fingered Hand of Kwll, powerful artifacts that help Corum against his enemies. Corum is usually reluctant to use these two artifacts, as they involve methods and dark forces that conflict with his personal morality. Since the Eye of Rhynn causes Corum to see multiple planes of reality simultaneously, he often wears an eye patch over it to keep from being overwhelmed. After he loses both artifacts, Corum relies on a normal eyepatch and a silver prosthetic hand.

Corum is one of many incarnations of Michael Moorcock's "Eternal Champion", a soul who is reborn frequently throughout the multiverse and usually fights to restore or maintain the Cosmic Balance between Chaos and Law. In some stories, Corum's adventures allow him to meet other aspects of the Eternal Champion, such as Elric of Melniboné, Erekosë, and Dorian Hawkmoon. While Elric famously owes allegiance to the chaos god Arioch, Corum follows the cause of Law and begins his adventures by opposing the plans of Arioch (or his universe's version of the same being).

Fictional character biography
Corum lives during an age before recorded history, when human beings are rising on Earth and beginning to war with the planet's older societies. Corum's race, the Vadhagh, understands advanced science regarding the nature of reality. Through force of will, they are able to perceive and even shift through different dimensional planes for different purposes. The primitive humans of the age mistake these scientific tricks for sorcery and believe the Vadhagh engage in demonic rituals and witchcraft.

Corum's people are long-lived and believe they have nothing to fear from humans. Over the centuries, they become complacent and ignorant of the world around them. As a result, they are taken by surprise when a human tribe hunts them down and slaughters them. The last survivor as far as he knows, Corum is tortured and mutilated by the human barbarians, losing an eye and a hand before he escapes. He wants vengeance against all humanity, but later learns humans make up many societies of different beliefs and moralities. After encountering sorcerers and god-like beings, Corum learns all reality is influenced by the forces of Chaos and Law. Corum dedicates himself to maintaining balance between both forces, as disaster and death occur if either side holds too much influence.

The Swords Trilogy
This trilogy consists of The Knight of the Swords (1971), The Queen of the Swords (1971), and The King of the Swords (1971). In the United Kingdom it has been collected as an omnibus edition titled Corum, Swords of Corum and most recently Corum: The Prince in the Scarlet Robe (vol. 30 of Orion's Fantasy Masterworks series). In the United States the first trilogy has been published as Corum: The Coming of Chaos.

Plot
Prince Corum is a Vadhagh, one of a race of long-lived beings with limited magical abilities dedicated to peaceful pursuits such as art and poetry. Corum's father sends him away from their home, Castle Erorn, on a quest to learn the fate of their kinsmen. Corum eventually discovers that a group of "Mabden" (men), led by the savage Earl Glandyth-a-Krae, have raided all of the Vadhaugh's castles, and raped and slaughtered all of the Vadhaugh therein, including Corum's entire family. Arming himself, Corum attacks and kills several of the Mabden before being captured and tortured. After having his left hand cut off and right eye put out, Corum escapes by moving into another plane of existence, becoming invisible to the Mabden. They depart, and Corum is found by The Brown Man, a dweller of the forest of Laahr able to see Corum while out of phase. The Brown Man takes Corum to a being called The Giant of Laahr, who treats his wounds and explains he has a higher purpose.

Travelling to Moidel's Castle (a likely incarnation of Mont-Saint-Michel), Corum encounters his future lover, the Margravine Rhalina, a Mabden woman of the civilized land of Lwym an Esh. Having found out Corum's location by torturing and killing the Brown Man of Laahr, Glandyth-a-Krae marshalled his allies to Moidel's Castle. Glandyth had kept Corum's former hand and eye as souvenirs, and showed them to Corum to provoke a reaction. Rhalina uses sorcery (a ship summoned from the depths of the ocean and manned by her drowned dead husband and crew) to ward off an attack by Glandyth-a-Krae. Determined to restore himself, Corum and Rhalina travel to the island of Shool, a near immortal and mad sorcerer. During the journey Corum observes the Wading God, a mysterious giant who trawls the ocean with a net. Upon arriving at the island, Shool takes Rhalina hostage, and then provides Corum with two artifacts to replace his lost hand and eye: the Hand of Kwll and the Eye of Rhynn. The Eye of Rhynn allows Corum to see into an undead netherworld where the last beings killed by Corum exist until summoned by the Hand of Kwll.

Shool then explains that Corum's ill fortune has been caused by the Chaos God Arioch, the Knight of the Swords. When Arioch and his fellow Chaos Lords conquered the Fifteen Planes, the balance between the forces of Law and Chaos tipped in favor of Chaos, and their minions - such as Glandyth-a-Krae - embarked on a bloody rampage. Shool sends Corum to Arioch's fortress to steal the Heart of Arioch, which the sorcerer intends to use to attain greater power. Corum confronts Arioch, and learns Shool is nothing more than a pawn of the Chaos God. Arioch then ignores Corum, who discovers the location of the Heart. Corum is then attacked by Arioch, but the Hand of Kwll crushes the Heart and banishes the Chaos God forever. Before fading from existence, Arioch warns Corum that he has now earned the enmity of the Sword Rulers. Corum then meets with The Giant of Laahr, who reveals himself to be Lord Arkyn, the godlike Lord of Law whose realm had been taken over by Arioch. Arkyn tells Corum the destruction of Arioch is the first step towards Law regaining control of the Fifteen Planes. Corum returns to the island to rescue Rhalina, and discovers Shool has become a powerless moron. Shool is devoured by his own creations soon afterwards.

On another five planes, the forces of Chaos - led by Xiombarg, Queen of the Swords - reign supreme and are on the verge on eradicating the last resistance from the forces of Law. The avatars of the Bear and Dog gods plot with Earl Glandyth-a-Krae to murder Corum and return Arioch to the Fifteen Planes. Guided by Arkyn, Corum, Rhalina and companion Jhary-a-Conel cross the planes and encounter the King Without A Country, the last of his people who in turn is seeking the City in the Pyramid. The group locate the City, which is in fact a floating arsenal powered by advanced technology and inhabited by a people originally from Corum's world and his distant kin.

Besieged by the forces of Chaos, the City requires certain rare minerals to continue to power their weapons. Corum and Jhary attempt to locate the minerals and also encounter Xiombarg, who learns of Corum's identity. Corum slows Xiombarg's forces by defeating their leader, Prince Gaynor the Damned. Xiombarg is goaded into attacking the City directly in revenge for Arioch's banishment. Arkyn provides the minerals and confronts Xiombarg, who has manifested in a vulnerable state. As Arkyn banishes Xiombarg, Corum and his allies devastate the forces of Chaos. Glandyth-a-Krae, however, escapes and seeks revenge.

