Correlated failures

The theory behind the error correction in RAID assumes that failures of drives are independent. Given these assumptions it is possible to calculate how often they can fail and to arrange the array to make data loss arbitrarily improbable.

In practice, the drives are often the same ages, with similar wear. Since many drive failures are due to mechanical issues which are more likely on older drives, this violates those assumptions and failures are in fact statistically correlated. In practice then, the chances of a second failure before the first has been recovered is not nearly as unlikely as might be supposed, and data loss can, in practice, occur at significant rates.

A common misconception is that “server-grade” drives fail less frequently than consumer-grade drives. Two independent studies, one by Carnegie Mellon University and the other by Google, have shown that the “grade” of the drive does not relate to failure rates.

Atomicity

This is a little understood and rarely mentioned failure mode for redundant storage systems that do not utilize transactional features. Database researcher Jim Gray wrote “Update in Place is a Poison Apple” during the early days of relational database commercialization. However, this warning largely went unheeded and fell by the wayside upon the advent of RAID, which many software engineers mistook as solving all data storage integrity and reliability problems. Many software programs update a storage object “in-place”; that is, they write a new version of t

However, very few storage systems provide support for atomic writes, and even fewer specify their rate of failure in providing this semantic. Note that during the act of writing an object, a RAID storage device will usually be writing all redundant copies of the object in parallel, although overlapped or staggered writes are more common when a single RAID processor is responsible for multiple drives. Hence an error that occurs during the process of writing may leave the redundant copies in different states, and furthermore may leave the copies in neither the old nor the new state. The little known failure mode is that delta logging relies on the original data being either in the old or the new state so as to enable backing out the logical change, yet few storage systems provide an atomic write semantic on a RAID disk.

While the battery-backed write cache may partially solve the problem, it is applicable only to a power failure scenario.

Since transactional support is not universally present in hardware RAID, many operating systems include transactional support to protect against data loss during an interrupted write. Novell Netware, starting with version 3.x, included a transaction tracking system. Microsoft introduced transaction tracking via the journaling feature in NTFS. Ext4 has journaling with checksums; ext3 has journaling without checksums but an “append-only” option, or ext3COW (Copy on Write). If the journal itself in a filesystem is corrupted though, this can be problematic. The journaling in NetApp WAFL file system gives atomicity by never updating the data in place, as does ZFS. An alternative method to journaling is soft updates, which are used in some BSD-derived system’s implementation of UFS.

This can present as a sector read failure. Some RAID implementations protect against this failure mode by remapping the bad sector, using the redundant data to retrieve a good copy of the data, and rewriting that good data to the newly mapped replacement sector. The UBE (Unrecoverable Bit Error) rate is typically specified at 1 bit in 1015 for enterprise class disk drives (SCSI, FC, SAS) , and 1 bit in 1014 for desktop class disk drives (IDE/ATA/PATA, SATA). Increasing disk capacities and large RAID 5 redundancy groups have led to an increasing inability to successfully rebuild a RAID group after a disk failure because an unrecoverable sector is found on the remaining drives. Double protection schemes such as RAID 6 are attempting to address this issue, but suffer from a very high write penalty.

Write cache reliability

The disk system can acknowledge the write operation as soon as the data is in the cache, not waiting for the data to be physically written. This typically occurs in old, non-journaled systems such as FAT32, or if the Linux/Unix “writeback” option is chosen without any protections like the “soft updates” option (to promote I/O speed whilst trading-away data reliability). A power outage or system hang such as a BSOD can mean a significant loss of any data queued in such a cache.

Often a battery is protecting the write cache, mostly solving the problem. If a write fails because of power failure, the controller may complete the pending writes as soon as restarted. This solution still has potential failure cases: the battery may have worn out, the power may be off for too long, the disks could be moved to another controller, the controller itself could fail. Some disk systems provide the capability of testing the battery periodically, however this leaves the system without a fully charged battery for several hours.

An additional concern about write cache reliability exists, specifically regarding devices equipped with a write-back cache—a caching system which reports the data as written as soon as it is written to cache, as opposed to the non-volatile medium. The safer cache technique is write-through, which reports transactions as written when they are written to the non-volatile medium.

