Byte https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html.

Advanced Encryption Standard The SubBytes step
In the SubBytes step, each byte in the state matrix is replaced with a SubByte using an 8-bit substitution box, the Rijndael S-box

Checksum Parity byte or parity word
The simplest checksum algorithm is the so-called longitudinal parity check, which breaks the data into "words" with a fixed number n of bits, and then computes the exclusive or of all those words. The result is appended to the message as an extra word. To check the integrity of a message, the receiver computes the exclusive or of all its words, including the checksum; if the result is not a word with n zeros, the receiver knows that a transmission error occurred.

Checksum Parity byte or parity word
With this checksum, any transmission error that flips a single bit of the message, or an odd number of bits, will be detected as an incorrect checksum. However, an error that affects two bits will not be detected if those bits lie at the same position in two distinct words. If the affected bits are independently chosen at random, the probability of a two-bit error being undetected is 1/n..

Byte Not to be confused with Bite, Bight . This article is about the unit of information. For other uses, see Byte .

Byte The de facto standard of eight bits is a convenient power of two permitting the values 0 through 255 for one byte

Byte The unit octet was defined to explicitly denote a sequence of 8 bits because of the ambiguity associated at the time with the byte.

Byte History The term byte was coined by Werner Buchholz in July 1956, during the early design phase for the IBM Stretch computer. It is a deliberate respelling of bite to avoid accidental mutation to bit.

Byte History Early computers used a variety of 4-bit binary coded decimal (BCD) representations and the 6-bit codes for printable graphic patterns common in the U.S

Byte History In the early 1960s, AT&T introduced digital telephony first on long-distance trunk lines. These used the 8-bit µ-law encoding. This large investment promised to reduce transmission costs for 8-bit data. The use of 8-bit codes for digital telephony also caused 8-bit data octets to be adopted as the basic data unit of the early Internet.

Byte History The development of 8-bit microprocessors in the 1970s popularized this storage size

Byte History The term octet is used to unambiguously specify a size of eight bits, and is used extensively in protocol definitions, for example.

Byte Unit symbol The unit symbol for the byte is specified in IEC , IEEE 1541 and the Metric Interchange Format as the upper-case character B.

the decibyte, is never used.
Byte Unit symbol the decibyte, is never used.

Byte Unit symbol The unit symbol kB is commonly used for kilobyte, but may be confused with the still often-used abbreviation of kb for kilobit. IEEE 1541 specifies the lower case character b as the symbol for bit; however, IEC and Metric-Interchange-Format specify the abbreviation bit (e.g., Mbit for megabit) for the symbol, providing disambiguation from B for byte.

Byte Unit symbol The lowercase letter o for octet is defined as the symbol for octet in IEC and is commonly used in several non-English languages (e.g., French and Romanian), and is also used with metric prefixes (for example, ko and Mo)

Byte Unit multiples Considerable confusion exists about the meanings of the SI (or metric) prefixes used with the unit byte, especially concerning prefixes such as kilo (k or K) and mega (M) as shown in the chart Prefixes for bit and byte

Byte Unit multiples While the numerical difference between the decimal and binary interpretations is relatively small for the prefixes kilo and mega, it grows to over 20% for prefix yotta, illustrated in the linear-log graph (at right) of difference versus storage size.

Byte Common uses The C# programming language, along with other .NET-languages, has both the unsigned byte (named byte) and the signed byte (named sbyte), holding values from 0 to 255 and -128 to 127, respectively.

Byte Common uses In addition, the C and C++ standards require that there are no "gaps" between two bytes. This means every bit in memory is part of a byte.

Byte Common uses In data transmission systems, a byte is defined as a contiguous sequence of binary bits in a serial data stream, such as in modem or satellite communications, which is the smallest meaningful unit of data. These bytes might include start bits, stop bits, or parity bits, and thus could vary from 7 to 12 bits to contain a single 7-bit ASCII code.

Emacs Lisp - Byte code "Byte-compilation" can make Emacs Lisp code faster. Emacs contains a compiler which can translate Emacs Lisp source files into a special representation known as bytecode. Emacs Lisp bytecode files have the filename suffix ".elc". Compared to source files, bytecode files load faster, occupy less space on the disk, use less memory when loaded, and run faster.

Emacs Lisp - Byte code Bytecode still runs more slowly than primitives, but functions loaded as bytecode can be easily modified and re-loaded. In addition, bytecode files are platform-independent. The standard Emacs Lisp code distributed with Emacs is loaded as bytecode, although the matching source files are usually provided for the user's reference as well. User-supplied extensions are typically not byte-compiled, as they are neither as large nor as computationally intensive.

DEC Alpha - Byte-Word Extensions (BWX)
Later, the Alpha included byte-word extensions, a set of instructions to manipulate 8-bit and 16-bit data types

LDBU Load Zero-Extended Byte from Memory to Register

LDWU Load Zero-Extended Word from Memory to Register

Integer (computer science) - Bytes and octets
The term byte initially meant 'the smallest addressable unit of memory'. In the past, 5-, 6-, 7-, 8-, and 9-bit bytes have all been used. There have also been computers that could address individual bits ('bit-addressed machine'), or that could only address 16- or 32-bit quantities ('word-addressed machine'). The term byte was usually not used at all in connection with bit- and word-addressed machines.

The term octet always refers to an 8-bit quantity. It is mostly used in the field of computer networking, where computers with different byte widths might have to communicate.

In modern usage byte almost invariably means eight bits, since all other sizes have fallen into disuse; thus byte has come to be synonymous with octet.

Machine code - Relationship to bytecode
Machine code should not be confused with so-called "bytecode" (or the older term p-code), which is either executed by an interpreter or itself compiled into machine code for faster (direct) execution. Machine code and assembly code is sometimes called native code when referring to platform-dependent parts of language features or libraries.

Data rate units - Decimal multiples of bytes
WARNING: These units are often not used in the suggested ways! See above section titled "variations".

Data rate units - Kilobyte per second
A kilobyte per second -kBps or kB/s- is a unit of data transfer rate equal to:

Data rate units - Megabyte per second
A megabyte per second -MBps or MB/s- (not to be confused with Mbps or Mb/s, which would be megabits per second) is a unit of data transfer rate equal to:

Data rate units - Gigabyte per second
A gigabyte per second -GBps or GB/s- is a unit of data transfer rate equal to:

Data rate units - Terabyte per second
A terabyte per second -TBps or TB/s- is a unit of data transfer rate equal to:

Data rate units - Binary multiples of bytes
For more details on prefixes such as kibi-, mebi-, gibi-, and tebi-, see Binary prefix.

Data rate units - Kibibyte per second
A kibibyte per second (KiB/s) is a unit of data transfer rate equal to:

Data rate units - Mebibyte per second
A mebibyte per second (MiB/s) is a unit of data transfer rate equal to:

Data rate units - Gibibyte per second
A gibibyte per second (GiB/s) is a unit of data transfer rate equal to:

Data rate units - Tebibyte per second
A tebibyte per second (TiB/s) is a unit of data transfer rate equal to:

Categories Computer magazines
Byte (magazine) Categories Computer magazines

Country United States Byte (magazine)

Byte (magazine) The Byte name and logo continued to exist as of 2011, but as an online publication only, with different emphasis.

Byte (magazine) Byte started in 1975, shortly after the first personal computers appeared as kits advertised in the back of electronics magazines. Byte was published monthly, with an initial yearly subscription price of $10.

Byte (magazine) - Foundation
In 1975 Wayne Green was the editor and publisher of 73 (an amateur radio magazine) and his ex-wife, Virginia Londner Green was the Business Manager of 73 Inc. In the August 1975 issue of 73 magazine Wayne's editorial column started with this item:

The response to computer-type articles in 73 has been so enthusiastic that we here in Peterborough got carried away. On May 25th we made a deal with the publisher of a small (400 circulation) computer hobby magazine to take over as editor of a new publication which would start in August ... Byte.

Carl wrote to another hobbyist newsletter, Micro-8 Computer User Group Newsletter, and described his new job as editor of Byte magazine.

I got a note in the mail about two weeks ago from Wayne Green, publisher of '73 Magazine' essentially saying hello and why don't you come up and talk a bit. The net result of a follow up is the decision to create BYTE magazine using the facilities of Green Publishing Inc. I will end up with the editorial focus for the magazine; with the business end being managed by Green Publishing.

Virginia Londner Green had returned to 73 in the December 1974 issue and incorporated Green Publishing in March The first five issues of Byte were published by Green Publishing and the name was changed to Byte Publications starting with the February 1976 issue. Carl Helmers was a co-owner of Byte Publications.

The first 4 issues were produced in the offices of 73 and Wayne Green was listed as the publisher. One day in November 1975 Wayne came to work and found that the Byte magazine staff had moved out and taken the January issue with them. The February 1976 issue of Byte has a short story about the move. "After a start which reads like a romantic light opera with an episode or two reminiscent of the Keystone Cops, Byte magazine finally has moved into separate offices of its own."

Wayne Green was not happy about losing Byte magazine so he was going to start a new one called Kilobyte. Byte quickly trademarked KILOBYTE as a cartoon series in Byte magazine. The new magazine was called Kilobaud. There was competition and animosity between Byte Publications and 73 Inc. but both remained in the small town of Peterborough, New Hampshire.

Byte (magazine) - The early years
Byte was able to attract advertising and articles from many well-knowns, soon-to-be-well-knowns, and ultimately-to-be-forgottens in the growing microcomputer hobby. Articles in the first issue (September, 1975) included Which Microprocessor For You? by Hal Chamberlin, Write Your Own Assembler by Dan Fylstra and Serial Interface by Don Lancaster. Advertisements from Godbout, MITS, Processor Technology, SCELBI, and Sphere appear, among others.

Byte (magazine) - The early years
Byte ran Microsoft's first advertisement, as "Micro-Soft", to sell a BASIC interpreter for 8080-based computers.

Byte (magazine) - Growth and change
By the early 1980s BYTE had become an "elite" magazine, seen as a peer of Rolling Stone and Playboy, and others such as David Bunnell of PC Magazine aspired to emulate its reputation and success

From 1975 through 1986 Byte covers usually featured the artwork of Robert Tinney. These covers made Byte visually unique. In 1987 Tinney's paintings were replaced by product photographs, and Steve Ciarcia's "Circuit Cellar" column was discontinued.

Many of the Byte staff were active on the service

Byte continued to grow. By 1990 it was a monthly about an inch in thickness, a readership of technical professionals, and a subscription price of $56/year, a high figure for the time. It was the "must-read" magazine of the popular computer magazines. Around 1993 Byte began to develop a web presence. It acquired the domain name byte.com and began to have discussions and post selected editorial content.

It developed a number of national sister editions in Japan, Brazil, Germany, and an Arabic edition published in Jordan.

Byte (magazine) - End of the printed magazine, and online publication
The magazine's editors and writers expected its new owner to revitalize Byte but CMP ceased publication with the July 1998 issue, laid off all the staff and shut down Byte's rather large product-testing lab

Publication of Byte in Germany and Japan continued uninterrupted. The Turkish edition resumed publication after a few years of interruption. The Arabic edition also ended abruptly.

In 1999 CMP revived Byte as a web-only publication, from 2002 accessible by subscription

Byte (magazine) - The launch of byte.com
UBM TechWeb brought the Byte name back when it officially relaunched Byte as byte.com on 11 July According to the site, the mission of the new Byte is:

"...to examine technology in the context of the consumerization of IT

The byte.com launch editor was tech journalist Gina Smith. On September 26, 2011 Smith was replaced by Larry Seltzer.

In January, 2012 American science fiction and horror author F. Paul Wilson began writing for byte.com, mostly in the persona of his best-known character Repairman Jack.

In April 2013, byte.com stopped being updated.

As of October 2013, byte.com redirects to which in turn redirects to -- there is no byte.com branding or mention of Byte or byte.com anywhere on the page the browser is ultimately redirected to.