A spell - determined to have been cast by the forces of Chaos - forces the inhabitants of Corum's plane to war with each other (including the City in the Pyramid). Desperate to stop the slaughter, Corum, Rhalina and Jhary-a-Conel travel to the last five planes, ruled by Mabelode, the King of the Swords. Rhalina is taken hostage by the forces of Chaos and Corum has several encounters with the forces of Chaos, including Earl Glandyth-a-Krae.

Corum also meets two other aspects of the Eternal Champion: Elric and Erekosë, with all three seeking the mystical city of Tanelorn for their own purposes. After a brief adventure in the "Vanishing Tower", the other heroes depart and Corum and Jhary arrive at their version of Tanelorn. Corum discovers one of the "Lost Gods", the being Kwll, who is imprisoned and cannot be freed until whole. Corum offers Kwll his hand, on the condition that he aid them against Mabelode. Kwll accepts the terms, but reneges on the bargain until persuaded to assist. Corum is also stripped of his artificial eye, which belongs to Kwll's brother, the Lost God Rhynn. Kwll transports Corum and Jhary to the court of Mabelode, with the pair fleeing with Rhalina when Kwll directly challenges the Chaos God. On Kwll's instruction, Corum tosses the eye into the sea. It is recovered by the mysterious Wading God Corum had previously encountered, who is revealed to be Rhynn, which distracts Glandyth-a-Krae during his duel with Corum.

In a final battle, Corum avenges his family by killing Glandyth-a-Krae and decimating the last of Chaos' mortal forces. Kwll later appears to Corum and reveals that all the gods - of both Chaos and Law - have been slain in order to free humanity and allow it to shape its own destiny.

The Silver Hand Trilogy
This trilogy consists of The Bull and the Spear (1973), The Oak and the Ram (1973), and The Sword and the Stallion (1974). It was titled The Prince with the Silver Hand in the United Kingdom and The Chronicles of Corum in the United States respectively. The previous trilogy hinted at a Celtic or proto-Celtic setting for the stories - the terms mabden (human beings) and shefanhow (demons) occurring in these books are both Cornish language words. The Silver Hand trilogy is more explicit in its Celtic connections, with overt borrowings from Celtic mythology.

Plot
Set eighty years after the defeat of the Sword Rulers, Corum has become despondent and alone since the death of his Mabden bride Rhalina. Plagued by voices at night, Corum believes he has gone insane until old friend Jhary-a-Conel advises Corum it is in fact a summons from another world. Listening to the voices allows Corum to pass to the other world, which is in fact the distant future. The descendants of Rhalina's folk, the Tuha-na-Cremm Croich (see: Crom Cruach), who call Corum "Corum Llew Ereint" (see: Lludd Llaw Eraint), face extinction by the Fhoi Myore (Fomorians). The Fhoi Myore, seven powerful but diseased and barely sentient giants, with the aid of their allies have conquered the land and plunged it into eternal winter. Allying himself with King Mannach, ruler of the Tuha-na-Cremm Croich, Corum falls in love with his daughter Medhbh (see: Medb).

Corum also hears the prophecy of a seeress, who claims Corum should fear a brother (who will apparently slay him), a harp and above all, beauty. Corum seeks the lost artifacts of the Tuha-na-Cremm Croich - a sacred Bull, a spear, an oak, a ram, a sword and a stallion - which will restore the land. Corum gains new allies, Goffanon (a blacksmith and diminutive giant, a member of the Sidhe race) and Goffanon's cousin and true giant Illbrec. They battle the Fhoi Myore, who themselves have allies: a returned Prince Gaynor, the wizard Calatin and his clone of Corum, the Brothers of the Pine, the undead Ghoolegh and a host of giant demonic dogs. After being instrumental in the death of two of the Fhoi Myore and restoring to his senses the encircled Amergin, the High King and Chief Druid of the Tuha-na-Cremm Croich, Corum and his allies fight a final battle in which all their foes are destroyed.

Corum decides not to return his own world, and is attacked by his clone, whom he defeats with the aid of a spell placed on his silver hand by Medhbh. Medhbh, however, attacks and wounds Corum, having been told by the being the Dagdah that their world must be free of all gods and demi-gods if they are to flourish as a people. Corum is then killed with his own sword by his animated silver hand, thereby fulfilling the prophecy.

Awards
The August Derleth Award won by:
 * The Knight of the Swords - won in 1972
 * The King of the Swords - won in 1973
 * The Sword and the Stallion - won in 1975

Comics
First Comics published The Chronicles of Corum, a twelve issue limited series (Jan. 1986 - Dec. 1988) that adapted the "Swords Trilogy", and was followed by the four issue limited series Corum: The Bull and the Spear (Jan. - July (bi-monthly) 1989), which adapted the first book in the second trilogy.

These have been reprinted in 4 hardcover volumes by Titan Comics.

Role-playing game
Darcsyde Productions produced a supplement for use with Chaosium's Stormbringer (2001) role-playing game adapting the characters and settings from the Corum series for role-playing.

eBooks
Gollancz released the entire Corum stories in both print and ebook form, commencing in 2013. The ebooks are available via Gollancz's SF Gateway site.

Audiobooks
In 2016, GraphicAudio produced dramatized audiobook versions of Corum.

title: Corum Jhaelen Irsei


text:
Cumberland (disambiguation)

Cumberland is one of the historic counties of England.

Cumberland may also refer to:

Australia

 * Cumberland, Queensland, a ghost town west of Georgetown
 * Cumberland County, New South Wales, containing most of the Sydney metropolitan area
 * Cumberland Council, New South Wales
 * Cumberland Islands (Queensland)
 * Cumberland Park, South Australia, a suburb south of Adelaide
 * Cumberland Land District, Tasmania
 * Cumberland Plain, a biogeographical region in Sydney
 * Cumberland Plain Woodland, a woodland community in Sydney

Canada

 * Cumberland (Edmonton), Alberta, a neighbourhood
 * Cumberland (federal electoral district), former district in Nova Scotia
 * Cumberland (Nova Scotia provincial electoral district), former district
 * Cumberland (Saskatchewan provincial electoral district), current district
 * Cumberland (territorial electoral district), former district in what is now Saskatchewan
 * Cumberland, British Columbia
 * Cumberland, Ontario (disambiguation), three locations within the Canadian province of Ontario
 * Cumberland County, Nova Scotia
 * Cumberland House, Saskatchewan
 * Cumberland House Provincial Park, Saskatchewan
 * Cumberland Lake, Saskatchewan
 * Cumberland Sound, an inlet into Baffin Island