Equipment compatibility

The methods used to store data by various RAID controllers are not necessarily compatible, so that it may not be possible to read a RAID array on different hardware, with the exception of RAID1, which is typically represented as plain identical copies of the original data on each disk. Consequently a non-disk hardware failure may require the use of identical hardware to recover the data, and furthermore an identical configuration has to be reassembled without triggering a rebuild and overwriting the data. Software RAID however, such as implemented in the Linux kernel, alleviates this concern, as the setup is not hardware dependent, but runs on ordinary disk controllers, and allows the reassembly of an array. Additionally, individual RAID1 disks (software, and most hardware implementations) can be read like normal disks when removed from the array, so no RAID system is required to retrieve the data. Inexperienced data recovery firms typically have a difficult time recovering data from RAID drives, with the exception of RAID1 drives with conventional data structure.

Data recovery in the event of a failed array

With larger disk capacities the odds of a disk failure during rebuild are not negligible. In that event the difficulty of extracting data from a failed array must be considered. Only RAID 1 stores all data on each disk. Although it may depend on the controller, some RAID 1 disks can be read as a single conventional disk. This means a dropped RAID 1 disk, although damaged, can often be reasonably easily recovered using a software recovery program. If the damage is more severe, data can often be recovered by professional data recovery specialists. RAID5 and other striped or distributed arrays present much more formidable obstacles to data recovery in the event the array fails.

Drive error recovery algorithms

Many modern drives have internal error recovery algorithms that can take upwards of a minute to recover and re-map data that the drive fails to easily read. Many RAID controllers will drop a non-responsive drive in 8 seconds or so. This can cause the array to drop a good drive because it has not been given enough time to complete its internal error recovery procedure, leaving the rest of the array vulnerable. So-called enterprise class drives limit the error recovery time and prevent this problem, but desktop drives can be quite risky for this reason. A fix is known for Western Digital drives. A utility called WDTLER.exe can limit the error recovery time of a Western Digital desktop drive so that it will not be dropped from the array for this reason. The utility enables TLER which limits the error recovery time to 7 seconds. Western Digital enterprise class drives are shipped from the factory with TLER enabled to prevent being dropped from RAID arrays. Similar technologies are used by Seagate, Samsung, and Hitachi.

Increasing recovery time

Drive capacity has grown at a much faster rate than transfer speed, and error rates have only fallen a little in comparison. Therefore, larger capacity drives may take hours, if not days, to rebuild. The re-build time is also limited if the entire array is still in operation at reduced capacity. Given a RAID array with only one disk of redundancy (RAIDs 3, 4, and 5), a second failure would cause complete failure of the array, as the mean time between failure (MTBF) is high.

Operator skills, correct operation

In order to provide the desired protection against physical drive failure, a RAID array must be properly set up and maintained by an operator with sufficient knowledge of the chosen RAID configuration, array controller (hardware or software), failure detection and recovery. Unskilled handling of the array at any stage may exacerbate the consequences of a failure, and result in downtime and full or partial loss of data that might otherwise be recoverable.

Particularly, the array must be monitored, and any failures detected and dealt with promptly. Failure to do so will result in the array continuing to run in a degraded state, vulnerable to further failures. Ultimately more failures may occur, until the entire array becomes inoperable, resulting in data loss and downtime. In this case, any protection the array may provide merely delays this.

The operator must know how to detect failures or verify healthy state of the array, identify which drive failed, have replacement drives available, and know how to replace a drive and initiate a rebuild of the array.

Other problems and viruses

While RAID may protect against physical drive failure, the data is still exposed to operator, software, hardware and virus destruction. Many studies cite operator fault as the most common source of malfunction, such as a server operator replacing the incorrect disk in a faulty RAID array, and disabling the system (even temporarily) in the process. Most well-designed systems include separate backup systems that hold copies of the data, but don’t allow much interaction with it. Most copy the data and remove the copy from the computer for safe storage.

Adapted from the Wikipedia article RAID, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Early uses in personal names

Medial capitals have always been used (albeit sporadically) in English, for example, as a traditional spelling style for certain surnames, such as in Scottish MacLean (originally, “son of Gillean”) and Hiberno-Norman FitzGerald (“son of Gerald”). This same convention is sometimes used in English for surnames of foreign origin which include prepositions or other particles, e.g., DuPont (from French ”Dupont” or ”du Pont”), DiCaprio (from Italian ”di Caprio”) and VanDyke (from Dutch ”van Dijk”). The actress ZaSu Pitts, whose fame peaked in the 1930s and 1940s, sometimes spelt her given name in camel case, emphasizing its derivation from two other names.