UTF-16 - Byte order encoding schemes
UTF-16 and UCS-2 produce a sequence of 16-bit code units. Each unit thus takes two 8-bit bytes, and the order of the bytes may depend on the endianness (byte order) of the computer architecture.

This incorrect result provides a hint to perform byte-swapping for the remaining values

The standard also allows the byte order to be stated explicitly by specifying UTF-16BE or UTF-16LE as the encoding type. When the byte order is specified explicitly this way, a BOM is specifically not supposed to be prepended to the text, and a U+FEFF at the beginning should be handled as a ZWNBSP character. Many applications ignore the BOM code at the start of any Unicode encoding. Web browsers often use a BOM as a hint in determining the character encoding.

For Internet protocols, IANA has approved "UTF-16", "UTF-16BE", and "UTF-16LE" as the names for these encodings. (The names are case insensitive.) The aliases UTF_16 or UTF16 may be meaningful in some programming languages or software applications, but they are not standard names in Internet protocols.

UCS-2 encoding is defined to be big-endian only. In practice most software defaults to little-endian, and handles a leading BOM to define the byte order just as in UTF-16. Although the similar designations UCS-2BE and UCS-2LE imitate the UTF-16 labels, they do not represent official encoding schemes.

Exabyte The exabyte is a multiple of the unit byte for digital information. The prefix exa indicates the sixth power of 1,000 and means 1018 in the International System of Units (SI), and therefore 1 exabyte is one quintillion bytes (short scale). The unit symbol for the exabyte is EB.

Exabyte - Usage examples
In principle, the 64-bit microprocessors found in many computers can address 16 exabytes of memory.

The world's technological capacity to store information grew from 2.6 (optimally compressed) exabytes in 1986 to 15.8 in 1993, over 54.5 in 2000, and to 295 (optimally compressed) exabytes in 2007

The world’s technological capacity to receive information through one-way broadcast networks was 432 exabytes of (optimally compressed) information in 1986, 715 (optimally compressed) exabytes in 1993, 1,200 (optimally compressed) exabytes in 2000, and 1,900 in 2007.

The world's effective capacity to exchange information through two-way telecommunication networks was exabytes of (optimally compressed) information in 1986, in 1993, 2.2 in 2000, and 65 (optimally compressed) exabytes in 2007.

In 2004, the global monthly Internet traffic passed 1 exabyte for the first time. In January 2007, Bret Swanson of the Discovery Institute coined the term exaflood for a supposedly impending flood of exabytes that would cause the Internet's congestive collapse. Nevertheless, the global Internet traffic has continued its exponential growth, undisturbed, and as of March 2010 it is estimated at 21 exabytes per month.

According to the June 2009 Cisco Visual Networking Index IP traffic forecast, global mobile data traffic will grow at a CAGR of 131 percent between 2008 and 2013, reaching over two exabytes per month by 2013.

According to the 2011 update of Cisco's VNI IP traffic forecast, by 2015, annual global IP traffic will reach 966 exabytes or nearly one full zettabyte. Internet video will account for 61% of total Internet data.

According to the February 2013 update of Cisco VNI Forecast for 2012–17, annual global IP traffic will pass the zettabyte threshold by the end of In 2016 global IP traffic will reach 1.3 zettabytes per year or exabytes per month. By 2017 global mobile data traffic will reach 11.2 exabytes per month (134 exabytes annually); growing 13-fold from 2012 to 2017.

According to an IDC paper sponsored by EMC Corporation, 161 exabytes of data were created in 2006, "3 million times the amount of information contained in all the books ever written", with the number expected to hit 988 exabytes in 2010.

According to the CSIRO, in the next decade, astronomers expect to be processing 10 petabytes of data every hour from the Square Kilometre Array (SKA) telescope. The array is thus expected to generate approximately one exabyte every four days of operation. According to IBM, the new SKA telescope initiative will generate over an exabyte of data every day. IBM is designing hardware to process this information.

According to the Digital Britain Report, 494 exabytes of data was transferred across the globe on June 15, 2009.

Several filesystems use disk formats that support theoretical volume sizes of several exabytes, including Btrfs, XFS, ZFS, exFAT, NTFS, HFS Plus, and ReFS.

The ext4 file system format supports volumes up to 1 exabyte in size, although the userspace tools cannot yet administer such filesystems.

Oracle Corporation claimed the first exabyte tape library with the SL8500 and the T10000C tape drive in January 2011.

Exabyte - All words ever spoken
Mark Liberman calculated the storage requirements for all human speech at 42 zettabytes (42,000 exabytes, and 8,400 times the original estimate), if digitized as 16 kHz 16-bit audio, although he did freely confess that "maybe the authors [of the exabyte estimate] were thinking about text".

Exabyte - All words ever spoken
Research from University of Southern California estimates that the amount of data stored in the world by 2007 was 295 exabytes and the amount of information shared on two-way communications technology, such as cell phones in 2007 as 65 exabytes.

Exabyte - 100,000 Libraries of Congress
The Library of Congress is commonly estimated at 10 terabytes for all printed material. Recent estimates of the size including audio, video, and digital materials is from 3 petabytes to 20 petabytes.

Exabyte - 100,000 Libraries of Congress
So, an exabyte could hold a hundred thousand times all the printed material, or 500 to 3,000 times all content of the Library of Congress.

MIME - Byteranges The multipart/byterange is used to represent noncontiguous byte ranges of a single message. It is used by HTTP when a server returns multiple byte ranges and is defined in RFC 2616.

Bytecode Bytecode, also known as p-code (portable code), is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normally numeric addresses) which encode the result of parsing and semantic analysis of things like type, scope, and nesting depths of program objects. They therefore allow much better performance than direct interpretation of source code.

Bytecode Bytecode may often be either directly executed on a virtual machine (i.e

Bytecode Since bytecode instructions are processed by software, they may be arbitrarily complex, but are nonetheless often akin to traditional hardware instructions; virtual stack machines are the most common, but virtual register machines have also been built. Different parts may often be stored in separate files, similar to object modules, but dynamically loaded during execution.

Bytecode - Execution This introduces a delay before a program is run, when bytecode is compiled to native machine code, but improves execution speed considerably compared to direct interpretation of the source code—normally by several magnitudes.

Bytecode - Execution There are bytecode based virtual machines of this sort for Java, Python, PHP, Tcl, and Forth (however, Forth is not ordinarily compiled via bytecodes in this way, and its virtual machine is more generic instead)

Bytecode - Execution More recently, the authors of the V8 and Dart languages have challenged the notion that intermediate bytecode is a necessity for fast and efficient VM implementation. Both of these language implementations currently do direct JIT compilation from source code to machine code without any bytecode intermediary.

Bytecode - Examples ActionScript executes in the ActionScript Virtual Machine (AVM), which is part of Flash Player and AIR. ActionScript code is typically transformed into bytecode format by a compiler. Examples of compilers include the one built into Adobe Flash Professional and the one that is built into Adobe Flash Builder and available in the Adobe Flex SDK.

Bytecode - Examples BANCStar, originally bytecode for an interface-building tool but used as a language in its own right.

C to Java Virtual Machine compilers
Bytecode - Examples C to Java Virtual Machine compilers

Bytecode - Examples CMUCL and Scieneer Common Lisp implementations of Common Lisp can compile either to bytecode or to native code; bytecode is much more compact

Bytecode - Examples Dalvik bytecode, designed for the Android platform, is executed by the Dalvik virtual machine.

Bytecode - Examples Dis bytecode, designed for the Inferno (Operating System), is executed by the Dis virtual machine.

EiffelStudio for the Eiffel programming language
Bytecode - Examples EiffelStudio for the Eiffel programming language

Bytecode - Examples Emacs is a text editor with a majority of its functionality implemented by its specific dialect of Lisp. These features are compiled into bytecode. This architecture allows users to customize the editor with a high level language, which after compilation into bytecode yields reasonable performance.

Ericsson implementation of Erlang uses BEAM bytecodes
Bytecode - Examples Ericsson implementation of Erlang uses BEAM bytecodes

Icon and Unicon programming languages
Bytecode - Examples Icon and Unicon programming languages

Bytecode - Examples Infocom used the Z-machine to make its software applications more portable.

Java bytecode, which is executed by the Java Virtual Machine
Bytecode - Examples Java bytecode, which is executed by the Java Virtual Machine

LLVM, a modular bytecode compiler and virtual machine
Bytecode - Examples LLVM, a modular bytecode compiler and virtual machine

Lua uses a register-based bytecode virtual machine.
Bytecode - Examples Lua uses a register-based bytecode virtual machine.

m-code of the MATLAB programming language
Bytecode - Examples m-code of the MATLAB programming language

Bytecode - Examples Managed code such as Microsoft .NET Common Intermediate Language, executed by the .NET Common Language Runtime (CLR)

O-code of the BCPL programming language
Bytecode - Examples O-code of the BCPL programming language

Bytecode - Examples OCaml programming language optionally compiles to a compact bytecode form

Bytecode - Examples p-code of UCSD Pascal implementation of the Pascal programming language

Parrot virtual machine
Bytecode - Examples Parrot virtual machine

Bytecode - Examples The R environment for statistical computing offers a byte code compiler through the compiler package, now standard with R version It is possible to compile this version of R so that the base and recommended packages take advantage of this.

Scheme 48 implementation of Scheme using bytecode interpreter
Bytecode - Examples Scheme 48 implementation of Scheme using bytecode interpreter

Bytecode - Examples Bytecodes of many implementations of the Smalltalk programming language

The SPIN interpreter built into the Parallax Propeller Microcontroller
Bytecode - Examples The SPIN interpreter built into the Parallax Propeller Microcontroller

Visual FoxPro compiles to bytecode
Bytecode - Examples Visual FoxPro compiles to bytecode

UTF-8 - Invalid byte sequences
Not all sequences of bytes are valid UTF-8. A UTF-8 decoder should be prepared for:

an unexpected continuation byte

a start byte not followed by enough continuation bytes

A 4-byte sequence (starting with 0xF4) that decodes to a value greater than U+10FFFF

Many earlier decoders would happily try to decode these. Carefully crafted invalid UTF-8 could make them either skip or create ASCII characters such as NUL, slash, or quotes. Invalid UTF-8 has been used to bypass security validations in high profile products including Microsoft's IIS web server and Apache's Tomcat servlet container.

RFC 3629 states "Implementations of the decoding algorithm MUST protect against decoding invalid sequences." The Unicode Standard requires decoders to "...treat any ill-formed code unit sequence as an error condition. This guarantees that it will neither interpret nor emit an ill-formed code unit sequence."

Many UTF-8 decoders throw exceptions on encountering errors. This can turn what would otherwise be harmless errors (producing a message such as "no such file") into a denial of service bug. For instance, Python 3.0 would exit immediately if the command line or environment variables contained invalid UTF-8, so it was impossible for any Python program to detect and recover from such an error.

An increasingly popular option is to detect errors with a separate API, and for converters to translate the first byte to a replacement and continue parsing with the next byte. These error bytes will always have the high bit set. Popular replacements include:

The invalid Unicode code points U+DC80..U+DCFF where the low 8 bits are the byte's value.

The Unicode code points U U+00FF with the same value as the byte, thus interpreting the bytes according to ISO

The Unicode code point for the character represented by the byte in CP1252. This is similar to using ISO , except that some characters in the range 0x80..0x9F are mapped into different Unicode code points. For example, 0x80 becomes the Euro sign, U+20AC.

These replacement algorithms are "lossy": an invalid string is converted to the same sequence of code points that a valid UTF-8 string could have.

UTF-8 - Byte order mark Software that is not aware of multibyte encodings will display the BOM as three strange characters (e.g

UTF-8 - Byte order mark The Unicode Standard neither requires nor recommends the use of the BOM for UTF-8. The presence of the UTF-8 BOM may cause interoperability problems with existing software that could otherwise handle UTF-8; for example:

UTF-8 - Byte order mark Programming language parsers not explicitly designed for UTF-8 can often handle UTF-8 in string constants and comments, but cannot parse the BOM at the start of the file.