Place names by state

 * Cumberland County (disambiguation), in 10 of the United States, as well as in Canada and Australia
 * Cumberland, Georgia, an edge city of Atlanta, business district, and neighborhood
 * Cumberland Island, in Eastern Georgia, a geographical feature and a town
 * Cumberland Island National Seashore
 * Cumberland, Indiana
 * Cumberland, Iowa
 * Cumberland, Kentucky
 * Cumberland, Maine in Cumberland County
 * Cumberland Center, Maine
 * Cumberland, Maryland
 * Cumberland Narrows
 * Cumberland Bone Cave, a fossil-filled cave, Wills Mountain, Allegany County, Maryland
 * Cumberland, New Jersey
 * Cumberland Head, New York
 * Cumberland, Ohio
 * Cumberland, Oklahoma
 * Cumberland Township, Adams County, Pennsylvania
 * Cumberland Township, Greene County, Pennsylvania
 * Cumberland, Rhode Island, a town
 * Cumberland Hill, Rhode Island, within the town
 * Cumberland Gap, Tennessee, a town within Cumberland Gap National Historical Park
 * Cumberland Gap National Historical Park (see also below)
 * Cumberland City, Tennessee, in Stewart County on the Cumberland River
 * Cumberland, Virginia in Cumberland County
 * Cumberland, New Kent County, Virginia
 * Cumberland (New Kent, Virginia), a historic farm property
 * Cumberland, Washington
 * Cumberland, Wisconsin, a city
 * Cumberland, Barron County, Wisconsin, a town

Regional features

 * Cumberland Gap, a pass through the Appalachian Mountains near junction of Kentucky, Virginia, and Tennessee.
 * Cumberland Mountains in Tennessee and Kentucky
 * Cumberland Plateau in Tennessee and Kentucky
 * Cumberland River in Tennessee and Kentucky
 * Cumberland Falls
 * Lake Cumberland, an artificial lake on the Cumberland River
 * Cumberland Road, a historical road, part of the National Road, the first US federal highway
 * Cumberland Valley, in Pennsylvania and Maryland
 * Cumberland Valley AVA, wine region

Other places

 * Cumberland (unitary authority), Cumbria, England, covering a similar area to the historic county
 * Cumberland, Saint Vincent and the Grenadines
 * Cumberland (ward), one of the ancient divisions of the county of Cumberland, England
 * Cumberland River (disambiguation)

People

 * Cumberland (surname)
 * Duke of Cumberland, a former and currently suspended peerage of England, Great Britain and the United Kingdom
 * Earl of Cumberland, a former peerage of England

Companies

 * Cumberland Drugs, a defunct chain of pharmacies located in Quebec and eastern Ontario
 * Cumberland Farms, a chain of convenience stores found primarily in the northeastern United States
 * Cumberland Records, a record label

Education

 * Cumberland School of Law, in Birmingham, Alabama
 * Cumberland University, in Lebanon, Tennessee
 * University of the Cumberlands in Williamsburg, Kentucky

Food

 * Cumberland sauce, a fruit-based sauce
 * Cumberland sausage, a traditional sausage recipe in Britain

Healthcare institutions

 * Cumberland Infirmary, a hospital in Carlisle
 * West Cumberland Hospital, a hospital in Whitehaven

Ships

 * Cumberland (ship), four merchant ships
 * HMS Cumberland, eleven ships of the Royal Navy
 * USS Cumberland, three ships of the United States Navy

Sports

 * Cumberland (rugby league team), a team in the inaugural New South Wales Rugby League competition
 * Cumberland United, an Association Football club in Adelaide, Australia

Other uses

 * 1964 Cumberland B-52 crash, an accident involving a nuclear bomber
 * Army of the Cumberland, part of the Union Army in the American Civil War
 * Cumberland Arms, a pub in Adelaide, South Australia
 * Cumberland Building Society, a building society
 * Cumberland Presbyterian Church, a Presbyterian denomination in Protestant Christianity
 * Cumberland station (disambiguation), stations of the name

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

title: Cumberland (disambiguation)


text:
Capella (disambiguation)

Capella is a bright star in the constellation of Auriga.

Capella may also refer to:

Places

 * Capella, Queensland, a town in the Central Highlands Region, Australia
 * Capella, Aragon, a municipality in Huesca, Spain
 * Capella Island, a minor island of the U.S. Virgin Islands

Other uses

 * Capella (crater), an impact crater on the Moon
 * Capella (engineering), an open-source engineering solution
 * Capella (music), a musical ensemble
 * Capella (notation program), a program by capella Software AG
 * Mazda Capella, a model of automobile
 * USS Capella, a cargo ship of the United States Navy
 * Capella (concrete ship), a concrete ship built in World War II.
 * Capella Aircraft, an American aircraft manufacturer
 * Capella University, an online academic institution based in Minneapolis, Minnesota
 * Gallinago or Capella, a genus of snipes
 * Capella Resort, Singapore, a hotel in Singapore
 * Capella Space, an American space company

People with the name

 * Martianus Capella, writer and astronomer of late antiquity

title: Capella (disambiguation)


text:
Talk:Crux

Pointers
What about\the yytytgh"? (i.e. the two stars that point towards Crux that you use to estimate which direction is south) -- SJK
 * The pointers are Alpha and Beta Centauri, and thus a part of the constellation of Centaurus. --  B.d.mills  (T, C) 28 June 2005 12:23 (UTC)

This article needs a diagram that show how the pointers are used with crux to find the pole. Roger (talk) 08:21, 22 October 2008 (UTC)

 * There's a very good diagram already in Wikimedia Commons, in use at the Celestial Pole page: http://en.wikipedia.org/wiki/Celestial_pole . If there are no objections, I will place this diagram here, as well. I agree that a diagram is needed, as the text description doesn't make it clear where to find the Pointer Stars. rowley (talk) 17:35, 10 January 2012 (UTC)

flags
There are several countries which have the Southern Cross on their flags, such as New Zealand and Australia. Prehaps a reference to that could be made? --Gregstephens 08:12, 25 Feb 2005 (UTC)
 * I agree. Maybe I'll add something about that this weekend or so.  JYolkowski 23:34, 25 Feb 2005 (UTC)

Krux

Move to "Southern Cross"
I think we should move Southern Cross to Southern Cross (disambiguation) and move Crux to Southern Cross. If there are no objections in a week I will do it myself.

My rationale is that it is in keeping with English Wikipedia policy to use the common English name as the name of the article. Southern Cross is already a disambiguation page, so there is no need to change any content (except put a link to the disambiguation page at the top of the new Southern Cross page). Are there any objections?