Chemical formulae

The first systematic and widespread use of medial capitals for technical purposes was the notation for chemical formulae invented by the Swedish chemist Berzelius in 1813. To replace the multitude of naming and symbol conventions used by chemists until that time, he proposed to indicate each chemical element by a symbol of one or two letters, the first one being capitalized. The capitalization allowed formulae like ‘NaCl’ to be written without spaces and still be parsed without ambiguity.

Berzelius’s system remains in use to this day, augmented with three-letter symbols like ‘Uuq’ for unnamed elements; and has been extended to describe the aminoacid sequences of proteins and other similar domains. Internal capitalization has also been used for other technical codes

”The King’s English”

In their English style guide ”The King’s English”, first published in 1906, H. W. Fowler and F. G. Fowler suggested that medial capitals could be used in triple compound words where hyphens would cause ambiguity—the examples they give are “KingMark-like” (as against “King Mark-like”) and “Anglo-SouthAmerican” (as against “Anglo-South American”). However, they described the system as “too hopelessly contrary to usage at present.”

Early use in trademarks

Since the mid-20th century, medial capitals have occasionally been used for corporate names and product trademarks, such as

* CinemaScope and VistaVision, rival widescreen movie formats (1953)

* ShopKo (1962)

* ”MisteRogers”, the Canadian version of ”Mister Rogers’ Neighborhood” (1962)

* AstroTurf (1967)

* ConAgra, formerly Consolidated Mills (1971).

Computer programming

In the 1970s and 1980s, medial capitals were adopted as a standard or alternative naming convention for multi-word identifiers in several programming languages. The origin of this convention has not yet been settled. However a 1954 conference proceedings informally referred to IBM’s Speedcoding system as “SpeedCo”.

Background: multi-word identifiers

Computer programmers often need to write descriptive (hence multi-word) identifiers, like “previous balance” or “end of file”, in order to improve the readability of their code. However, most popular programming languages forbid the use of spaces inside identifiers, since they are interpreted as delimiters between tokens. The alternative of writing the words together as in “endoffile” is not satisfactory, since the word boundaries may be quite difficult to discern in the result.

Some early programming languages, notably Lisp (1958) and COBOL (1959), addressed this problem by allowing a hyphen (“-”) to be used between words of compound identifiers, as in “END-OF-FILE”. However, this solution was not adequate for algebraic-oriented languages such as FORTRAN (1955) and ALGOL (1958), which used the hyphen as an intuitively-obvious subtraction operator. (FORTRAN also restricted identifiers to six characters or fewer at the time, preventing multi-word identifiers except those made of very short words.) Since the common punched card character sets of the time had no lower-case letters and no other special character that would be adequate for the purpose, those early languages had to do without multi-word identifiers.

It was only in the late 1960s that the widespread adoption of the ASCII character set made both lower case and the underscore character “_” universally available. Some languages, notably C, promptly adopted underscores as word separators; and underscore-separated compounds like “end_of_file” are still prevalent in C programs and libraries. However, some languages and programmers chose to avoid underscores and adopted camel case instead. Two accounts are commonly given for the origin of this convention.

The “Lazy Programmer” theory

One theory for the origin of the camel case convention holds that C programmers and hackers simply found it more convenient than the standard underscore-based style.

The underscore key is inconveniently placed on QWERTY keyboards. Additionally, in some fonts the underscore character can be confused with a minus sign; it can be overlooked because it falls below the string of characters or it can be lost entirely when displayed or printed underlined or when printed on a dot-matrix printer with a defective pin or misaligned ribbon. Moreover, early compilers severely restricted the length of identifiers (e.g., to 8 or 14 letters) or silently truncated all identifiers to that length. Finally, the small size of computer displays available in the 1970s encouraged the use of short identifiers. Many C programmers opted to use camel case instead of underscores, for it yielded legible compound names with fewer keystrokes and fewer characters.

The “Alto Keyboard” theory

Another account claims that the camel case style first became popular at Xerox PARC around 1978, with the Mesa programming language developed for the Xerox Alto computer. This machine lacked an underscore key and the hyphen and space characters were not permitted in identifiers, leaving CamelCase as the only viable scheme for readable multiword names. The PARC Mesa Language Manual (1979) included a coding standard with specific rules for Upper- and lowerCamelCase which was strictly followed by the Mesa libraries and the Alto operating system.