UTF-8 - Byte order mark Programs that identify file types by leading characters may fail to identify the file if a BOM is present even if the user of the file could skip the BOM. An example is the Unix shebang syntax. Another example is Internet Explorer which will render pages in standards mode only when it starts with a document type declaration.

UTF-8 - Byte order mark Programs that insert information at the start of a file will break use of the BOM to identify UTF-8 (one example is offline browsers that add the originating URL to the start of the file).

UTF-8 - Byte order mark If compatibility with existing programs is not important, the BOM could be used to identify UTF-8 encoding, but such use should not be necessary as UTF-8 can be identified with very high reliability since other encodings are extremely unlikely to contain valid UTF-8 byte sequences.

Interpreted language - Languages usually compiled to a bytecode
Many interpreted languages are first compiled to bytecode, which is normally interpreted by virtual machine exploiting some just-in-time compilation of bytecode to native code. However, sometimes, bytecode can also be compiled to a native binary using an AOT compiler) or executed natively, by hardware processor.

Interpreted language - Languages usually compiled to a bytecode
.NET Framework languages (translated to bytecode, called CIL). CIL was designed to be fully JIT compiled, yet, CIL interpreters are known, including hardware attempts.

Lego Mindstorms NXT - BricxCC, Next Byte Codes, Not eXactly C
Bricx Command Center (BricxCC) is the integrated development environment (IDE) used to write, compile, and edit NBC and NXC programs for the NXT. Also, as BricxCC was originally made for the RCX, programs for it can be written using NQC via BricxCC. Different firmwares can be flashed to the NXT using BricxCC.

BricxCC has many utilities such as NeXTExplorer (upload/download files, defragment the NXT, use file hex viewer), NeXTScreen (view what's on the NXT's LCD display, and capture images and video).

Next Byte Codes (NBC) is a simple open source language with an assembly language syntax that can be used to program the NXT brick. BricxCC also has the capability to decompile standard .rxe NXT executables to NBC

Not eXactly C (NXC) is a high level open-source language, similar to C, built on the NBC compiler. It can also be used to program the NXT brick. NXC is basically NQC for the NXT. It is one of the most widely used third-party programming languages for the NXT. In NXC, even creating video games for the NXT is possible. Some people have even got working grayscale on the NXT Screen.

Megabyte The megabyte (symbol MB, sometimes abbreviated as Mbyte) is a multiple of the unit byte for digital information storage or transmission with three different values depending on context: bytes (106, see prefix mega-) generally for computer storage or transmission rates; bytes (220, or a mebibyte) generally for computer memory; and in rare cases 1000×1024 ( ) bytes.

Megabyte - Definitions
Nevertheless, the term megabyte continues to be widely used with different meanings:

1 MB = bytes (= B = 106 B) is the definition recommended by the International System of Units (SI) and the International Electrotechnical Commission IEC

1 MB = bytes (= B = 220 B) is the definition used by Microsoft Windows in reference to computer memory (e.g. RAM). See Consumer confusion (in the "gigabyte" article). This definition is synonymous with the unambiguous IEC standard name mebibyte.

1 MB = bytes (= 1000×1024) B is the definition used to describe the formatted capacity of the "1.44 MB" 3.5 inch HD floppy disk, which actually has a capacity of bytes.

Sector sizes were set as powers of two (most common 512 bytes or 4096 bytes) for convenience in processing

Megabyte - Examples of use
Depending on compression methods and file format, a megabyte of data can roughly be:

a 4 megapixel JPEG image with normal compression is about 1 MB in size.

About 1 minute of 128 kbit/s MP3 compressed music.

6 seconds of uncompressed CD audio.

a typical English book volume in plain text format (500 pages × 2000 characters per page).

The human genome consists of DNA representing 800 MB of data. The parts that differentiate one person from another can be losslessly compressed to 4 MB.

Exabyte (company) At the time of its demise, Exabyte manufactured VXA and LTO based products

Exabyte (company) - Corporate history
The company was formed in 1985 by Juan Rodriguez, Harry Hinz, and Kelly Beavers, and a group of ex-StorageTek engineers who were interested in using consumer videotape technology for data storage. The company advanced technology for computer backups in 1987 when they introduced the Data8 magnetic tape format. The company's follow-up technologies, including Mammoth and Mammoth-2, were less successful.

Exabyte (company) - Corporate history
Exabyte went public on the NASDAQ in 1989 under the symbol EXBT.

Exabyte (company) - Acquisitions
Exabyte's history of acquisitions includes:

Tallgrass Technologies of Lenexa, KS. Tallgrass manufactured 4mm DDS drives, backup software, and had a significant distribution channel.

Everex's Mass Storage Division (MSD). Everex did its research and development in Ann Arbor, MI and manufactured its products in Fremont, CA. Everex MSD made QIC products.

October Grundig Data Scanner GmbH, for $2.9 million and renamed Exabyte Magnetics GmbH. This subsidiary designed and manufactured helical scan tape heads.

Exabyte (company) - Ecrix merger
Ecrix was a magnetic tape data storage company founded in 1996 in Boulder, Colorado. The founders, Kelly Beavers and Juan Rodriguez, were two of the three founders of Exabyte. The research and development done by Ecrix focused on making a cheaper 8mm tape drive. In 1999, Ecrix released their first product, the VXA tape drive. In 2001, Ecrix and Exabyte merged, giving Exabyte access to Ecrix's VXA Packet Technology tape drive format.

Exabyte (company) - Demise
On 30 June 2006, Exabyte announced that they are looking for a buyer.

On 30 August 2006, Tandberg Data announced that they were buying Exabyte's assets for 28 million USD.

The acquisition was completed on 20 November 2006.

Kilobyte - Definitions
Nevertheless, the term kilobyte continues to be widely used with the following two meanings:

Kilobyte - Decimal (base 10) definition
1 kB = 1000bytes = 103 bytes is the definition recommended by the International Electrotechnical Commission (IEC)

Kilobyte - Binary (base 2) definition
1 KB (or KiB) = 1024bytes = 210 bytes is the definition used by Microsoft Windows and Linux for computer memory, e.g., RAM. In the unambiguous IEC standard the unit for this amount of information is one kibibyte.

Kilobyte - Examples The HP 21MX real-time computer (1974) denoted 196,608 (which is 192×1024) as "196K", while the HP 3000 business computer (1973) denoted 131,072 (which is 128×1024) as "128K".

Kilobyte - Examples The Shugart SA ⁄4-inch floppy disk (1976) held 109,375 bytes unformatted, and was advertised as "110 Kbyte", using the 1000 convention. Likewise, the 8-inch DEC RX01 floppy (1975) held 256,256 bytes formatted, and was advertised as "256k". On the other hand, the Tandon 51⁄4-inch DD floppy format (1978) held 368,640 (which is 360×1024) bytes, but was advertised as "360 KB", following the 1024 convention.

Kilobyte - Examples On modern systems, Mac OS X Snow Leopard represents a 65,536 byte file as "66 KB", rounding to the nearest 1000, while Microsoft Windows 7 would divide by 1024 and represent this as "64 KB".

Kilobyte - Examples In December 1998, the IEC addressed such multiple usages and definitions by creating unique binary prefixes to denote multiples of 1024, such as “kibibyte (KiB)”, which represents 210, or 1024, bytes.

Kilobyte - Notes Jump up ^ Kilobyte – Definition and More from the Free Merriam-Webster Dictionary. Merriam-webster.com ( ). Retrieved on

Kilobyte - Notes Jump up ^ Kilobyte | Define Kilobyte at Dictionary.com. Dictionary.reference.com ( ). Retrieved on

Kilobyte - Notes Jump up ^ definition of kilobyte from Oxford Dictionaries Online. Askoxford.com. Retrieved on

Kilobyte - Notes Jump up ^ Prefixes for Binary Multiples — The NIST Reference on Constants, Units, and Uncertainty

Kilobyte - Notes Jump up ^ SanDisk USB Flash Drive "Note: 1 megabyte (MB) = 1 million bytes; 1 gigabyte (GB) = 1 billion bytes."

Kilobyte - Notes Jump up ^ "How Mac OS X reports drive capacity". Apple Inc Retrieved

Kilobyte - Notes The rest of the computer world, including the programmers who write Linux, thinks of a kilobyte as 1,024 bytes (2^10 bytes), a megabyte as 1,048,576 bytes(2^20), and a gigabyte as 1,073,741,824 bytes(2^30), which means that you're buying just a bit less than you might think."

Kilobyte - Notes Jump up ^ Frankenberg, Robert (October 1974). "All Semiconductor Memory Selected for New Minicomputer Series" (PDF). Hewlett-Packard Journal (Hewlett-Packard) 26 (2): pg 15–20. Retrieved "196K-word memory size"

Kilobyte - Notes Jump up ^ Hewlett-Packard (November 1973). "HP 3000 Configuration Guide" (PDF). HP 3000 Computer System and Subsystem Data: pg 59. Retrieved

Jump up ^ http://www.swtpc.com/mholley/SA400/SA400_Index.htm
Kilobyte - Notes Jump up ^

Kilobyte - Notes Jump up ^

Kilobyte - Notes Jump up ^ National Institute of Standards and Technology. "Prefixes for binary multiples". "In December 1998 the International Electrotechnical Commission (IEC) [...] approved as an IEC International Standard names and symbols for prefixes for binary multiples for use in the fields of data processing and data transmission."

Interpreter (computing) - Bytecode interpreters
The same approach is used with the Forth code used in Open Firmware systems: the source language is compiled into "F code" (a bytecode), which is then interpreted by a virtual machine.

Interpreter (computing) - Bytecode interpreters
Control tables - that do not necessarily ever need to pass through a compiling phase - dictate appropriate algorithmic control flow via customized interpreters in similar fashion to bytecode interpreters.

POSIX - 512- vs 1024-byte blocks
Stallman|Richard Stallman and the GNU team were implementing POSIX for the GNU operating system, they objected to this on the grounds that most people think in terms of 1024 byte (or 1 Kibibyte|KiB) blocks

Gibibyte The 'gibibyte' (symbol 'GiB') is a unit of Computer data storage|digital information storage. It is a binary prefix|binary multiple of the byte (symbol 'B') obtained using the prefix gibi-|gibi (symbol 'Gi').

Gibibyte The gibibyte is closely related to the gigabyte|gigabyte (GB), which is defined as 109 bytes = , but has been used as a synonym for gibibyte in some contexts (see binary prefix). In terms of standard gigabytes, = gibibytes are equal to one tebibyte.

Gibibyte Binary prefixes are increasingly used in scientific literature and open source software. In product advertising and other non-scientific publications, the kilobyte sometimes refers to a power of ten and sometimes a power of two.

Gigabyte The 'gigabyte' ( or The word 'gigabyte' can be pronounced two ways as well as its prefix. ) is a multiple of the unit byte for Computer data storage|digital information storage.

Gigabyte The SI prefix|prefix giga-|giga means 109 in the International System of Units (SI), therefore in this context 1 gigabyte is . The unit symbol for the gigabyte is 'GB'.

Gigabyte Historically, the term has also been used in some fields of computer science and information technology to denote the gibibyte, or (10243 or 230) bytes. For instance, JEDEC_memory_standards#Redefinition_of_some_standard_SI_prefixes|GB is so defined for computer memory by JEDEC a semiconductor trade and engineering society.

Gigabyte File systems and software often list file sizes or free space in some mixture of SI units and binary units; they sometimes use SI prefixes to refer to binary interpretation – that is using a label of gigabyte or GB for a number computed in terms of gibibytes (GiB), continuing the confusion.

