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802.1z - Especificaciones y distancias SX - LX - ZX - LH

IEEE 802.3z - Especificación para Gigabit Ethernet
La especificación IEEE 802.3z incluye los siguientes protocolos de la capa física:• 1000BASE-CX: Operación Full-duplex sobre líneas de cobre. • 1000BASE-SX: Operación Full-duplex con dispositivos de longitud de onda corta(850-nanometer [nm]) sobre fibra óptica multimodo. • 1000BASE-LX: Operación Full-Duplex con dispositivos de longitud de onda larga (1300-nm) sobre fibra óptica multimodo o monomodo. • 1000BASE-ZX: Operación Full-duplex con dispositivos de longitud de onda extendida (1550-nm) sobre fibra óptica monomodo.
Distancias soportadas:• 1000BASE-CX: Si se utiliza cable UTP categoría 5, la distancia máxima es de 100 metros. • 1000BASE-SX: Hasta 550 metros, dependiendo del tipo de fibra que se utilice, según la tabla siguiente:Tipo de fibra - Ancho de banda Modal - Rango 62.5 micrómetros multimodo - 160 - 2 a 220 metros 62.5 micrómetros multimodo - 200 - 2 a 275 metros 50.0 micrómetros multimodo - 400 - 2 a 500 metros 50.0 micrómet…

"Octets" vs. "Bytes"

A: The distinction is subtle, but important. The term _byte_ refers to a computer-dependent character size, while _octet_ always means 8 bits (independent of the computer). I have worked on several computers that had odd byte sizes. For example, Purdue once had a CDC mainframe with 6-bit bytes, and I also used a BBN computer (the C machine) on which a byte contained 10 bits.

In practice, most computers have 8-bit bytes and most engineers and programmers mean ``an 8-bit quantity'' when they use the term _byte_. In a texbook, however, which can be read by people with various backgrounds and who use various computers, it is important to make the distinction

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There has been some disagreement, and even controversy, surrounding the use of the words byte and octet. The former term has traditionally been the most popular in common parlance for a set of eight bits, especially in North America. However, it is technically not…

MacArthur's Speeches: "I Shall Return."

This phrase -- among the more famous in American history -- is practically synonymous with Douglas MacArthur, known even to those who know nothing else about him. The last part of a simple statement to reporters shortly after his harrowing escape from Corregidor and arrival in Australia, it's pure MacArthur -- first-person, highly dramatic, and more political than meets the eye.

The President of the United States ordered me to break through the Japanese lines and proceed from Corregidor to Australia for the purpose, as I understand it, of organizing the American offensive against Japan, a primary objective of which is the relief of the Philippines. I came through and I shall return.

What happened in october 12th

Birthdates Which Occur on October 12:
1350 Dimitri "Donskoi" Ivanovitch great monarch of Vladimir-Soezdal
1490 Bernardo Pisano composer
1537 Edward VI Tudor, King of England (1547-53)
1606 Christoph B von Galen prince-bishop of M�nster (1650-78)
1686 Silvius Leopold Weiss composer
1713 Johann Ludwig Krebs composer
1742 Johan Peter Melchior German sculptor
1759 Frantisek Vaclav Tomes composer
1762 John W Janssens gov-gen of Cape colony/Dutch-Indies 1811
1763 John Ross composer
1798 A J Pedro I van Alcantara Kaiser of Brazil (1822-31)/king of Portugal
and Charles Albert King of Sardinia (1831-49)
1807 John Tideman Dutch Remonstrant theologist
1808 John Liptrot Hatton composer
1813 Lyman Trumbull MC (Union) died in 1896
1815 William Joseph Hardee Lt Gen (Confederate Army), died in 1873
1822 Joseph Haydn Potter Brig General (Union volunteers), died in 1892
1832 Walter T Watts-Dunton England, lawyer/poet/writer (Aylwin)
1840 Helena Modjeska Poland, Shakespearian actress (Juliet)/anti-Russian
1844 Ge…

First 3 linux messages

From:torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroup: comp.os.minix
Subject: GCC-1.40 and a posix question
Message-ID: 1991Jul13, 100050.9886@klaava.Helsinki.FI
Date: 3 Jul 91 10:00:50 GMT


Hello netlanders,
Due a project I'm working on (in minix), I'm interested
in the posix standard definition. Could somebody please
point me to a (preferably) machine-readable format of the
latest posix rules? Ftp-sites would be nice.


Linux Torvalds torvalds@kruuna.helsinki.fi
Aquí el que le siguió; este mensaje es considerado por muchos como el comienzo de Linux:
From:torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroup: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system
Message-ID: 1991Aug25, 20578.9541@klaava.Helsinki.FI
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki.


Hello everybody out there using minix-


I'm doing a (free) operating system (just a hobby, won't
be big and professional like gnu) f…

Linux History

Linus Torvalds: A Very Brief and
Completely Unauthorized Biography



Linus Torvalds is the world's most famous computer programmer and also its most famous Finn. He is the founder and coordinator of Linux, the Unix-like operating system that is beginning to revolutionize the computer industry and possibly much else as well. His is truly one of the great tales in the history of the computers.
Early Years

Linus Benedict Torvalds was born on December 28, 1969 in Helsinki, the capital and largest city in Finland. He was named after Linus Pauling, the famous physical chemist and Nobel Prize winner.

The Torvalds family belongs to the Swedish-speaking minority in Finland, which numbers about 300,000 in a total population of roughly five million.

Many members of the family were journalists. His parents, Nils and Anna Torvalds, were both radicals at the University of Helsinki during the 1960s. His father was a Communist who spent a year studying in Moscow in the mid-1970s and later became a radio …

Linux First Email

On August 25, 1991, he announced his initial creation on the MINIX newsgroup comp.os.minix as follows:

Message-ID: 1991Aug25.205708.9541@klaava.helsinki.fi
From: torvalds@klaava.helsinki.fi (Linus Benedict Torvalds)
To: Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system

Hello everybody out there using minix-

I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386 (486) AT clones. This has been brewing since april, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-sytem due to practical reasons)among other things.

I've currently ported bash (1.08) an gcc (1.40), and things seem to work. This implies that i'll get something practical within a few months, and I'd like to know what features most people want.

Any sugges…