The Smalltalk language, which was developed originally on the Alto and became quite popular in the early 1980s, may have been instrumental in spreading the style outside PARC. Camel case was also used by convention for many names in the PostScript page description language (invented by Adobe Systems founder and ex-PARC scientist John Warnock), as well as for the language itself. A further boost was provided by Niklaus Wirth (the inventor of Pascal) who acquired a taste for camel case during a sabbatical at PARC and used it in Modula, his next programming language.

Spread to mainstream usage

Whatever its origins within the computing world, camel case spread to a wider audience in the 1980s and 1990s, when the advent of the personal computer exposed hacker culture to the world. Camel case then became fashionable for corporate trade names, first in computer-related fields but later expanding further into the mainstream. Examples ranging from the 1970s to the 2000s give a history of the spread of the usage:

* (1977) CompuServe, UnitedHealthCare (now UnitedHealthcare)

* (1979) MasterCard, SportsCenter, VisiCalc

* (1980) EchoStar

* (1982) MicroProse, WordPerfect

* (1983) NetWare

* (1984) BellSouth, LaserJet, MacWorks, iDEN

* (1985) PageMaker, EastEnders

* (1986) SpaceCamp

* (1987) ClarisWorks, HyperCard, PowerPoint

* (1990) HarperCollins, SeaTac

* (1991) SuperAmerica, TriStar Pictures (formerly Tri-Star Pictures)

* (1992) OutKast, ThinkPad, IndyCar

* (1993) AmeriCorps, EcoPark, ValuJet (now AirTran Airways), SolidWorks

* (1994) PlayStation, easyJet (an early use of CamelCase with lowercase first letter)

* (1995) WorldCom (now MCI), eBay

* (1996) RadioShack (formerly Radio Shack)

* (1997) TiVo

* (1998) DaimlerChrysler, PricewaterhouseCoopers, iMac

* (1999) BlackBerry, DragonForce, SpongeBob SquarePants, WWE SmackDown, jetBlue, ExxonMobil

* (2000) FedEx (formerly Federal Express), GlaxoSmithKline, PayPal

* (2001) AmerisourceBergen, Nintendo GameCube, ProQuest

* (2003) MySpace

* (2004) Pokémon FireRed and LeafGreen

* (2005) YouTube, PetSmart (formerly PETsMART)

* (2006) WikiLeaks

* (2007) MillerCoors

* (2008) Fort Wayne TinCaps, Empire Cinemas MoviEmail, WaqarTech

During the dot-com bubble of the late 1990s, the lowercase prefixes “e” (for “electronic”) and “i” (for “Internet”, “information”, “intelligent” etc.) became quite common, giving rise to some camel case names like Apple’s iMac and the eBox software platform.

In 1998, Dave Yost suggested that chemists use medial capitals to aid readability of long chemical names, e.g. write AmidoPhosphoRibosylTransferase instead of amidophosphoribosyltransferase.

This practice is sometimes given to the abbreviated names of certain neighborhoods, particularly New York City neighborhoods, such as ”SoHo” (”So”uth of ”Ho”uston Street) and ”TriBeCa” (”Tri”angle ”Be”low ”Ca”nal Street). CamelCase is not always used and the neighborhoods are instead rendered as ”Soho” and ”Tribeca”.

History of the name “camel case”

The original name of the practice, used in media studies, grammars and the ”Oxford English Dictionary”, was “medial capitals”. The fancier names such as “InterCaps”, “CamelCase” and variations thereof are relatively recent and seem more common in computer-related communities.

The earliest known occurrence of the term “InterCaps” on Usenet is in an April 1990 post to the group alt.folklore.computers by Avi Rappoport, with “BiCapitalization” appearing slightly later in a 1991 post by Eric S. Raymond to the same group. The earliest use of the name “CamelCase” occurs in 1995, in a post by Newton Love. “”With the advent of programming languages having these sorts of constructs, the humpiness of the style made me call it HumpyCase at first, before I settled on CamelCase. I had been calling it CamelCase for years,”” said Love, “”The citation above was just the first time I had used the name on USENET.””

The name “CamelCase” is not related to the “Camel Book” (”Programming Perl”), which uses all-lowercase identifiers with underscores in its sample code.