Gigabyte In order to address this, the International Electrotechnical Commission has been promoting the use of the term gibibyte for the binary definition

Gigabyte - Definition Nevertheless, the term gigabyte continues to be widely used with the following two different meanings:

Gigabyte - Base 10 definition
Megabyte (MB) = 1,000,000 bytes; 1 Gigabyte (GB) = 1,000,000,000 bytes; 1TB = 1,000,000,000,000 bytes and DVDs, and is also consistent with the other uses of the SI prefix in computing, such as Megahertz#Megahertz in computing|CPU clock speeds or FLOPS|measures of performance

Gigabyte - Base 2 definition
* 1 GiB = bytes (= B = 230 B) is the definition used by Microsoft Windows in reference to computer memory (e.g., RAM). This definition is synonymous with the unambiguous IEC standard name gibibyte.

Gigabyte - Consumer confusion
Although most manufacturers of hard disk drives and flash-memory disk devices define 1 gigabyte as , software like Microsoft Windows reports size in gigabytes by dividing the total capacity in bytes by (230 = 1 gibibyte), while still reporting the result with the symbol GB

(meaning ) might be reported by the Operating System as only (meaning 372 GiB). Other software, like Mac OS X 10.6 and some components of the Linux kernel measure using the decimal units.

The JEDEC memory standards uses the IEEE 100 nomenclatures which defines a gigabyte as (or 230 bytes).

The difference between units based on decimal and binary prefixes increases as a Semilog|semi-logarithmic (linear-log) function—for example, the decimal kilobyte value is nearly 98% of the kibibyte, a megabyte is under 96% of a mebibyte, and a gigabyte is just over 93% of a gibibyte value

Because of its physical design, the capacity of modern computer internal memory devices such as DIMM modules is always a multiple of a power of It is thus convenient to use prefixes denoting powers of 1024, known as binary prefixes, in describing them. For example, a memory capacity of is conveniently expressed as 1gibibyte|GiB rather than as 1.074GB. The former specification is, however, almost always quoted as 1GB when applied to internal memory.

Software allocates memory in varying degrees of granularity as needed to fulfill data structure requirements and binary multiples are usually not required

Gigabyte - Examples of gigabyte-sized storage
* One hour of Standard-definition television|SDTV video at 2.2Mbit/s is approximately 1GB.

* Seven minutes of High-definition television|HDTV video at 19.39Mbit/s is approximately 1GB.

* 114 minutes of uncompressed Compact Disc|CD-quality audio at 1.4Mbit/s is approximately 1GB.

* A dual-layered Blu-ray disc can hold about 50GB.

Pebibyte The 'pebibyte' (symbol 'PiB') is a unit of Computer data storage|digital information storage. It is a binary prefix|binary multiple of the byte (symbol 'B') obtained using the prefix pebi-|pebi (symbol 'Pi').

Killobyte :This article is about the book. For the unit of information, see kilobyte. For the Marvel Comics supervillain, see Killobyte (comics).

Killobyte 'Killobyte' is a 1993 novel by Piers Anthony. This book explores a Virtual Reality world in the context of the Internet, and although originally intended as an action-adventure story, it is more of a character study. It is a cult favourite because of its forays into Virtual Reality, as well as its technical inaccuracies.

Killobyte - The game Killobyte is a second generation Virtual Reality game that puts players into a three-dimensional, fully sensory environment. Users are hooked up to a machine that not only simulates a range of sensations, from pain to sex, but responds to brain signals to move a player's character. The only way to exit the game and return to the real world is by selecting that option from a menu that appears within the virtual world.

Killobyte - The game The game takes place in many different settings, as players face a series of increasing challenges and accumulate points. In the tradition of role-playing games, players get some choice over their characters' appearance and abilities, and they must use logic and ingenuity to overcome each obstacle, often involving riddles. When encountering another character, it is not always easy to tell whether the person is a fellow player or a part of the program.

Killobyte - The game As is implied by the name (a pun on the word kilobyte), the game enables users to kill or be killed. Violence is quite graphic. Players who die receive electric shocks and the feeling of being buried in a coffin, and each death is longer and more unpleasant than the last one.

Killobyte - Plot summary
The novel cuts between Walter Toland, a former police officer, and Baal Curran, an angst-ridden teenage girl. Both are playing Killobyte from their own home, hooked to the network through a telephone modem. Walter notices Baal's name on a list and initially assumes she is a man. Indeed, each of them first poses as the other sex.

Walter is learning the game as he goes, having neglected to read the instruction manual. He narrowly survives attacks by gunslingers, snakes, and runaway vehicles. Each time he destroys an enemy, he receives a point, and a door to a new setting appears. Eventually he must solve a more complicated problem when he finds himself in a women's prison, evading execution and a possible mole (espionage)|mole.

In the meantime, Baal enters a fantasy setting in which a knight must rescue a princess from an evil sorcerer in a castle guarded by a dragon

They begin telling each other about their real lives

They discover that he may be capable of sex within the game, but they are interrupted by a hacker who has infiltrated the software. Calling himself phreaking|Phreak, the hacker targets specific individuals and locks them in the game so that he can harass them. Walter receives an error message every time he attempts to return to the real world. Aided by his police training, he remains calm and talks to Phreak, even though he knows his real body is in danger of eventual dehydration.

Baal temporarily quits the game after agreeing to meet Walter later in the game's next section, where they would use signals to identify each other, since they would have a different appearance

We learn that Phreak is a 15-year-old boy whose father was part a snake handling sect and died of a rattlesnake bite. The mother eventually died, and Phreak is convinced that she was also killed by snakes, which he believes lurk in the shadows waiting to pounce on him. He lives in his aunt's house, secretly using his own telephone line to hack into games, but he avoids experiencing the games directly for fear of being traced, despite the temptations of cybersex|online sex.

Baal reenters the game world

Walter bombs the prison, causing their virtual deaths (so that they will no longer be imprisoned when they reappear)

They all end up in a special section called Potpourri, which mixes elements of various other sections

Phreak has manipulated police records so that there is a phony arrest warrant on Walter, but the friends he met in Killobyte show up and refute the charges

Killobyte - Author's note
Anthony writes about the development of the novel and the research it required

Gigabyte M912 Other criticisms focus on Gigabyte's choice to ship one variant with Windows Vista Home Basic, which lacks official Tablet PC support.[ Gigabyte M912 Mini-Review]

Gigabyte M912 - Features and variations
Common features:[ Official specification sheet]

**Linux models, and possibly M912T:

*4-in-1 card reader: Secure Digital/MMC/Memory Stick/MS Pro †

Retrieved on Another expected model, the M912T, is believed to have DVB-T support.[ Gigabyte’s Mobile TV netbook coming soon! M912V/X now shipping

Good OS inc, has revealed that the Gigabyte M912 will be the first netbook to be offered with their Cloud (operating system)|Cloud instant on browser based operating system, that will add instant on internet access to the M912 touch screen netbook.[ cloud available on the M912]

Quiet PC - Gigabyte i-RAM
The i-RAM is a solid-state disk which has four DIMM slots to allow regular PC Random access memory|RAM to be used like a disk. It is much faster than a hard disk, does not have the write cycle limitations of flash memory, however it requires power continuously in order to maintain its contents (from standby power or a battery when the system is off), uses more power than many laptop hard drives, has maximum capacity of 4 GiB, and is expensive.

Terabyte The 'terabyte' is a multiple of the unit byte for Computer data storage|digital information. The SI prefix|prefix tera-|tera represents the fourth power of 1000, and means 1012 in the International System of Units (SI), and therefore one terabyte is one 10^12|trillion (short scale) bytes. The unit symbol for the terabyte is 'TB'.

Terabyte A related unit, the tebibyte (TiB), using a binary prefix, is the corresponding 4th power of One terabyte expressed using binary prefixes is about tebibytes, or 931 gibibytes.

Petabyte A 'petabyte' (symbol: PB) is 1015 bytes of Computer data storage|digital information.

Petabyte The SI prefix|prefix peta-|peta indicates the fifth power of 1000 and means 1015 in the International System of Units (SI), and therefore 1 petabyte is one names of large numbers|quadrillion (long and short scales|short scale) bytes, or 1 names of large numbers#Extensions of the standard dictionary numbers|billiard (long scale) bytes.

Petabyte A related unit, the pebibyte (PiB), using a binary prefix, means , which is more than 12% greater than (250 bytes = ).

Petabyte - Usage examples
Examples of the use of the petabyte to describe data sizes in different fields are:

* The world's effective capacity to exchange information through two-way telecommunication networks was 281 petabytes of (optimally compressed) information in 1986, 471 petabytes in 1993, 2,200 petabytes in 2000, and 65,000 (optimally compressed) petabytes in 2007 (this is the informational equivalent to every person exchanging 6 newspapers per day).[ The World’s Technological Capacity to Store, Communicate, and Compute Information], Martin Hilbert and Priscila López (2011), Science (journal), 332(6025), 60-65; see also [ free access to the study] and [ video animation].

* Computer hardware: Teradata Database 12 has a capacity of 50 petabytes of compressed data.

* Internet: Google processed about 24 petabytes of data per day in The BBC|BBC's BBC iPlayer|iPlayer is reported to use 7 petabytes of bandwidth each month. Imgur transfers about 4 petabytes of data per month. Yahoo stores 2 petabytes of data on behavior. Netflix uses 1 petabyte to store the videos for streaming.

* Telecoms: ATT Inc.|ATT transfers about 30 petabytes of data through its networks each day.

* Physics: The List of Large Hadron Collider experiments|experiments in the Large Hadron Collider produce about 15 petabytes of data per year, which are distributed over the Worldwide LHC Computing Grid.

* Neurology: It is estimated that the human brain's ability to store memories is equivalent to about 2.5 petabytes of binary data.

* As of April 2009, Facebook users had uploaded over 15 billion photos which made Facebook the biggest photo sharing website. For each uploaded photo, Facebook generates and stores four images of different sizes, which translated to a total of 60 billion images and 1.5 petabytes of storage, to date this will be even greater.

* Climate science: The German Climate Computing Centre (DKRZ) has a storage capacity of 60 petabytes of climate data.[ Treehugger, 11 Dec 2009: Meet the world's most powerful weather supercomputer]

* Archives: The Internet Archive contains about 10 petabytes in cultural material as of October 2012, having grown more than 190 terabytes per month since reaching 5.8 petabytes in December It was growing at the rate of about 100 terabytes per month in March 2009.

* Games: World of Warcraft uses 1.3 petabytes of storage to maintain its game. Steam (software)|Steam, a digital gaming service developed by Valve Corporation|Valve, delivers over 30 petabytes of content monthly.

*In August 2011, IBM was reported to have built the largest storage array ever, with a capacity of 120 petabytes.

*In January 2012, Cray began construction of the Blue Waters|Blue Waters Supercomputer, which will have a capacity of 500 petabytes making it the largest storage array ever if realized.

*In July 2012 it was revealed that CERN amassed about 200 petabytes of data from the more than 800 trillion collisions looking for the Higgs boson.

* At its 2012 closure of file storage services, Megaupload held ~28 petabytes of user uploaded data.

* In August 2012, Facebook's Hadoop clusters include the largest single HDFS cluster known, with more than 100 PB physical disk space in a single HDFS filesystem.

* In May 2013, Microsoft announces that as part of their migration of Hotmail accounts to the new Outlook.com system, they'd migrated over 150 Petabytes of user data in six weeks.

* One petabyte is enough to store the DNA of the entire population of the USA - with cloning it twice.

* BitTorrent Sync has transferred over 30 petabytes of data since its pre-alpha release in January

* Petabyte of average MP3 encoded (for mobile, ~ one megabyte per minute) average songs, lasting for ~4 minutes, gives album that can be fully heard after over 2000 years of playing continuously.