Ben Arnold 01:55, 25 Jun 2005 (UTC)

 * Just one: all other constellations are in Latin, so it's not really in keeping with Wikipedia usage. kwami 06:57, 2005 Jun 25 (UTC)

I object as well. 08:56, 25 Jun 2005 (UTC)

I also object for the reasons stated above. --  B.d.mills  (T, C) 09:33, 26 Jun 2005 (UTC)

Well then how about making Southern Cross redirect here, and move the existing Southern Cross page to Southern Cross (disambiguation)? At least that way if we do decide later on to change Crux to Southern Cross we don't have to merge two pages. Ben Arnold 11:39, 26 Jun 2005 (UTC)

Because then this page would say "for other uses of Southern cross, see Southern cross (disambiguation)", but the page title would be "crux", so the phrase would be obscure. 12:22, 26 Jun 2005 (UTC)

This is done elsewhere in Wikipedia, the phrasing is usually along the lines of Southern Cross redirects here, for other uses of Southern Cross, see Southern Cross (disambiguation). There's probably a template for this. Ben Arnold 2 July 2005 02:14 (UTC)

I've found it:

Ben Arnold 2 July 2005 03:29 (UTC)

 * Since when is "Crux" the most common name for the constellation? I for one have never heard it called anything other than the Southern Cross. 75.76.213.106 (talk) 02:46, 30 June 2010 (UTC)

 * Yeah, I'm failing to see how this shouldn't fall under WP:COMMONNAME, The Southern Cross is what it's overwhelmingly referred to in English sources. There's no explicit convention cited here so that argument would fall under WP:OSE, and even then as per commonname it should only be applied if it produces clear benefits outweighing the use of common names, which there isn't here as far as I can see, and no one has presented any arguments for there being one. Number36 (talk) 08:28, 6 February 2015 (UTC)

 * "Southern Cross" can be interpreted as the name for the pattern of five stars whereas Crux is the name for the constellation which has more, fainter stars, borders etc. So we lose accuracy and exactness. Also, all 88 constellations are at their Latin names. Cas Liber (talk · contribs) 19:08, 6 February 2015 (UTC)
 * Actually I read this before I noticed that Ben Arnold's suggestion in the comments above to have 'Southern Cross' redirect here had been applied, that seems fine.Number36 (talk) 23:29, 6 February 2015 (UTC)

 * Why not call it "Crux (Southern Cross)"...or similar? No one outside of the very small sphere of astronomy acolytes calls it "Crux."  Common name should have better placement at a minimum. --2602:306:BC24:8C00:8826:9C9B:F7F4:4793 (talk) 13:21, 19 June 2016 (UTC)

Using Britain's sky?
"Although these stars were known to the ancient Greeks, gradual precession of the equinoxes had lowered them below the European skyline so that they were forgotten. For example at the latitude of Britain in 5000 BC the constellation still was completely visible at springtime midnight. [1]"

Since the article was talking about the ancient Greeks, wouldn't it be better if we use the latitude of Athens rather than the latitude of Britain to generate the sky chart? Also, 5000 B.C. seems a bit too early. Maybe we could use 1000 B.C., the start of the ancient Greek civilization? --Bowlhover 03:00, 13 December 2006 (UTC)

Wikiproject Brazil?
What's so special about Brazil vis-a-vis Crux that qualifies this linkage? Might as well then link it to all southern hemisphere countries. Roger 17:55, 15 August 2007 (UTC)

Agreed. The only difference between their Southern Cross is the 5th star placement, it's opposite the other versions. —Preceding unsigned comment added by 67.124.38.231 (talk) 23:25, 8 December 2007 (UTC)

Upload an image?
I got a good photo of crux last night, would it be ok if i uploaded it, it is of better quality than the current image of crux that is hosted. —Preceding unsigned comment added by Alphamone (talk • contribs) 02:40, 21 September 2007 (UTC)

Just do it.. the current one is TERRIBLE.. I have a few as well but I'd have to scan them in first. schroding79 (talk) 00:26, 9 January 2009 (UTC)

Ok, picture replaced, feel free to rewrite the caption if you wish, as I am not that good at writing descriptions. --Alphamone (talk) 11:17, 12 January 2009 (UTC)

Isn't it similar?
Isn't this cross too similar to the cross where Jesus was supposedly crucified? —Preceding unsigned comment added by 84.126.1.209 (talk) 22:45, 9 November 2007 (UTC)
 * No. --24.57.151.98 (talk) 20:19, 23 March 2008 (UTC)
 * The text in the "History" section associating the constellation with the crucifiction of Jesus is totally spurious. Unless someone can come up with a citation written by a contemporary commentator who made the association. None of the gospels or later biblical texts mention it at all. Roger (talk) 20:54, 24 March 2008 (UTC)

Visible only from southern hemisphere?
The introduction states that Crux is "today visible only from the southern hemisphere." Surely this is incorrect? At declination -60 it should be partially or wholly visible in the northern hemisphere in springtime at latitudes south of 30N. Perhaps this sentence is a leftover from some edit about visibility in Athens, referred to in the previous sentence?KiwiDave (talk) 10:04, 12 January 2009 (UTC)

Dnheff, you are completely correct. At the various Star Parties in Florida - indisputably a Northern Hemsiphere location - it is well visible, and has been imaged from there numerous times. Old_Wombat (talk) 09:29, 9 January 2012 (UTC) Lets get generalized on that some more to help other- Not Just the Florida Peninsula, BUT nearly all of Florida - Includes the Panhandle - and therefore also Southern coast line of Mississippi, Alabama, Louisiana, & Texas. At these latitudes will take more effort research and planning to see it. I expect at these latitudes Also must to be on the water- Gulf Mexico as horizon (otherwise blocked view by )a Although offshore I have sighted it myself from northern edges of Gulf of Mexico. Not only incorrect - but we should modify main page. Maybe event BP should add this fact into their Gulf Mexico Tourism advertising! Wfoj2 (talk) 21:14, 31 December 2012 (UTC)

"Upside down"
Perhaps it should be mentioned that the cross as it is popularly known, ie. with Alpha-Crucis at the "bottom" and Gamma-Crucis at the "top" (ie. as it appears on the Australia/New Zealand flags, etc) is in fact NOT the way it appears in the southern sky, where Acrux is actually at the top and Gacrux bottom, appearing more like an anchor (hence the Maori name) than a cross.