Adapted from the Wikipedia article CamelCase, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Alan Ashton and Bruce Bastian founded Satellite Systems International, Inc. of Orem, Utah, which later renamed itself WordPerfect Corporation. Originally written for Data General minicomputers, in 1982 the developers ported the program to the IBM PC as WordPerfect 2.20, continuing the version numbering of the Data General series.

The program’s popularity took off with the introduction of WordPerfect 4.2 in 1986, with automatic paragraph numbering (important to the law office market), and the splitting of a lengthy footnote and its partial overflow to the bottom of the next page, as if it had been professionally typeset (valuable to both the law office and academic markets). WordPerfect 4.2 became the first program to overtake the original market leader (WordStar, the leading word processing program) in a major application category on the DOS platform.

On 6 November 1989, WordPerfect Corporation released the program’s most successful version ever, WordPerfect 5.1 for DOS, which was the first version to include Macintosh-style pull-down menus to supplement the traditional F-key combinations, as well as support for tables, a spreadsheet-like feature.

The data format used by WordPerfect 5.1 was, for years, the most portable format in the world. All word processors could read (and convert) that format. Many conferences and magazines insisted that people ship their documents in 5.1 format. Unlike previous DOS versions, WordPerfect 6.0 for DOS could switch between its traditional text-based editing mode and a graphical editing mode that showed the document as it would

Key characteristics

To this day, WordPerfect’s three major characteristics that have differentiated it from other market-leading word processors are its streaming code architecture, its Reveal Codes feature, and its unusually user-friendly macro/scripting language, PerfectScript.

Streaming code architecture

A key to WordPerfect’s design is its streaming code architecture that parallels the formatting features of HTML and Cascading Style Sheets. Documents are created much the same way that raw HTML pages are written, with text interspersed by tags (called “codes”) that trigger treatment of data until a corresponding closing tag is encountered, at which point the settings active to the point of the opening tag resume control. As with HTML, tags can be nested. Some data structures are treated as objects within the stream as with HTML’s treatment of graphic images, e.g., footnotes and styles, but the bulk of a WordPerfect document’s data and formatting codes appear as a single continuous stream. A difference between HTML tags and WordPerfect codes is that HTML codes can all be expressed as a string of plain text characters delimited by greater-than and less-than characters, e.g. text whereas WordPerfect formatting codes consist of hexadecimal characters.

Styles and style libraries

The addition of styles and style libraries in WP 5.0 provided greatly increased power and flexibility in formatting documents, while maintaining the streaming-code architecture of earlier versions. Prior to that, WordPerfect’s only use of styles (a particular type of programming object) was the Opening Style, which contained the default settings for a document.

Reveal codes

The Reveal Codes feature is a second editing screen that can be toggled open and closed at the bottom of the main editing screen. Text is displayed in Reveal Codes interspersed with tags and the occasional objects, with the tags and objects represented by named tokens. The scheme makes it far easier to untangle coding messes than with styles-based word processors, and object tokens can be clicked with a pointing device to directly open the configuration editor for the particular object type, e.g. clicking on a style token brings up the style editor with the particular style type displayed. WordPerfect users forced to change word processors by employers frequently complain on WordPerfect online forums that they are lost without Reveal Codes. Because of their style dependencies, efforts to create the equivalent of Reveal Codes in other word processors have produced dissimilar results. Note that WordPerfect had this feature already in its DOS incarnations: it could be brought forward by pressing the keys Alt and F3 together.

Macro languages

WordPerfect for DOS was notable for its Alt-keystroke macro facility, which was expanded with the addition of macro libraries in WP 5.0 that also allowed for Ctrl-keystroke macros, and remapping of any key as a macro. This enabled any sequence of keystrokes to be recorded, saved, edited, and recalled. Macros could examine system data, make decisions, be chained together, and operate recursively until a defined ‘stop’ condition was met. This capability provided an amazingly powerful way to rearrange data and formatting codes within a document, where the same sequence of actions needed to be performed repetitively e.g. for tabular data. Macros can also be edited using WordPerfect Program Editor. This facility, however, could not be ported easily to the subsequent Windows versions.