University of Pittsburgh Medical Center - UPMC Presbyterian Shadyside
Also operating under UPMC Presbyterian Shadyside is the UPMC Sports Performance Complex, located less than from the Oakland-based facilities on Pittsburgh's South Side (Pittsburgh)|South Side

University of Pittsburgh Medical Center - UPMC Presbyterian
The School of Medicine uses UPMC Presbyterian for research and graduate programs.[ American Hospital Directory] retrieved June 17, 2007[ UPMC Presbyterian Specialties] retrieved June 17, 2007

Mbps - Decimal multiples of bytes
'WARNING: These units are often not used in the suggested ways! See above section titled #Variations|variations.'

Mbps - Kilobyte per second
A 'kilobyte per second' – 'kBps or kB/s' – is a unit of data transfer rate equal to:

Mbps - Megabyte per second
A 'megabyte per second' – 'MBps or MB/s' – (not to be confused with Mbps or Mb/s, which would be megabits per second) is a unit of data transfer rate equal to:

Mbps - Gigabyte per second
A 'gigabyte per second' – 'GBps or GB/s' – is a unit of data transfer rate equal to:

Mbps - Terabyte per second
A 'terabyte per second' – 'TBps or TB/s' – is a unit of data transfer rate equal to:

Mbps - Kibibyte per second
A 'kibibyte per second' ('KiB/s') is a unit of data transfer rate equal to:

Mbps - Mebibyte per second
A 'mebibyte per second' ('MiB/s') is a unit of data transfer rate equal to:

Mbps - Gibibyte per second
A 'gibibyte per second' ('GiB/s') is a unit of data transfer rate equal to:

Mbps - Tebibyte per second
A 'tebibyte per second' ('TiB/s') is a unit of data transfer rate equal to:

Presbyterian Many Reformed churches are organized this way, but the word Presbyterian, when capitalized, is often applied uniquely to the churches which trace their roots to the Scottish and English churches that bore that name and English political groups that formed during the English Civil War|Civil War.

Presbyterian The Presbyterian denominations in Scotland hold to the theology of John Calvin and his immediate successors, although there is a range of theological views within contemporary Presbyterianism.

Presbyterian Local congregations of churches which use presbyterian polity are governed by session (Presbyterianism)|sessions made up of representatives of the congregation (presbyterian elder|elders); a conciliarity|conciliar approach which is found at other levels of decision-making (Presbytery (church polity)|presbytery, Presbyterian synod|synod and General Assembly (presbyterian church)|general assembly).

Presbyterian Some Presbyterian churches have entered into unions with other churches, such as Congregational church|Congregationalists, Lutherans, Anglicans, and Methodists.

Presbyterian - History
In December 1560, the First Book of Discipline was published, outlining important doctrinal issues but also establishing regulations for church government, including the creation of ten ecclesiastical districts with appointed superintendents which later became known as Presbytery (church polity)|presbyteries.

Presbyterian - History
In time, the Scots Confession would be supplanted by the Westminster Confession of Faith, and the Westminster Larger Catechism|Larger and Westminster Shorter Catechism|Shorter Catechisms, which were formulated by the Westminster Assembly between 1643 and 1649.

Presbyterian - Characteristics
Some of the splits have been due to doctrinal controversy, while some have been caused by disagreement concerning the degree to which those ordained to church office should be required to agree with the Westminster Confession of Faith, which historically serves as an important confessional document - second only to the Bible, yet directing particularities in the standardization and translation of the Bible - in Presbyterian churches.

Presbyterian - Characteristics
It is generally considered that the point of such learning is to enable one to put one's faith into practice; some Presbyterians generally exhibit their faith in action as well as words, by generosity, hospitality, and the constant pursuit of social justice and reform, as well as proclaiming the gospel of Christ.

Presbyterian - Governance
A congregation issues a call for the pastor's service, but this call must be ratified by the local presbytery.

These are sometimes known as presbyters to the full congregation.

This congregation / Presbytery (presbyterian church)|presbytery / synod / General Assembly (presbyterian church)|general assembly schema is based on the historical structure of the larger Presbyterian churches, such as the Church of Scotland or the Presbyterian Church (U.S.A.); some bodies, such as the Presbyterian Church in America and the Presbyterian Church in Ireland, skip one of the steps between congregation and General Assembly, and usually the step skipped is the Synod

Presbyterian governance is practised by Presbyterian denominations and also by many other Reformed churches.Constitution of the Presbyterian Church (USA): Part I: The Book of Confessions, p. 267.

Presbyterian - Doctrine
Presbyterianism is historically a confessional tradition

However, there has arisen a spectrum of approaches to confessionalism (religion)|confessionalism. The manner of subscription, or the degree to which the official standards establish the actual doctrine of the church, turns out to be a practical matter. That is, the decisions rendered in ordination and in the courts of the church largely determine what the church means, representing the whole, by its adherence to the doctrinal standard.

The Presbyterian Church in Canada retains the Westminster Confession of Faith in its original form, while admitting the historical period in which it was written should be understood when it is read.

Some Presbyterian Churches, such as the Free Church of Scotland (post 1900)|Free Church of Scotland, have no such conscience clause.

The Presbyterian Church (U.S.A.) has adopted the Book of Confessions, which reflects the inclusion of other Reformed confessions in addition to the Westminster Standards

The Presbyterian Church in Canada developed the confessional document Living Faith (1984) and retains it as a subordinate standard of the denomination. It is confessional in format, yet like the Westminster Confession, draws attention back to original Bible text.

Presbyterians in Ireland who rejected Calvinism and the Westminster Confessions formed the Non-subscribing Presbyterian Church of Ireland.

Presbyterian - Worship
It was enacted as law by the Scottish Parliament, and became one of the foundational documents of Presbyterian church legislation elsewhere.

Historically, the driving principle in the development of the standards of Presbyterian worship is the Regulative principle of worship, which specifies that (in worship), what is not commanded is forbidden.Westminster Confession of Faith, Chapter XXI, paragraph I

Other Presbyterians, however, such as the Reformed Presbyterian churches|Reformed Presbyterians, would practice a capella exclusive psalmody, as well as eschew the celebration of holy days.

Among the Paleo-orthodoxy|paleo-orthodox and emerging church movements in Protestant and evangelical churches, in which some Presbyterians are involved, clergy are moving away from the traditional black Geneva gown to such vestments as the alb and chasuble, but also cassock and surplice (typically a full length Old English style surplice which resembles the Celts|Celtic alb, an ungirdled liturgical tunic of the old Gallican Rite), which some, particularly those identifying, with the Liturgical Renewal Movement, hold to be more ancient and representative of a more ecumenical past.

Presbyterian - Sacraments
* Baptism, in which they would Infant baptism|baptize infants, as well as unbaptized adults by the Aspersion (sprinkling) or Affusion (pouring) method, rather than the Baptism#Immersion|Immersion method.

* The Eucharist|Lord's Supper (also known as Communion), in which they would believe that Christ is present in the bread and wine through the Holy Spirit, as opposed to being locally present.

Unlike many denominations that baptize infants on the basis of baptismal regeneration, Presbyterians, along with their Continental Reformed counterparts, baptize infants on the belief that as Hebrew infants were circumcised in order to show that they were part of the covenant community, infants of believing parents are likewise to be baptized.

Presbyterian - Architecture
Early Presbyterian meeting-houses were extremely plain

Prosperous congregations built imposing churches, such as Fourth Presbyterian Church of Chicago|Fourth Presbyterian in Chicago, Madison Avenue Presbyterian and Fifth Avenue Presbyterian Church|Fifth Avenue Presbyterian in New York City, Shadyside Presbyterian Church in Pittsburgh, PA, East Liberty Presbyterian Church in Pittsburgh, PA, First Presbyterian Church (Dallas, Texas)|First Presbyterian in Dallas, House of Hope Presbyterian Church in Saint Paul, Minnesota and many others.

Presbyterian architecture generally makes significant use of symbolism.

Presbyterian - France There is a Church of Scotland (Presbyterian) in central Paris The Scots Kirk, Paris which is English-speaking, and is attended by many nationalities. It maintains close links with the Church of Scotland in Scotland itself, as well as with the Reformed Church of France.

Presbyterian - Scotland
The Church was eventually organised by Andrew Melville along Presbyterian lines to become the national Church of Scotland

Further splits took place, especially over theological issues, but most Presbyterians in Scotland were reunited by 1929 union of the established Church of Scotland and the United Free Church of Scotland.

The Presbyterian denominations in Scotland today are the Church of Scotland, the Free Church of Scotland (post 1900)|Free Church of Scotland, the United Free Church of Scotland, the Free Church of Scotland (Continuing), the Free Presbyterian Church of Scotland, the Associated Presbyterian Church (Associated Presbyterian Churches), and the Reformed Presbyterian Church of Scotland.

Within Scotland the term kirk is usually used to refer to a local Presbyterian church. Informally the term 'The Kirk' refers to the

Presbyterian - England
By the 18th century many English Presbyterian congregations had become Unitarianism|Unitarian in doctrine.

There is also a congregation in the heart of London's financial district called [ London City Presbyterian Church] that is also affiliated with Free Church of Scotland.

Two former Presbyterian congregations, St Columba's, Cambridge (founded in 1879), and St Columba's, Oxford (founded as a chaplaincy by the PCofE and the Church of Scotland in 1908 and as a congregation of the PCofE in 1929), continue as congregations of the URC and university chaplaincies of the Church of Scotland.

In recent years a number of smaller denominations adopting Presbyterian forms of church government have organised in England, including the International Presbyterian Church planted by evangelical theologian Francis Schaeffer of L'Abri|L'Abri Fellowship in the 1970s, and the Evangelical Presbyterian Church in England and Wales founded in the North of England in the late 1980s.

Presbyterian - Wales In Wales Presbyterianism is represented by the Presbyterian Church of Wales, which was originally composed largely of Calvinistic Methodists who accepted Calvinist theology rather than the Arminianism of the Wesleyan Methodists. They broke off from the Church of England in 1811, ordaining their own ministers. They were originally known as the Calvinist Methodist connexion and in the 1920s it became alternatively known as the Presbyterian Church of Wales.

Presbyterian - Ireland
Presbyterianism is represented in Ireland by the Presbyterian Church in Ireland, the Free Presbyterian Church of Ulster, the Non-subscribing Presbyterian Church of Ireland, the Reformed Presbyterian Church of Ireland and the Evangelical Presbyterian Church (Ireland)|Evangelical Presbyterian Church.

Further information: Waldensian
Presbyterian - Italy Further information: Waldensian

Presbyterian - Italy The Waldensian Evangelical Church (Chiesa Evangelica Valdese, CEV) is an Italian Protestant denomination.

Presbyterian - Italy The church was founded in the 12th century, and centuries later, after the Protestant Reformation, it adhered to Calvinist theology and became the Italian branch of the Presbyterian churches.As such, the church is a member of the World Communion of Reformed Churches.

Presbyterian - North America
Even before Presbyterianism spread with immigrants abroad from Scotland, there were divisions in the larger Presbyterian family. Some later rejoined only to separate again. In what some interpret as rueful self-reproach, some Presbyterians refer to the divided Presbyterian churches as the Split P's.

Presbyterian - United States
The nation's largest Presbyterian denomination, the Presbyterian Church (U.S.A.) – PC (USA) – can trace their heritage back to the original PCUSA, as can the Presbyterian Church in America (PCA), the Orthodox Presbyterian Church (OPC), the Bible Presbyterian Church (BPC), the Cumberland Presbyterian Church (CPC), the Cumberland Presbyterian Church in America the Evangelical Presbyterian Church (United States)|Evangelical Presbyterian Church (EPC) and the Evangelical Covenant Order of Presbyterians (ECO).

Other Presbyterian bodies in the United States include the Reformed Presbyterian Church of North America (RPCNA), the Associate Reformed Presbyterian Church (ARP), the Reformed Presbyterian Church in the United States (RPCUS), the Reformed Presbyterian Church General Assembly, the Reformed Presbyterian Church – Hanover Presbytery, the Covenant Presbyterian Church, the Presbyterian Reformed Church (North America)|Presbyterian Reformed Church, the Westminster Presbyterian Church in the United States, the Korean American Presbyterian Church, and the Free Presbyterian Church of North America.