Perhaps the popular image of the "upright" cross comes a) from the point of view of European explorers who first saw it the "correct" way up as they came over the equator before eventually reaching the southern lands and seeing it from their perspective; and b) due to the fact that it might be considered sacriligious/un-christian if its true nature of an upside-down cross is popularized and used in the flags and popular culture in general? BigSteve (talk) 15:11, 17 February 2009 (UTC)

 * Fellows, this is not correct. The main axis (the "longer" axis) of the southern cross points approximately in the direction of the south pole. Therefore, between the Equator and the tropics, the southern cross appears either laying "horizontal" or in the "correct" upright form over the horizon (depending the time of the night and the time of the year). This is what the first Europeans saw. In fact, on latitudes just north of the Equator you can see it over the horizon only in the "normal" cross shape. Further south, for most of Australia, New Zealand, Argentina and Chile, the southern cross is nearly circumpolar. As you find it every night on the sky, it can appear to you on all possible orientations. (The same happens in the Northern hemisphere with the Big Dipper and Cassiopeia if you are in Canada, Scandinavia or Northern Russia.)  Seeing the Southern Cross "upside down" is the harder as you go north, because it would be below your horizon. Check this link for further comments: []   On the other hand, if you were at the south pole, every time you face the Southern Cross it will appear as an upside down cross (of course, only in the six-month winter night). Note that the apparent latitude of the Southern Cross is approximately 60-South, therefore it will be over your head near Tierra del Fuego at some time of the year or the day. That is, it will appear to you in all possible orientations you want by just turning on your spot!.Nordisk varg (talk) 16:56, 17 February 2009 (UTC)

 * Nice explanation - especially on the many different angles it can assume. i simply meant that perhaps the article should note that, as you also say, the vertical position of Crux with GaCrux at the top is very uncommon from places as far south as Southern Australia, NZ etc, and that perhaps the popular gamma-top vertical representation is largely religion-based, considering its rarity in southern skies? it is such an iconic constellation that it comes as a surprise to many people to see how differently it is positioned as seen from the places that use it as their symbol. BigSteve (talk) 17:43, 17 February 2009 (UTC)

 * I would leave it as it is. I don't think it represents much of a bias, religious or otherwise. As I said, the "upright" shape becomes uncommon only to the south of Tierra del Fuego (an area where basically nobody lives, as it is much more southern than New Zealand's south island). Whereas all configurations are visible south of the tropic of Capricorn, the mainly "upright-like" ones (say, a 60-degree rotation to the left and right of the upright) are the ones that you are more likely going to see any night north of 40-South, say, north of Sidney, Buenos Aires, or Cape Town. In northern Australia, the "upside-down" configuration is usually too close to the horizon for sharp visibility, and thus is, so-to-speak, "the least common configuration." The Flag of Santa Cruz (southern Patagonia, Argentina)[] makes this point very well as they display a 120-degree-rotation of the "upright" cross over the horizon (or 60-degree from the "upside-down" shape), which is a configuration that you can see that clearly (on most nights) only if you are quite south (in this case, about 50-south which is farther south of all of Australia!). So, unless we want to include all these long explanations in the main text, any other revision would be a bit misleading. Let's leave it as it is? Nordisk varg (talk) 20:59, 17 February 2009 (UTC)

 * ok! :-) BigSteve (talk) 16:12, 19 February 2009 (UTC)

I looked this article up because of my own questions regarding the actual polar orientation of crux. I can view crux from the island of Cebu in the Philippines. Predawn in November it is lying on it's side, and around 10pm in April it sets itself upright to the horizon. Therefore I would deduce that when the Southern Cross is "upright" then due south is slightly to the right or left of the constellation, at the horizon. It's easy to see how the "upright" cross would be an easy help to mariners, especially when you can look behind you at Ursa Major, and find Polaris, too. Where I am is about 10 degrees North Latitude. I'm looking for a skychart marking the actual point of the celestial south pole in relation to Crux, so I can know the answer. That would help. —Preceding unsigned comment added by 121.1.37.171 (talk) 21:34, 11 November 2009 (UTC)

 * Up to a good approximation, the South Pole lies on the line that continues the major axis of the Southern Cross, at a distance of ca. 3.5 axis lengths. In other words, regardless of how Crux appears (lying on the side or upright), the major axis of Crux indicates the direction pointing to the south pole (with a small correction to the left). Two better approximations are usually quoted: (i) One finds the south pole as the midpoint between the Acrux (the "bottom" of the upright cross) and Achernar, the brightest star on "the other side" of the pole with respect to Crux. This will not help you however in the Philippines, because you must be quite south to see all these stars simultaneously, at least 35 S latitude. (ii) Take a straight line at right angles on the middle of alpha-beta Centauri line (the "pointers"). Then find where that line crosses the continuation of the major axis of Crux. That's the south pole. This option may be more useful if you live near the equator, because you can see the pointers and the upright cross at the same time, though not quite the intersection of the lines I mentioned before. I hope this helps!Nordisk varg (talk) 18:06, 9 April 2010 (UTC)

 * This discussion is one demonstration of why I think this is the single-most overrated constellation in the sky. A cross?  Huh--it's just four corners of a quadrilateral, one of hundreds in the sky.  Without so much as a star marking the intersection of the two bars of the cross, it's hopeless.  The crux of the matter is that this article fails because it doesn't reference the fact that this constellation epitomizes the arbitrary nature of constellations, and it should be changed so that it does so. 76.106.149.108 (talk) 09:27, 2 September 2013 (UTC)

Possible Popular Culture Referance
The Southern Cross is referenced heavily in the NES game Star Tropics. Could this be mentioned in the main page under a Popular Culture heading? Legionaireb (talk) 17:23, 28 August 2009 (UTC)

The Australian Cricket team's victory song is not 'Beneath' The Southern Cross.

It has its own entry here.

http://en.wikipedia.org/wiki/Under_the_Southern_Cross_I_Stand 124.185.11.208 (talk) 10:20, 10 March 2010 (UTC)

Dante reference to Crux
Though the constellation was no longer visible from the Mediterranean in the Middle Ages, Dante makes an unmistakable allusion to it in the first canto of Purgatory. In Dante's cosmos, Mt Purgatory is situated in the south seas, approximately at the antipode of Jerusalem, and as Dante approaches the shore he sees four bright stars which, he specifies, have never been visible from Europe or roughly from the northern hemisphere. Dante had an above average knowledge of the stars, the Comedy has a large number of references to the sun, moon, planets and stars and their positions and these are orderly set out, so there isn't much doubt that he is really referring to the Southern Cross. The reference is widely discussed in the comment literature to the Comedy and also by Björn Landström, prominent historian of old ships and journeys of exploration and artist, in his The Road to India, see also [].