A new and even more powerful interpreted token-based macro recording and scripting language was introduced for both DOS and Windows 6.0 versions, and that became the basis of the language named PerfectScript in later versions. PerfectScript has remained the mainstay scripting language for WordPerfect users ever since. PerfectScript was designed specifically to be user-friendly, thus avoiding far less user-friendly methods of scripting languages implemented on other word processing programs that require education in advanced programming concepts such as Object Oriented Programming in order to produce useful yet sophisticated and powerful macros.

An important property of WordPerfect macros is that they are not embedded in a document. As a result, WordPerfect is not prone to macro viruses or malware, unlike MS Word. Despite the term “macro”, the language has hundreds of commands and functions and in fact creates full-fledged programs resident on and executed on the user’s computer. In WPDOS 6 the source code is generated using the same interface used to edit documents. A WordPerfect macro can create or modify a document or perform tasks such as displaying results of a calculation such as taking a date input, adding a specific number of days and displaying the new date in a dialog box. Documents created or edited by a WordPerfect macro are no different from those produced by manual input; the macros simply improve efficiency or automate repetitive tasks.

Function keys

Like its mid-1980s competitor, MultiMate, WordPerfect used almost every possible combination of function keys with Ctrl, Alt, and Shift modifiers. (See example help screen on this page.) This was in contrast to WordStar, which used only Ctrl, in conjunction with traditional typing keys. Many people still know and use the function key combinations from the DOS version, which were originally designed for Data General Dasher VDUs that supported two groups of five plain, shift, control, and control shift function keys. This was translated to the layout of the 1981 IBM PC keyboard, with two columns of function keys at the left end of the keyboard, but worked even better with the 1984 PC AT keyboard with three groups of four function keys across the top of the keyboard. With the 1981 PC keyboard, the Tab key and the related F4 (”Indent”) functions were adjacent. This plethora of keystroke possibilities, combined with the developers’ wish to keep the user interface free of “clutter” such as on-screen menus, made it necessary for most users to use a keyboard template showing each function. WordPerfect used F3 instead of F1 for ”Help”, F1 instead of Esc for ”Cancel”, and Esc for ”Repeat” (though a configuration option in later versions allowed these functions to be rotated to locations that later became more standard).

Printer drivers

WordPerfect for DOS shipped with an impressive array of printer drivers& — a feature that played an important role in its adoption& — and also shipped with a printer driver editor called PTR, which features a flexible macro language and allows technically-inclined users to customize and create printer drivers.

Internally, WordPerfect used an extensive WordPerfect character set as its internal code. The precise meaning of the characters, although clearly defined and documented, can be overridden in its customizable printer drivers with PTR.

The relationship between different type faces and styles, and between them and the various sections in the WordPerfect character set, were also described in the printer drivers and can be customized through PTR.

An interesting feature of the DOS 5.0 version was its Type-Through feature. It allowed a user with certain compatible printers to use Word Perfect as a conventional typewriter. This functionality was removed in the DOS 5.1 version. (Word Perfect Made Easy, Mincberg, 1990, p485)

WordPerfect Library/Office

WordPerfect Corporation produced a variety of ancillary and spin-off products. WordPerfect Library (introduced in 1986 and later renamed WordPerfect Office) was a package of network and stand-alone utilities for use with WordPerfect, primarily developed for offices running Novell NetWare. WordPerfect Library/Office included the DOS antecedents of what is now known as Novell GroupWise, a shareable package of contact management, calendaring, and related word processing utilities. WordPerfect Library/Office& — a brand name later revived by Corel after it acquired ownership of WordPerfect and other programs still bundled under that product name as of this writing& — included amongst other utilities a local area network (LAN) email facility, and was the most popular such package in its day.

WordPerfect Shell

The Library/Office bundle also included a noteworthy task-switching program that ran as a shell atop DOS, branded as WordPerfect Shell. Task-switchers were a popular application type for the DOS operating system because of its lack of multi-tasking, making it impractical to have many applications running at once. Task-switchers were programs that allocated available memory between open applications, allowing fast switching between open applications whose actions were suspended when the user switched to a different program. WordPerfect Shell 4.0, which was also bundled with the WordPerfect 6.x versions, had most functionality of the Windows 3.x shell but was far more versatile. Its automated memory management was superior to that of the Microsoft Windows shell, and Microsoft’s product generally performed with far fewer frequent memory glitches when Windows was run as a program under Shell 4.0.