The territory within about a radius of Charlotte, North Carolina, is historically the greatest concentration of Presbyterianism in the Southern United States, while an almost identical geographic area around Pittsburgh, Pennsylvania, contains probably the largest number of Presbyterians in the entire nation.

The PC (USA), beginning with its predecessor bodies, has, in common with other so-called mainline Protestant denominations, experienced a significant decline in members in recent years. Some estimates have placed that loss at nearly half in the last forty years..

Presbyterian influence, especially through Princeton theology can be traced in modern Evangelicalism. Balmer says that:

Evangelicalism picked up the peculiar characteristics from each strain – warmhearted spirituality from the Pietists (for instance), doctrinal precisionism from the Presbyterians, and individualistic introspection from the Puritans – even as the North American context itself has profoundly shaped the various manifestations of evangelicalism: fundamentalism, neo-evangelicalism, the holiness movement, Pentecostalism, the charismatic movement, and various forms of African-American and Hispanic evangelicalism.

However, there are still stalwart Presbyterians and Presbyterian churches in the area.

Presbyterian - Canada A sizable minority of Canadian Presbyterians, primarily in southern Ontario but also throughout the entire nation, withdrew, and reconstituted themselves as a non-concurring continuing Presbyterian body

Presbyterian - Mexico The Independent Presbyterian Church and the Presbyterian Reformed Church in Mexico, the National Conservative Presbyterian Church in Mexico are existing churches in the Reformed tradition.

There are also ethnic Korean Presbyterian churches in the country
Presbyterian - Brazil There are also ethnic Korean Presbyterian churches in the country

Presbyterian - Brazil Congregational churches present in the country are also part of the Calvinistic tradition in Latin America.

Presbyterian - Other Latin American states
There are probably more than four million members of Presbyterian churches in all of Latin America. Presbyterian churches are also present in Peru, Bolivia, Cuba, Trinidad and Tobago, Venezuela, Colombia, Chile, Paraguay, Costa Rica, Nicaragua, Argentina and others, but with few members. The Presbyterian Church in Belize has 14 churches and church plants and there is a Reformed Seminary founded in Some Latin Americans in North America are active in the Presbyterian Cursillo Movement.

Presbyterian - Africa Presbyterianism arrived in Africa in the 19th century through the work of Scottish missionaries and founded churches such as St Michael and All Angels Church, Blantyre, Malawi. The church has grown extensively and now has a presence in at least 23 countries in the region.

Presbyterian - Africa The Presbyterian Church of Nigeria, western Africa is also healthy and strong in mostly the southern states of this nation, strong density in the south-eastern states of this country

Presbyterian - Kenya The Presbyterian Church of East Africa, based in Kenya, is particularly strong, with 500 clergy and 4 million members.

Presbyterian - Malawi In Malawi there is the Reformed Presbyterian Church in Malawi has 150 congregations and 17 000–20 000 members. It was a mission of the Free Presbyterian church of Scotland. The Restored Reformed Church works with RPCM. Evangelical Presbyterian Church in Malawi is an existing small church.

Presbyterian - Southern Africa
Southern Africa is a major base of Reformed and Presbyterian Churches.

Presbyterian - Northern Africa
In addition also there are a number of Presbyterian Churches in north Africa, the most known is the Nile Synod in Egypt and a recently founded synod for Sudan.

Presbyterian - South Korea
Presbyterian Churches are the biggest and by far the most influential Protestant denominations in South Korea, with close to 20,000 churches affiliated with the two largest Presbyterian denominations in the country.. In South Korea there are 15 million Protestants and about are Presbyterians. In South Korea there are 100 different Presbyterian denominations..

Another notable Presbyterian denomination in Korea is 한국기독교장로회 (The Presbyterian church in the Republic of Korea or PROK), which is one of the staunchest members of the World Council of Churches

Korean Presbyterian denominations are active in evangelism and many of its missionaries are being sent overseas, being the second biggest missionary sender in the world after the United States. GSM, the missionary body of the Hapdong General Assembly of Presbyterian Churches of Korea, is the single largest Presbyterian missionary organization in the Korea..

In Oryu-dong, Pyungkang Cheil is one of the largest Christian churches in South Korea. Another congregation in Seoul, Myungsung Presbyterian Church, claims to be the largest Presbyterian Church in the world. In addition there are many Korean-American Presbyterians in the United States, either with their own church sites or sharing space in pre-existing churches as is the case in Australia, New Zealand and even Muslim countries such as Saudi Arabia with Korean immigration.

Presbyterian - Taiwan Former Republic of China|ROC president Lee Teng-hui (in office ) is a Presbyterian.

Presbyterian - India Presbyterians participated in the mergers that resulted in the Church of North India and the Church of South India.

Presbyterian - Australia
For example, although the Presbyterian Church of Australia reinstated the ban on the ordination of women to the ministry in 1991, one of the two women ordained prior to that date has kept her position in the denomination and is currently the Senior Minister of St Andrew's Presbyterian Church in Canberra.

Presbyterian - New Zealand
In New Zealand, Presbyterian is the dominant denomination in Otago and Southland due largely to the rich Scottish people|Scottish and to a lesser extent Ulster-Scots heritage in the region. The area around Christchurch, Canterbury, is dominated philosophically by the Anglican (Episcopalian) denomination.

Presbyterian - New Zealand
Originally there were two branches of Presbyterianism in New Zealand, the northern Presbyterian church which existed in the North Island and the parts of the South Island north of the Waitaki River, and the Synod of Otago and Southland, founded by Free Church of Scotland (1843–1900)|Free Church settlers in southern South Island. The two churches merged in 1901, forming what is now the Presbyterian Church of Aotearoa New Zealand.

Presbyterian - Vanuatu
Vanuatu is the only country in the South Pacific with a significant Presbyterian heritage and membership

* an unexpected continuation byte

* a start byte not followed by enough continuation bytes

* A 4-byte sequence (starting with 0xF4) that decodes to a value greater than U+10FFFF

RFC 3629 states Implementations of the decoding algorithm MUST protect against decoding invalid sequences. The Unicode Standard requires decoders to ...treat any ill-formed code unit sequence as an error condition. This guarantees that it will neither interpret nor emit an ill-formed code unit sequence.

Many UTF-8 decoders throw exceptions on encountering errors.[ decode() method of Java UTF8 object] This can turn what would otherwise be harmless errors (producing a message such as no such file) into a denial of service bug

* The invalid Unicode code points U+DC80..U+DCFF where the low 8 bits are the byte's value.

* The Unicode code points U U+00FF with the same value as the byte, thus interpreting the bytes according to ISO/IEC |ISO

* The Unicode code point for the character represented by the byte in Windows-1252|CP1252. This is similar to using ISO , except that some characters in the range 0x80..0x9F are mapped into different Unicode code points. For example, 0x80 becomes the Euro sign, U+20AC.

These replacement algorithms are lossy: an invalid string is converted to the same sequence of code points that a valid UTF-8 string could have.

Many programs are specified to allow input in one of several encodings, for example UTF-8, UTF-16 or ISO In that case, the software would first check for UTF-8 correctness. If incorrect then it would check if it is UTF-16, and if not interpret it as entirely ISO

UTF-8 - Byte order mark Software that is not aware of multibyte encodings will display the BOM as three strange characters (e.g

UTF-8 - Byte order mark * Programming language parsers not explicitly designed for UTF-8 can often handle UTF-8 in string constants and comments, but cannot parse the BOM at the start of the file.

UTF-8 - Byte order mark * Programs that identify file types by leading characters may fail to identify the file if a BOM is present even if the user of the file could skip the BOM. An example is the Unix Shebang (Unix)|shebang syntax. Another example is Internet Explorer which will render pages in standards mode only when it starts with a document type declaration.

UTF-8 - Byte order mark * Programs that insert information at the start of a file will break use of the BOM to identify UTF-8 (one example is offline browsers that add the originating URL to the start of the file).

Exabytes The 'exabyte' is a multiple of the unit byte for Computer data storage|digital information. The SI prefix|prefix exa-|exa indicates the sixth power of 1,000 and means 1018 in the International System of Units (SI), and therefore 1 exabyte is one quintillion bytes (Long and short scales|short scale). The unit symbol for the exabyte is 'EB'.

Exabytes - Usage examples
* In principle, the 64-bit microprocessors found in many computers can address space|address 16 exabytes of memory.

* The world's technological capacity to store information grew from 2.6 (optimally compressed) exabytes in 1986 to 15.8 in 1993, over 54.5 in 2000, and to 295 (optimally compressed) exabytes in 2007

* The world’s technological capacity to receive information through one-way broadcast networks was 432 exabytes of (optimally compressed) information in 1986, 715 (optimally compressed) exabytes in 1993, 1,200 (optimally compressed) exabytes in 2000, and 1,900 in 2007.

* The world's effective capacity to exchange information through two-way telecommunication networks was exabytes of (optimally compressed) information in 1986, in 1993, 2.2 in 2000, and 65 (optimally compressed) exabytes in 2007.

* In 2004, the global monthly Internet traffic passed 1 exabyte for the first time. In January 2007, Bret Swanson of the Discovery Institute coined the term exaflood for a supposedly impending flood of exabytes that would cause the Internet's congestive collapse. Nevertheless, the global Internet traffic has continued its exponential growth, undisturbed, and it is estimated at 21 exabytes per month.[ Cisco Systems]

* According to the June 2009 Cisco Visual Networking Index Internet traffic|IP traffic forecast, global mobile data traffic will grow at a CAGR of 131 percent between 2008 and 2013, reaching over two exabytes per month by 2013.[ Cisco Visual Networking Index (Cisco VNI)]

* According to the 2011 update of Cisco's VNI IP traffic forecast, by 2015, annual global IP traffic will reach 966 exabytes or nearly one full zettabyte. Internet video will account for 61% of total Internet data.

By 2017 global mobile data traffic will reach 11.2 exabytes per month (134 exabytes annually); growing 13-fold from 2012 to 2017.[ Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2012–2017][ The Zettabyte Era - Visual Networking Index (VNI) - Cisco Systems]

* The global data volume at the end of 2009 had reached 800 exabytes.[ Global data volume 2009 reached 800 exabyte], genevaassociation.org, May Retrieved

* According to an International Data Corporation|IDC paper sponsored by EMC Corporation, 161 exabytes of data were created in 2006, 3 million times the amount of information contained in all the books ever written, with the number expected to hit 988 exabytes in 2010.

According to IBM, the new SKA telescope initiative will generate over an exabyte of data every day

* According to the Digital Britain Report, 494 exabytes of data was transferred across the globe on June 15, 2009.[

* The ext4 file system format supports volumes up to 1 exabyte in size, although the userspace tools cannot yet administer such filesystems.

* Oracle Corporation claimed the first exabyte tape library with the SL8500 and the T10000C tape drive in January 2011.[

Exabytes - All words ever spoken
Mark Liberman calculated the storage requirements for all human speech at 42 zettabytes (42,000 exabytes, and 8,400 times the original estimate), if digitized as 16kHz 16-bit audio, although he did freely confess that maybe the authors [of the exabyte estimate] were thinking about text.

Exabytes - All words ever spoken
Research from University of Southern California estimates that the amount of data stored in the world by 2007 was 295 exabytes and the amount of information shared on two-way communications technology, such as cell phones in 2007 as 65 exabytes.

Exabytes - 100,000 Libraries of Congress
The Library of Congress is commonly estimated at 10 terabytes for all printed material. Recent estimates of the size including audio, video, and digital materials is from 3 petabytes to 20 petabytes.