Both Landström and the web page suggest that Dante may have heard about the constellation from someone who had been near or south of the equator; probably a merchant or a missionary. We know at least one European missionary who had been to sub-equatorial Africa at the time and returned to Western Europe; you needed roughly to have been at least as far south as Abessinia or soutnern India. Marco Polo might also have seen it, at least on his return home from China by way of the Malacca Sound, though it's unknown whether Dante had ever read or met Polo (who was. of course, his contemporary) Strausszek (talk) 20:45, 12 May 2010 (UTC)

Portuguese discovery
Crux was not re-discovered by Amerigo Vespucci in an expedition to South America in 1501. Nor was it "unmistakably" described by Dante. The constellation and it nautical use was described by the Portuguese sailors while rounding Africa in the 15th century. There are documents about it, I'll later upload their description. —Preceding unsigned comment added by 96.250.167.253 (talk) 05:08, 18 November 2010 (UTC)

 * Sorry, your ref to a letter by that captain doesn't prove in any way that he was the first to note the constellation. I left your image in but deleted the claim that the Portuguese "discovered" it or that it was unknown prior to around that time. National pride doesn't count as a reason in an encyclopaedia, and Dante's reference is plain, and widely discussed in the literature about his poem.Strausszek (talk) 14:45, 27 June 2011 (UTC)

"... In other astronomical systems ... "
For completeness, the Australian Aboriginal section needs a bit of editing. I suggest the following:

There are several different interpretations of the Southern Cross by various Australian aboriginal groups. The most common one is that Crux and the Coalsack mark the head of the 'Emu in the Sky'. Others have Crux itself as a possum sitting in a tree and a representation of the sky deity Mirrabooka, and in still other Aboriginal cultures it is seen as a fish, commonly a shark or a stingray. The 'Emu in the Sky' is significantly different from almost all other interpretations of constellations in that it is a true outline figure, in sillhouette (that is, a black Emu against a bright background); whereas virtually all other constellations are simple stick figures made from joining stars with straight lines. Old_Wombat (talk) 09:39, 9 January 2012 (UTC)

External links modified
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'Cultural Significance' Section
In the Section "Cultural significance", there are many problems with how this text is presented. Significantly, there is no / no acceptable citations within this text, and much of it fails necessary WP:NPOV, WP:Notability, WP:Balance. I have also removed the following text:

 * "The first poetic reference to the Southern Cross appears to be by Thomas Bracken of Dunedin (ref: Broughton, W.S (22 June 2007). "Bracken, Thomas 1843 – 1898". Dictionary of New Zealand Biography. Ministry for Culture and Heritage. Retrieved 9 November 2010.) in his poem "God Defend New Zealand" (Ref: Broughton., W. S. (30 October 2012). "Bracken, Thomas". Dictionary of New Zealand Biography. Te Ara - the Encyclopedia of New Zealand. Retrieved 26 Jan 2018. which was later adopted as the national anthem of New Zealand) (Ref: Max Cryer. "Hear Our Voices, We Entreat: The Extraordinary Story of New Zealand's National Anthems". Exisle Publishing. Archived from the original on 17 May 2015.) It was set to the music of John Joseph Woods of Lawrence, New Zealand and first performed in Dunedin on Christmas Day 1876. In it Bracken wrote of a triple star which corresponds to the predominant first-magnitude blue-white star of Alpha Crucis or Acrux. That triple star is the southern-most member of the constellation and poetically corresponds to New Zealand's own deep southern position in the Pacific Ocean. It is also suggested that it further plays on the fact that New Zealand herself was made up of three main islands (Ref: "National anthems: History of God Defend New Zealand". Ministry for Culture and Heritage. 23 March 2015. Retrieved 26 January 2018.). Bracken did not state his specific meaning and it is open to debate [Folksong.org.nz. ("E Ihowa atua: "Triple Star""].
 * Guard Pacific's triple star. From the shafts of strife and war, Make her praises heard afar, God defend New Zealand.'' (Ref:National hymn, God defend New Zealand. 1876; ID: GNZMS 6, Grey New Zealand manuscripts, Auckland Council)

 * This text is probably better placed under articles Flag of New Zealand God Defend New Zealand or National anthems of New Zealand (but nothing like this is mentioned in them.)
 * References are dubious or not relevant. Particularly stating: "In it Bracken wrote of a triple star which corresponds to the predominant first-magnitude blue-white star of Alpha Crucis or Acrux." then follow by saying "Bracken did not state his specific meaning and it is open to debate." defies WP:Verifiable. Neither of the sources really say this, and is clearly opinion. (The three island story is more likely, being North, South and Stewart Island, with saying "It is also suggested that it further plays on the fact that New Zealand herself was made up of three main islands" further weakening the argument.) None is really relevant to Crux, with too man degrees of freedom. Therefore, it was right to delete.
 * The Nation Anthem is trivial information. Mentioning the Southern Cross is in both Australian and New Zealand is all that is required here. e.g. "In the national anthems of Australia and New Zealand both mention the Southern Cross in their songs."
 * Cited material should be accessible to read and back-up the statements.
 * "The first poetic reference to the Southern Cross appears to be..." is merely opinion and is based on what actual evidence. It is clearly text designed for WP:Peacock
 * The references are badly formatted, and I have modified them here for readability in this Talkpage.

I have also removed this uncited / poorly written or structured / unsupported text here:

 * "In Australia, the Southern Cross played a crucial role as symbol of the Eureka Stockade. In the Eureka Oath from Peter Lalor's famous speech in 1854 under the Eureka Flag he proclaimed: "We swear by the Southern Cross to stand truly by each other and fight to defend our rights and liberties." Of the Australian national flag, the Australian poet Banjo Paterson wrote in 1893 (before Australia designed and adopted a national flag): The English flag may flutter and wave, where the world wide oceans toss, but the flag the Australian dies to save, is the flag of the Southern Cross.''"

 * "The Southern Cross was written into the lyrics of "Advance Australia Fair" in 1901: "Beneath our radiant Southern Cross"; Australia adopted this song as its national anthem in 1984. The victory song of the Australian national cricket team is entitled "Under the Southern Cross I Stand".

Other unjustified text is like; ''Beginning in the colonial age,", (ambiguous meaning) "...whose pioneers were colloquially referred to as sons and daughters of the Southern Cross." (The linked cite does not say this at all.)

Please first consider discussing all this deleted text before re-adding this back in the article. Thanks. Arianewiki1 (talk) 01:12, 28 January 2018 (UTC)

New Bold Attempt and Significant Update
I have just made an update. I've have fixed various broken or new links for the five main stars, and also re organised the images. I have corrected several syntax or context errors. New errors may have been accidental introduced and may need corrections.

I think that the Section on 'Cultural significance' needs revision checks for relevance. It is very difficult to read, and may be better perhaps divided in a new separate article? "Cultural significance of the Southern Cross'?