The user interface for Shell is based on a hierarchical menu metaphor rather than the windows/folders/icons metaphor used by Microsoft. Shell 4.0′s menu structures could be individually hot-keyed as pop-ups, and its powerful menu editor allowed fast creation and editing of menu structures and menu items, with each menu item quickly configurable for entry of command lines and menu names. Shell 4.0 included 80 programmable clipboards, and the menu structures and menu items were also programmable using a scripting language whose scripts could themselves be chained to and from WordPerfect macros. The scripting language also included a keyboard buffer stuffing tool for control and operation of non-WordPerfect applications. Microsoft Windows had no answer to such powerful features other than a glitz of windows, icons, pointing devices, and an overwhelming marketing strategy. WordPerfect Shell was laid to rest along with many other popular DOS character-based tools inundated by Microsoft’s marketing of Windows 95. Novell later licensed Shell 3.0 and 4.0 for free distribution. As of this writing it is still downloadable from the DataPerfect Users Group.

WordPerfect Library/Office also included a Calculator, a flat-file database called Notebook that could be used by itself or in WordPerfect document merges, an exceptionally powerful relational database& — DataPerfect& — that retains a small but dedicated following despite having been dropped by WordPerfect Corporation in favour of Borland’s Paradox as a companion of WP for Windows. Additional features continue to be added from time to time by DataPerfect’s author, Lew Bastian& — Bruce Bastian’s older brother& — a programmer who had written some of IBM’s earliest disk-caching patents, and DataPerfect can now run as web server. LetterPerfect was a scaled down version of WordPerfect with the more advanced features removed but with file and (for the most part) keystroke compatibility.

An implementation of Microsoft Visual Basic for Applications (VBA), introduced with WordPerfect for Windows 9.0, provides a full-featured development environment for building advanced custom WordPerfect solutions. These solutions are often created by corporate developers or programmers and may not be easily accessible to the typical WordPerfect user. For these users, PerfectScript is the better option.

People who code scripts for WordPerfect use the Macros & Merges forum at [http://www.wpuniverse.com WordPerfect Universe] as their primary meeting ground. That site is a collaboration among other WordPerfect-related web site operators and others and functions as a portal to WordPerfect resources on the web. The site also maintains an extensive clip library for use in PerfectScript programming, has the Web’s largest metalink library for locating online WordPerfect resources, and has the only peer-to-peer forum on the Web for DOS WordPerfect.

The WordPerfect template and document file formats have remained remarkably stable since the WordPerfect 6.x DOS and Windows versions. Complete backward compatibility has been maintained and all WordPerfect versions since 6.0 have included a feature that stores any unrecognized codes in stream location represented in Reveal Codes by an “Unknown” token. Documents generated on newer versions can thus be edited in older versions with the codes retained. Then, upon being reopened in a newer version of WordPerfect, the “unknown” tokens regain their functionality. None of the newer WordPerfect features reflected in the file formats cause data loss when opened in older versions.

LetterPerfect

In 1990 WordPerfect Corporation also offered LetterPerfect, which was a reduced-functionality version of WP-DOS 5.1 intended as an entry-level product for students and home users. It did not support macros, tables, labels, sorting, equation editing or styles. It sold for about $100 but didn’t catch on and was soon discontinued.

Adapted from the Wikipedia article WordPerfect, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Libraries

The college has a spacious library with a total covered area of 1270 sq.m. having reading room capacity of 200 students. The library contains books from national and international publishers in different disciplines including text books, reference books, handbooks, encyclopedia, reports and general books. One hundred latest Journals and Magazines add value to the library. A Book Bank facility to cater to the requirement of needy students has also been set up to provide books in all subjects for full semester duration. The library also has Reprographic Facility for the college.

The library is fully automated and uses the LIMS (Library Information Management System Software) software.

Computing Facilities

The Institute is equipped with sophisticated computer labs with more than 645 high quality Pentium IV machines from Compaq/ IBM/ LG/ Zenith having latest softwares . The Main Highlights of these labs/ machines are:

All labs are equipped and inter connected with high speed switch networking.

Facilities like printers and scanners are provided in each and every computer lab.

24 hr. internet facility with dedicated 4 mbps 1:1 bandwidth and backed up with high speed ISDN line.

All computer labs are air-conditioned and upgradation of softwares is synchronized with changing syllabus and other prescribed standards.