Nibble - Extracting a nibble from a byte
In the C programming language:

Nibble - Extracting a nibble from a byte
#define HI_NIBBLE(b) (((b) /sourcesource lang=lisp/source

AES-128 - The SubBytes step
In the SubBytes step, each byte a_ in the state matrix is replaced with a SubByte S(a_) using an 8-bit substitution box, the Rijndael S-box

AES-128 - The SubBytes step
While performing the decryption, Inverse SubBytes step is used, which requires first taking the affine transformation and then finding the multiplicative inverse( just reversing the steps used in SubBytes step).

TIFF - Byte order The next two-byte word represents the number 42 (number)|42 which happens to be the ASCII character *, also represented by hexadecimal 2A, selected because of its binary pattern (101010) and Answer to the Ultimate Question of Life, the Universe and Everything|for its deep philosophical significance.

TIFF - Byte order All words, double words, etc., in the TIFF file are assumed to be in the indicated byte order. The TIFF 6.0 specification states that compliant TIFF readers must support both byte orders (II and MM); writers may use either.

Lookup - Counting '1' bits in a series of bytes
One discrete problem that is expensive to solve on many computers, is that of counting the number of bits which are set to 1 in a (binary) number, sometimes called the Hamming weight|population function. For example, the decimal number 37 is in binary, so it contains three bits that are set to binary 1.

A simple example of C (programming language)|C code, designed to count the 1 bits in a int, might look like this:

This apparently simple algorithm can take potentially hundreds of cycles even on a modern architecture, because it makes many branches in the loop - and branching is slow. This can be ameliorated using loop unrolling and some other compiler optimizations. There is however a simple and much faster algorithmic solution - using a trivial hash function table lookup.

Simply construct a static table, bits_set, with 256 entries giving the number of one bits set in each possible byte value (e.g. 0x00 = 0, 0x01 = 1, 0x02 = 1, and so on). Then use this table to find the number of ones in each byte of the integer using a trivial hash function lookup on each byte in turn, and sum them. This requires no branches, and just four indexed memory accesses, considerably faster than the earlier code.

/* (this code assumes that 'int' is 32-bits wide) */

Storage caches (including disk caches for files, or processor caches for either code or data) work also like a lookup table. The table is built with very fast memory instead of being stored on slower external memory, and maintains two pieces of data for a subrange of bits composing an external memory (or disk) address (notably the lowest bits of any possible external address):

* one piece (the tag) contains the value of the remaining bits of the address; if these bits match with those from the memory address to read or write, then the other piece contains the cached value for this address.

A single (fast) lookup is performed to read the tag in the lookup table at the index specified by the lowest bits of the desired external storage address, and to determine if the memory address is hit by the cache. When a hit is found, no access to external memory is needed (except for write operations, where the cached value may need to be updated asynchronously to the slower memory after some time, or if the position in the cache must be replaced to cache another address).

Highway Addressable Remote Transducer Protocol - Number of data bytes
Specifies the number of communication data bytes to follow.

University of Sunderland - SportsByte
In spring 2012 SportsByte gained national praise, making the final shortlist for the National Union of Students National Student Journalism Awards 'Best Student Media' award.

University of Sunderland - SportsByte
The University of Sunderland’s Institute of Sport launched SportsByte in 2011 after months of planning and development with the Faculty of Art, Design, and Media’s lead academic Journalism staff

Joseph Smith (Presbyterian minister, born 1736)
'Joseph Smith' (1736–1792) was a prominent Presbyterian minister in Western Pennsylvania. He is one of the founders of Washington Jefferson College.

Smith was born in Cecil County, Maryland, not far from the modern location of the Conowingo Dam. He graduated from the Princeton University|College of New Jersey (now Princeton University) in 1764 at the relatively mature age of 28. He was tall, blond, slender, and had piercing eyes and was emotional to a degree we do not usually associate with Englishmen.

He was first licensed to preach by New Castle, Pennsylvania|New Castle Presbytery and accepted a call in Chester County, Pennsylvania|Brandywine, Pennsylvania. He and his family moved west to Cross Creek in what is now Washington County, Pennsylvania. There, he built a home and a log school called The Study, where he taught.

Smith was known as a firery and eloquent speaker and held days-long revivals on the high plateau at Upper Buffalo. He loved reading religious materials in the original language: The Old Testament in Hebrew language|Hebrew, the New Testament in Koine Greek|Greek, Edward Leigh (writer)|Edward Leigh's Critica Sacra, and Pool's Synopsis. It was said that he kept a cloak at the foot of his bed for use when he would spontaneously rise to pray in his bitterly cold room in the middle of the night.

First Presbyterian Church (Washington, Pennsylvania)
The 'First Presbyterian Church 1793', alternatively known as the 'First Presbyterian Church', is a Presbyterian church in Washington, Pennsylvania. It has been the de facto college church for Washington Jefferson College since the early 19th century. It's under the Washington Presbytery.

First Presbyterian Church (Washington, Pennsylvania) - History
It was founded in 1793 under the auspices of the Presbytery of Redstone. Matthew Brown (college president)|Matthew Brown, who was List of Presidents of Washington Jefferson College|President of Washington Jefferson College|Washington Academy at the time, was the first pastor. The congregation first met in the McMillan Hall|stone academy building of the Washington Jefferson College|Washington Academy.

Then, the congregation worshipped at the Washington County Courthouse (Pennsylvania)|second courthouse, where the pastor would stand in the Bench (law)|judge's bench and preach to the congregation

A second building, in the Greek Revival Architecture style, was built in It had severe structural flaws and was demolished in 1868.

First Presbyterian Church (Washington, Pennsylvania) - Ministry
The church operates the Matthew Brown Fellowship, a faith-based program that selects several Washington Jefferson College students with local charitable organizations. In addition to the charity work, Matthew Brown Fellows work attend monthly study groups with other Fellows. The program encompasses the Matthew Brown Music Scholars program, which selects two student-musicians to practice and perform with the First Presbyterian Church's choir.

Church of the Covenant (Pennsylvania) - Second Presbyterian Church
The Second Presbyterian Church leased a church building from a Methodist Protestant building on Beau Street

The congregation stayed in that building for 14 years before beginning a construction project in 1884, with a fund of $25,000. The new building at 65 East Beau Street was dedicated on March 6, 1887, with Hays returning to give the sermon. The building featured a Johnson Pipe Organ and a 450-seat auditorium with a groined ceiling and bowled floor and an adjacent lecture room.

The church outgrew that building by 1929 and constructed a new Gothic Revival architecture|Gothic Revival style building on East Beau Street, the building that now houses the Church of the Covenant.

Judge John Addison McIvaine was a prominent church member. The church was home to three important revivals in its history.

The church had a historically strong tie with the college, as a number of its men attended Wednesday evening prayer meetings and 75 to 100 attending Sunday service. Many of these students eventually joined the ministry or became missionaries.

Church of the Covenant (Pennsylvania) - Third Presbyterian Church and merger
In 1959, the Third Presbyterian Church's efforts to construct a new building were frustrated, which necessitated its merger with the Second Presbyterian Church

Java Card - Bytecode Techniques exist for overcoming the size limitations, such as dividing the application's code into packages below the 64kibibyte|KiB limit.

Zettabytes The 'zettabyte' is a multiple of the unit byte for Computer data storage|digital information. The SI prefix|prefix zetta-|zetta indicates the seventh power of 1000 and means 1021 in the International System of Units (SI), and therefore one zettabyte is one sextillion (one long and short scales|long scale trilliard) bytes. The unit symbol is 'ZB'.

Zettabytes - Usage examples
* GUID Partition Table (GPT) allows for a maximum disk and partition size of 9.4 zettabytes, or 8 zebibytes, when using 512-byte Disk sector|sectors.

Zettabytes - Usage examples
* ZFS allows for a maximum storage capacity of 256 quadrillion zettabytes.

Zettabytes - Comparisons for scale
The combined space of all computer hard drives in the world was estimated at approximately 160 exabytes in As of 2009, the entire World Wide Web was estimated to contain close to 500 exabytes. This is one half zettabyte. This has increased rapidly however, as Seagate Technology reported selling 330 exabytes worth of hard drives during the 2011 Fiscal Year.

* The world's technological capacity to receive information through one-way broadcast networks was zettabytes of (optimally compressed) information in 1986, in 1993, 1.2 in 2000, and 1.9 (optimally compressed) zettabytes in 2007 (this is the informational equivalent to every person on earth receiving 174 newspapers per day). Vol. 332 no pp

* According to International Data Corporation, the total amount of global data is expected to grow to 2.7 zettabytes during This is an increase of 48% from 2011.

* Mark Liberman calculated the storage requirements for all human speech ever spoken at 42 zettabytes if digitized as 16kHz 16-bit audio. This was done in response to a popular expression that states all words ever spoken by human beings could be stored in approximately 5 exabytes of data (see exabyte for details). Liberman did freely confess that maybe the authors [of the exabyte estimate] were thinking about text.

* Research from the University of Southern California reports that in 2007, humankind successfully sent 1.9 zettabytes of information through broadcast technology such as televisions and GPS.

* Research from the University of California, San Diego reports that in 2008, Americans consumed 3.6 zettabytes of information.

Subsequent reports have downgraded this to between 3 and 12 exabytes.[ Blueprints Of NSA's Ridiculously Expensive Data Center In Utah Suggest It Holds Less Info Than Thought], Forbes, July 24, 2013, Retrieved December 19, 2013Randall Munroe

Kilobyte Retrieved on [ definition of kilobyte from Oxford Dictionaries Online]

Kilobyte For example, when referring to Data rate units|data transfer rates[ Conversion of Data Transfer Rate Units] and to disk storage space,1977 Disk/Trend Report Rigid Disk Drives, published June 1977 kilobyte means 1000 (103) bytes. On the other hand, random-access memory capacity such as CPU cache measurements are always stated in multiples of 1024 (210) bytes, due to memory's binary addressing (see Binary prefix and JEDEC memory standards).

Kilobyte The standards-based symbol for the kilobyte is 'kB', expressing 1000 bytes. The binary representation of 1024 bytes typically uses the symbol 'KB', using an upper-case K. Informally sometimes the B is dropped, then 'K', has generally been understood as 1024 bytes. However, this usage is not standardized and may be found used arbitrarily. All existing recommendations prefer to use the uppercase letter B for byte, because b is used for the bit.

Nevertheless, the term kilobyte continues to be widely used with both of the following two meanings:

* 1kB = = 103 bytes is the definition recommended by the International Electrotechnical Commission (IEC).[ Prefixes for Binary Multiples] — The NIST Reference on Constants, Units, and Uncertainty This definition is used in computer network|networking contexts and most storage media, particularly hard drives, Flash memory|Flash-based storage,[ SanDisk USB Flash Drive] Note: 1 megabyte (MB) = 1 million bytes; 1 gigabyte (GB) = 1 billion bytes

* 1KB (or kibibyte|KiB) = = 210 bytes is the definition used by most vendors of memory devices and software when referring to amounts of computer memory, such as Microsoft Windows and Linux. In the unambiguous IEC standard the unit for this amount of information is one kibibyte (KiB).

Kilobyte - Examples * The HP 2100|HP 21MX real-time computer (1974) denoted 196,608 (which is 192×1024) as 196K, while the HP 3000 business computer (1973) denoted 131,072 (which is 128×1024) as 128K.

Kilobyte - Examples * The Shugart Associates|Shugart SA inch floppy disk (1976) held 109,375 bytes unformatted, and was advertised as 110 Kbyte, using the 1000 convention. Likewise, the 8-inch Digital Equipment Corporation|DEC RX01 floppy (1975) held 256,256 bytes formatted, and was advertised as 256k. On the other hand, the Tandon Corporation|Tandon 5-inch double density|DD floppy format (1978) held 368,640 (which is 360×1024) bytes, but was advertised as 360 KB, following the 1024 convention.