Also be aware that the pages of the five main stars need updating to make the changes made in this article, at least to make the text self-consistent with these articles. (I'll attempt these soon.) Arianewiki1 (talk) 01:56, 30 April 2019 (UTC)

Coalsack Nebula--southeast, not southwest?
The introductory section says: "To the southwest, find part of the extensive 7° by 5° dark nebula known as the Coalsack Nebula, ..." I think it should be southeast. But I'm not sure enough to make the change myself. Looking it all up in other places, I think that as the constellation is pictured in this article--with North up--the Coalsack Nebula should be to the lower left of the constellation. Now, here's a point that easily raises confusion. When you look at the sky in such a way that North, to you, is up, then to your left is East and to your right is West. This is the opposite of what one normally thinks. That's because if you're looking a map, you're essentially looking down onto the Earth. Looking at the sky, you've turned your head around, in effect. Uporządnicki (talk) 18:16, 1 May 2019 (UTC)

 * Uporządnicki Thanks for this. Your quite right. (I didn't think I edit or write this part, and just assumed it was true.) Usage in the sky when determining the cardinal points it is best to using position angle. PA is about 160°, which is southeast. (6.5° from the centre of Crux.) Hartung (1968) says it is 'Sf.' - south following, which is southeast. Some sources use Acrux, where the centre of the Coalsack lies 3° east (PA 91°) I've fixed this and I'll add Acrux statement too. Pleasure to engage with another editor to further improve this article. Arianewiki1 (talk) 23:33, 1 May 2019 (UTC)
 * Arianewiki1, you might or might not remember this exchange we had almost two years ago. For whatever interest it might hold for you, I've just discovered--and put right--the same confusion regarding the Jewelbox. Three times in two separate statements, it said the Jewelbox is to the West; of course, it's to the East.  I've scoured the article--searched "coal" and "jewel", searched "west" and "east" (the latter turned up every instance of "least")--and I think the glitch has been definitively annihilated. Uporządnicki (talk) 14:14, 2 February 2022 (UTC)
 * You're unlikely to get a reply from an indefinitely-banned editor, but thanks for catching these mistakes. There are probably more if you look hard enough, but I can't think of a good way to automate the search.  Lithopsian (talk) 17:10, 2 February 2022 (UTC)
 * On your first point--Oh, my! Who knew?  Well, obviously, you did.  OK.  About your second--Yeah, I don't know how one would even begin to automate that--short of a bot that can actually understand language.  You look at a star chart and you know North is up, as is the convention, look at something to the right, and you think "East."  It's an easy mistake--even if you know better.  But if we could automate everything in Wikipedia to be correct, half the fun would be gone. Uporządnicki (talk) 17:25, 2 February 2022 (UTC)

"Asterism" and Southern Cross
Following the pattern of Ursa Major article viz "The Great Bear", Southern Cross is the common English name for the constellation, not just the asterism of the 4 brightest stars. Previous wording of first paragraph was leading to a misconception in other articles that the Southern Cross "is an asterism" when of course in common usage the phrase's meaning is identical with the formal Crux (which of course literally means "Cross"). Defining Southern Cross to be an "asterism" makes no more sense than would be having the Ursa Major article describe the "Great Bear" as the asterism of the stars that look like a great big bear. 69.140.25.127 (talk) 18:09, 7 March 2020 (UTC)
 * Hmmm, kappa crucis and lambda crucis are not part of the asterism (so there are constellation stars outsdie the asterism). Point wirth discussing though Cas Liber (talk · contribs) 20:28, 7 March 2020 (UTC)
 * There are too few (where "too few" effectively means "none") references for verification of just what is meant by Southern Cross, for example whether it is a synonym for the constellation Crux, a name for an asterism of four or five stars, or both. Or possibly neither.  Without reliable references, it is somewhat arbitrary to describe it as one thing or the other.  There are several instances in the article where "Southern Cross" is explicitly described as an asterism consisting of four, possibly five, stars.  Since the lead just summarises the body of the article, and hence contains no references at all (not that the body really has any relevant references), I have reverted those edits to the lead.  Without any prejudice to the eventual outcome of any discussions or changes.  The article is now reasonably consistent in using the term "Southern Cross" to refer strictly to those four or five stars, or loosely to refer to the prominent grouping of stars in the constellation Crux, although as mentioned no real references to support this usage.  Lithopsian (talk) 20:26, 8 March 2020 (UTC)

Grammar
Search "There follow four less dominant stars ... " Not sure what the intended sentence was supposed to be, but it sounds odd. SquashEngineer (talk) 20:24, 20 January 2021 (UTC)
 * That sentence, with minor variations, is long-standing and I think intentional. However, I agree that it is utterly unintelligible to anyone who doesn't already know what the sentence is trying to express.  I'll have a go at it.  Lithopsian (talk) 20:33, 20 January 2021 (UTC)

title: Talk:Crux


text:
Complex instruction set computer

A complex instruction set computer (CISC ) is a computer architecture in which single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or are capable of multi-step operations or addressing modes within single instructions. The term was retroactively coined in contrast to reduced instruction set computer (RISC) and has therefore become something of an umbrella term for everything that is not RISC, where the typical differentiating characteristic is that most RISC designs use uniform instruction length for almost all instructions, and employ strictly separate load and store instructions.

Examples of CISC architectures include complex mainframe computers to simplistic microcontrollers where memory load and store operations are not separated from arithmetic instructions. Specific instruction set architectures that have been retroactively labeled CISC are System/360 through z/Architecture, the PDP-11 and VAX architectures, and many others. Well known microprocessors and microcontrollers that have also been labeled CISC in many academic publications include the Motorola 6800, 6809 and 68000 families; the Intel 8080, iAPX 432 and x86 family; the Zilog Z80, Z8 and Z8000 families; the National Semiconductor NS320xx family; the MOS Technology 6502 family; the Intel 8051 family; and others.

Some designs have been regarded as borderline cases by some writers. For instance, the Microchip Technology PIC has been labeled RISC in some circles and CISC in others.

Incitements and benefits
Before the RISC philosophy became prominent, many computer architects tried to bridge the so-called semantic gap, i.e., to design instruction sets that directly support high-level programming constructs such as procedure calls, loop control, and complex addressing modes, allowing data structure and array accesses to be combined into single instructions. Instructions are also typically highly encoded in order to further enhance the code density. The compact nature of such instruction sets results in smaller program sizes and fewer main memory accesses (which were often slow), which at the time (early 1960s and onwards) resulted in a tremendous saving on the cost of computer memory and disc storage, as well as faster execution. It also meant good programming productivity even in assembly language, as high level languages such as Fortran or Algol were not always available or appropriate. Indeed, microprocessors in this category are sometimes still programmed in assembly language for certain types of critical applications.

New instructions
In the 1970s, analysis of high-level languages indicated compilers produced some complex corresponding machine language. It was determined that new instructions could improve performance. Some instructions were added that were never intended to be used in assembly language but fit well with compiled high-level languages. Compilers were updated to take advantage of these instructions. The benefits of semantically rich instructions with compact encodings can be seen in modern processors as well, particularly in the high-performance segment where caches are a central component (as opposed to most embedded systems). This is because these fast, but complex and expensive, memories are inherently limited in size, making compact code beneficial. Of course, the fundamental reason they are needed is that main memories (i.e., dynamic RAM today) remain slow compared to a (high-performance) CPU core.

Design issues
While many designs achieved the aim of higher throughput at lower cost and also allowed high-level language constructs to be expressed by fewer instructions, it was observed that this was not always the case. For instance, low-end versions of complex architectures (i.e. using less hardware) could lead to situations where it was possible to improve performance by not using a complex instruction (such as a procedure call or enter instruction) but instead using a sequence of simpler instructions.

One reason for this was that architects (microcode writers) sometimes "over-designed" assembly language instructions, including features that could not be implemented efficiently on the basic hardware available. There could, for instance, be "side effects" (above conventional flags), such as the setting of a register or memory location that was perhaps seldom used; if this was done via ordinary (non duplicated) internal buses, or even the external bus, it would demand extra cycles every time, and thus be quite inefficient.

Even in balanced high-performance designs, highly encoded and (relatively) high-level instructions could be complicated to decode and execute efficiently within a limited transistor budget. Such architectures therefore required a great deal of work on the part of the processor designer in cases where a simpler, but (typically) slower, solution based on decode tables and/or microcode sequencing is not appropriate. At a time when transistors and other components were a limited resource, this also left fewer components and less opportunity for other types of performance optimizations.

The RISC idea
The circuitry that performs the actions defined by the microcode in many (but not all) CISC processors is, in itself, a processor which in many ways is reminiscent in structure to very early CPU designs. In the early 1970s, this gave rise to ideas to return to simpler processor designs in order to make it more feasible to cope without (then relatively large and expensive) ROM tables and/or PLA structures for sequencing and/or decoding.

An early (retroactively) RISC-labeled processor (IBM 801 – IBM's Watson Research Center, mid-1970s) was a tightly pipelined simple machine originally intended to be used as an internal microcode kernel, or engine, in CISC designs, but also became the processor that introduced the RISC idea to a somewhat larger audience. Simplicity and regularity also in the visible instruction set would make it easier to implement overlapping processor stages (pipelining) at the machine code level (i.e. the level seen by compilers). However, pipelining at that level was already used in some high-performance CISC "supercomputers" in order to reduce the instruction cycle time (despite the complications of implementing within the limited component count and wiring complexity feasible at the time). Internal microcode execution in CISC processors, on the other hand, could be more or less pipelined depending on the particular design, and therefore more or less akin to the basic structure of RISC processors.

The CDC 6600 supercomputer, first delivered in 1965, has also been retroactively described as RISC. It had a load–store architecture which allowed up to five loads and two stores to be in progress simultaneously under programmer control. It also had multiple function units which could operate at the same time.

Superscalar
In a more modern context, the complex variable-length encoding used by some of the typical CISC architectures makes it complicated, but still feasible, to build a superscalar implementation of a CISC programming model directly; the in-order superscalar original Pentium and the out-of-order superscalar Cyrix 6x86 are well-known examples of this. The frequent memory accesses for operands of a typical CISC machine may limit the instruction-level parallelism that can be extracted from the code, although this is strongly mediated by the fast cache structures used in modern designs, as well as by other measures. Due to inherently compact and semantically rich instructions, the average amount of work performed per machine code unit (i.e. per byte or bit) is higher for a CISC than a RISC processor, which may give it a significant advantage in a modern cache-based implementation.

Transistors for logic, PLAs, and microcode are no longer scarce resources; only large high-speed cache memories are limited by the maximum number of transistors today. Although complex, the transistor count of CISC decoders do not grow exponentially like the total number of transistors per processor (the majority typically used for caches). Together with better tools and enhanced technologies, this has led to new implementations of highly encoded and variable-length designs without load–store limitations (i.e. non-RISC). This governs re-implementations of older architectures such as the ubiquitous x86 (see below) as well as new designs for microcontrollers for embedded systems, and similar uses. The superscalar complexity in the case of modern x86 was solved by converting instructions into one or more micro-operations and dynamically issuing those micro-operations, i.e. indirect and dynamic superscalar execution; the Pentium Pro and AMD K5 are early examples of this. It allows a fairly simple superscalar design to be located after the (fairly complex) decoders (and buffers), giving, so to speak, the best of both worlds in many respects. This technique is also used in IBM z196 and later z/Architecture microprocessors.

CISC and RISC terms
The terms CISC and RISC have become less meaningful with the continued evolution of both CISC and RISC designs and implementations. The first highly (or tightly) pipelined x86 implementations, the 486 designs from Intel, AMD, Cyrix, and IBM, supported every instruction that their predecessors did, but achieved maximum efficiency only on a fairly simple x86 subset that was only a little more than a typical RISC instruction set (i.e., without typical RISC load–store limits). The Intel P5 Pentium generation was a superscalar version of these principles. However, modern x86 processors also (typically) decode and split instructions into dynamic sequences of internally buffered micro-operations, which helps execute a larger subset of instructions in a pipelined (overlapping) fashion, and facilitates more advanced extraction of parallelism out of the code stream, for even higher performance.

Contrary to popular simplifications (present also in some academic texts,) not all CISCs are microcoded or have "complex" instructions. As CISC became a catch-all term meaning anything that's not a load–store (RISC) architecture, it's not the number of instructions, nor the complexity of the implementation or of the instructions, that define CISC, but that arithmetic instructions also perform memory accesses. Compared to a small 8-bit CISC processor, a RISC floating-point instruction is complex. CISC does not even need to have complex addressing modes; 32- or 64-bit RISC processors may well have more complex addressing modes than small 8-bit CISC processors.

A PDP-10, a PDP-8, an Intel 80386, an Intel 4004, a Motorola 68000, a System z mainframe, a Burroughs B5000, a VAX, a Zilog Z80000, and a MOS Technology 6502 all vary widely in the number, sizes, and formats of instructions, the number, types, and sizes of registers, and the available data types. Some have hardware support for operations like scanning for a substring, arbitrary-precision BCD arithmetic, or transcendental functions, while others have only 8-bit addition and subtraction. But they are all in the CISC category. because they have "load-operate" instructions that load and/or store memory contents within the same instructions that perform the actual calculations. For instance, the PDP-8, having only 8 fixed-length instructions and no microcode at all, is a CISC because of how the instructions work, PowerPC, which has over 230 instructions (more than some VAXes), and complex internals like register renaming and a reorder buffer, is a RISC, while Minimal CISC has 8 instructions, but is clearly a CISC because it combines memory access and computation in the same instructions.

General references

 * Tanenbaum, Andrew S. (2006) Structured Computer Organization, Fifth Edition, Pearson Education, Inc. Upper Saddle River, NJ.

title: Complex instruction set computer


text:
CISC

CISC may refer to:

 * Caribbean Island Swimming Championships
 * Chongqing Iron and Steel Company
 * Clean intermittent self-catheterisation, a form of urinary catheterization
 * Complex instruction set computer
 * Criminal Intelligence Service Canada
 * CRTC Interconnection Steering Committee

title: CISC