Kilobyte - Examples * On modern systems, Microsoft Windows 7 would divide by 1024 and represent this as 64 KB. while Mac OS X Snow Leopard represents a 65,536 byte file as 66 KB, rounding to the nearest 1000,

Kilobyte - Examples In December 1998, the International Electrotechnical Commission|IEC addressed such multiple usages and definitions by creating unique binary prefixes to denote multiples of 1024, such as “kibibyte (KiB)”, which represents 210, or 1024, bytes. In December 1998 the International Electrotechnical Commission (IEC) [...] approved as an IEC International Standard names and symbols for prefixes for binary multiples for use in the fields of data processing and data transmission.

This incorrect result provides a hint to perform byte-swapping for the remaining values

When the byte order is specified explicitly this way, a BOM is specifically not supposed to be prepended to the text, and a U+FEFF at the beginning should be handled as a ZWNBSP character

For Internet protocols, Internet Assigned Numbers Authority|IANA has approved UTF-16, UTF-16BE, and UTF-16LE as the names for these encodings. (The names are case insensitive.) The aliases 'UTF_16' or 'UTF16' may be meaningful in some programming languages or software applications, but they are not standard names in Internet protocols.

Java bytecode Each bytecode opcode is one byte in length, although some require parameters, resulting in some multi-byte instructions

Java bytecode - Relation to Java
However, as suggested in the IBM developerWorks journal, Understanding bytecode and what bytecode is likely to be generated by a Java compiler helps the Java programmer in the same way that knowledge of assembly Language|assembly helps the C (programming language)|C or C++ programmer.[ Understanding bytecode makes you a better programmer]

Java bytecode - Instructions
:See also: Java bytecode instruction listings

As each byte has 256 potential values, there are 256 possible opcodes. Of these, 0x00 through 0xca, 0xfe, and 0xff are assigned values. 0xca is reserved as a breakpoint instruction for Java debuggers and its type is not used by the language. Similarly, 0xfe and 0xff are not used by the language and are reserved for internal use by the Java virtual machine.

Instructions fall into a number of broad groups:

* Object creation and manipulation (new, putfield)

* Method invocation and return (e.g. invokespecial, areturn)

There are also a few instructions for a number of more specialized tasks such as exception throwing, synchronization, etc.

Many instructions have prefixes and/or suffixes referring to the types of operands they operate on. These are as follows:

For example, iadd will add two integers, while dadd will add two doubles. The const, load, and store instructions may also take a suffix of the form _n, where n is a number from 0–3 for load and store. The maximum n for const differs by type.

The const instructions push a value of the specified type onto the stack

Java bytecode - Model of computation
The model of computation of Java bytecode is that of a stack-oriented programming language. For example, Assembly language|assembly code for an x86|x86 processor might look like this:

This code would add two values and move the result to a different location. Similar disassembled bytecode might look like this:

Here, the two values to be added are pushed onto the stack, where they are retrieved by the addition instruction, summed, and the result placed back on the stack. The storage instruction then moves the top value of the stack into a variable location. The numbers in front of the instructions simply represent the offset of each instruction from the beginning of the method.

This stack-oriented model extends to the object oriented aspects of the language as well. A method call called getName(), for example, may look like the following:

// This instruction pops an object from the top of the stack, retrieves the specified

// field from it, and pushes the field onto the stack.

Java bytecode - Example
31: getstatic #84; // Field java/lang/System.out:Ljava/io/PrintStream;

Java bytecode - Example
35: invokevirtual #85; // Method java/io/PrintStream.println:(I)V

Java bytecode - Generation
The most common language targeting Java Virtual Machine by producing Java bytecode is Java. Originally only one compiler existed, the javac compiler from Sun Microsystems, which compiles Java source code to Java bytecode; but because all the specifications for Java bytecode are now available, other parties have supplied compilers that produce Java bytecode. Examples of other compilers include:

* GNU Compiler for Java|GCJ, the GNU Compiler for Java, compiles from Java to Java bytecode; it is also able to compile to native machine code and is available as part of the GNU Compiler Collection (GCC).

Some projects provide Java assemblers to enable writing Java bytecode by hand. Assembly code may be also generated by machine, for example by compiler targeting Java virtual machine. Notable Java assemblers include:

* Jasmin (Java assembler)|Jasmin, takes textual descriptions for Java classes, written in a simple assembly-like syntax using Java Virtual Machine instruction set and generates a Java class file [ Jasmin Home Page]

* Jamaica (Java assembler)|Jamaica, a Macro (computer science)|macro assembly language for the Java virtual machine. Java syntax is used for class or interface definition. Method bodies are specified using bytecode instructions.[ Jamaica: The Java Virtual Machine (JVM) Macro Assembler]

Others have developed compilers, for different programming languages, in order to target the Java virtual machine, such as:

* JRuby and Jython, two scripting languages based on Ruby (programming language)|Ruby and Python (programming language)|Python

* Groovy (programming language)|Groovy, a scripting language based on Java

* Scala (programming language)|Scala, a type-safe general-purpose programming language supporting object-oriented and functional programming

* JGNAT and AdaMagic|AppletMagic, compile from the Ada programming language to Java bytecode

* Java Virtual Machine#C to bytecode compilers|C to Java byte-code compilers

* Clojure, a functional, immutable, general-purpose programming language in the LISP family with a strong emphasis on concurrency

Java bytecode - Execution
There are several virtual machines available today, both free and commercial products.

Java bytecode - Execution
If executing Java bytecode in a Java virtual machine is not desirable, a developer can also compile Java source code or Java bytecode directly to native machine code with tools such as the GCJ|GNU Compiler for Java. Some processors can execute Java bytecode natively. Such processors are known as Java processors.

Java bytecode - Support for dynamic languages
The Java Virtual Machine provides some support for Type system#Dynamic_typing|dynamically typed languages. Most of the existing JVM instruction set is Type system#Static typing|statically typed - in the sense that method calls have their signatures type-checked at compile time, without a mechanism to defer this decision to Run time (program lifecycle phase)|run time, or to choose the method dispatch by an alternative approach.

Java bytecode - Support for dynamic languages
Java Community Process|JSR 292 (Supporting Dynamically Typed Languages on the Javatrade; Platform)[ see JSR 292] added a new invokedynamic instruction at the JVM level, to allow method invocation relying on dynamic Type system#Type checking|type checking (instead of the existing statically type-checked invokevirtual instruction)

MD5 - bytes[1] (uint8_t) (val 29
// break chunk into sixteen 32-bit words w[j], 0 ≤ j ≤ 15

// Initialize hash value for this chunk:

The message to hash is passed via the first argument of the command line.

Reliable byte stream A 'reliable byte stream' is a common service paradigm in computer networking; it refers to a byte stream in which the bytes which emerge from the communication channel at the recipient are exactly the same, and in exactly the same order, as they were when the sender inserted them into the channel.

Reliable byte stream The classic example of a reliable byte stream communication protocol is the Transmission Control Protocol, one of the major building blocks of the Internet.

Reliable byte stream A reliable byte stream is not the only reliable service paradigm which computer network communication protocols provide, however; other protocols (e.g. SCTP) provide a reliable message stream, i.e. the data is divided up into distinct units, which are provided to the consumer of the data as discrete objects.

Reliable byte stream - Mechanism
Communication protocols which implement reliable byte streams, generally over some unreliable lower level, use a number of mechanisms to provide that reliability. ARQ protocols have an important role for achieving reliability.

Reliable byte stream - Mechanism
All data items are identified with a sequence number, which is used both to make sure that the data are delivered to the entity at the other end in the correct order, and to check for lost data items

Web2py - Bytecode distribution
Web2py can compile web applications for distribution in bytecode compiled form, without source code. Unlike frameworks that use specialized template languages for their views, Web2py can also compile the view code into bytecode, since it is pure Python code.

Java Virtual Machine - Bytecode verifier
A basic philosophy of Java is that it is inherently safe from the standpoint that no user program can crash the host machine or otherwise interfere inappropriately with other operations on the host machine, and that it is possible to protect certain methods and data structures belonging to trusted code from access or corruption by untrusted code executing within the same JVM

The JVM verifies all bytecode before it is executed. This verification consists primarily of three types of checks:

The first two of these checks take place primarily during the verification step that occurs when a class is loaded and made eligible for use. The third is primarily performed dynamically, when data items or methods of a class are first accessed by another class.

The verifier permits only some bytecode sequences in valid programs, e.g

Code verification also ensures that arbitrary bit patterns cannot get used as an address. Memory protection is achieved without the need for a memory management unit (MMU). Thus, JVM is an efficient way to get memory protection on simple architectures that lack an MMU. This is analogous to managed code in Microsoft's .NET Common Language Runtime, and conceptually similar to capability architectures such as the Plessey 250, and IBM System/38.

A formal framework for the Java bytecode language and verifier

Java Virtual Machine - Bytecode instructions
The JVM has instruction (computer science)|instructions for the following groups of tasks:

* dynamic memory allocation|Object creation and manipulation

* branch (computer science)|Control transfer (branching)

* subroutine|Method invocation and return

* monitor (synchronization)|Monitor-based concurrency

The aim is binary compatibility. Each particular host operating system needs its own implementation of the JVM and runtime. These JVMs interpret the bytecode semantically the same way, but the actual implementation may be different. More complex than just emulating bytecode is compatibly and efficiently implementing the Java Class Library|Java core API that must be mapped to each host operating system.

Java Virtual Machine - C to bytecode compilers
From the viewpoint of a compiler, the Java virtual machine is just another processor with an instruction set, Java bytecode, for which code can be generated. The JVM was originally designed to execute programs written in the Java language. However, the JVM provides an execution environment in the form of a bytecode instruction set and a runtime system that is general enough that it can be used as the target for compilers of other programming language|languages.

That requires C (programming language)|C to bytecode compilers to provide their own lax machine abstraction, for instance producing compiled code that uses a Java array to represent main memory (so pointers can be compiled to integers), and linking the C library to a centralized Java class that emulates system calls

* [ NestedVM] translates C to MIPS machine language first before converting to Java bytecode.

* [ Cibyl] works similarly to NestedVM but targets J2ME devices.

* [ C2J] is also GCC-based, but it produces intermediary Java source code before generating bytecode. Supports the full ANSI C runtime. Available as a Win32 binary or as a Java executable.

* [ Java Backend for GCC], possibly the oldest project of its kind, was developed at The University of Queensland in 1999.

* [ Javum] is an attempt to port the full GNU environment to the JVM, and includes one of the above compilers packaged with additional utilities.

Compilers targeting Java bytecode have been written for other programming languages, including Ada (programming language)|Ada and COBOL.

Byte Code Engineering Library
The 'Byte Code Engineering Library' (BCEL) is a project sponsored by the Apache Foundation previously under their Jakarta Project|Jakarta charter to provide a simple API for decomposing, modifying, and recomposing binary Java (programming language)|Java classes (I.e. bytecode). The project was conceived and developed by Markus Dahm prior to officially being donated to the Apache Jakarta foundation on 27 October 2001.

Byte Code Engineering Library - Uses
BCEL provides a simple library that exposes the internal aggregate components of a given Java class through its API as object constructs (as opposed to the disassembly of the lower-level opcodes). These objects also expose operations for modifying the binary bytecode, as well as generating new bytecode (via injection of new code into the existing code, or through generation of new classes altogether.) The BCEL library has been used in several diverse applications, such as:

*Java Bytecode Decompiling, Obfuscation, and Refactoring

:Instrumentation calls that capture performance metrics can be injected into Java class binaries to examine memory/coverage data. (For example, injecting instrumentation at entry/exit points.)

*Implementation of New Language Semantics

:For example, Aspect oriented programming|Aspect-Oriented additions to the Java language have been implemented by using BCEL to decompose class structures for point-cut identification, and then again when reconstituting the class by injecting aspect-related code back into the binary. (See: AspectJ)

:FindBugs uses BCEL to analyze Java bytecode for code idioms which indicate bugs.

Interpreter (computer software) - Bytecode interpreters
The same approach is used with the Forth (programming language)|Forth code used in Open Firmware systems: the source language is compiled into F code (a bytecode), which is then interpreted by a virtual machine.

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