Software

The Computer labs are equipped with the latest softwares and their extensive use has enabled students to grasp them effectively.

The different softwares available are:

OS Platforms

Windows XP, Vista, etc.

( MSDN Subscription )

Enterprise Linux, Redhat Fedora 8,9,10, Centos

Advanced Servers ( 2003,2008)

Windows NT

Novell Netware

Databases

Oracle 9i

MS Access

Developer 2000

Mysql, Postgresql

MS SQL Server

Programming Languages

Turbo C/ C++ , gcc

Pascal

Cobol

Java

Verilog (VHDL)

Lisp

Prolog

Flash

Auto Cad

Development Tools & Utilities.

Visual Studio Net

Visual Basic

Net beans

Corporate Network Anti Virus.

Packages

MS Office 2003/XP , MSDN AA

Dbase (IV) , Coreldraw, Piece Pice (Orcad )

Photoshop , Autocad, Catia, Ansys, Vhdl, Matlab.

Lex (Compiler Design Tool)

8085/8086 Microprocessor Simulator

Hardware

The Computer Labs have latest branded P-IV computer hardware like Compaq, Zenith, Multimedia Projector, Web Cameras, Mail Server,

CCTV, Voip, Router etc. All hardware labs are being maintained by a qualified Systems Engineer.

Computer Science/ Information Technology Labs

Compiler Design

Computer Graphics

Data Structures and Algorithms

Fundamentals of Computer Programming

Fundamentals of Computer Science

Java

Linux

Logic and Functional Programming

Multimedia

Networking

Object Oriented Programming Systems

Operating Systems

Oracle

Programming Languages

Project

Software Packages

Visual Studio

Adapted from the Wikipedia article PDM College of Engineering, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

The original SoftICE for DOS was written in 1987 by NuMega founders Frank Grossman and Jim Moskun. The program, written in 80386 assembly language, played the role of an operating system and ran software in virtual 8086 mode. It sold for $386.

SoftICE/W (for Windows) was developed in the 1990s, and was instrumental in the Writing of “Undocumented Windows”, by Andrew Schulman, David Maxey and Matt Pietrek. SoftIce/W was derived from an earlier, lesser known product, SoftICE for Netware (32-bit protected mode). One of the key advantages it had over Microsoft’s debuggers is that it enabled single machine debugging, rather than requiring a second machine to be connected over a serial port.

The principal developers of SoftICE were Dom Basile (‘Mr. SoftICE’), Tom Guinther (Kitchen Sink, Symbol Engine), Gerald Ryckman (Video Drivers and Kitchen Sink), Ray Hsu (Video Drivers W95), and Dan Babcock (SoftICE/NT 3.1/3.5: Universal Video Driver, Symbol Engine), with contributions by a variety of NuMega developers including Frank Grossman, Jim Moskun and Matt Pietrek.

In 1995 the codebase for SoftICE/95 was ported to run on the Windows NT platform.

Newer versions of SoftICE patch deep into Microsoft Windows. As such, old versions of SoftICE are rarely compatible with new versions of Windows. Compuware therefore offers SoftICE as a subscription so that it can be kept up to date and in sync with the latest Microsoft Windows version.

It used to be offered as part of Compuware’s DriverStudio package but was discontinued in April 2006.

> Termination

As of April 3, 2006 the DriverStudio product family has been discontinued because of “a variety of technical and business issues as well as general market conditions”. Maintenance support was offered until March 31, 2007.

Anti – SoftICE measures

Probably most of those “technical and business issues” leading to the abandonment of SoftICE have to do with lots of countermeasures software vendors have put in place in order to fend themselves from people employing SoftICE as a tool.

These counter measures vary in a wide range. For example, here, we have a code some vendors used to detect the presence of SoftICE running in the same machine in the early stages of the counter measures tactics:

mov eax, dword ptr [pIDT+2] ; eax -> IDT

add eax, 8 ; eax -> int 1 vector

mov ebx, [eax] ; ebx == int 1 vector

add eax, 16 ; eax -> int 3 vector

mov eax, [eax] ; eax == int 3 vector

and eax, 0ffffh ; strip the selector

and ebx, 0ffffh ; part of it

sub eax, ebx ; find displacement

cmp eax, 10h ;

jne HackedVector ; if it isn’t equal, then chances are

; SoftICE had tampered with these vectors

These measures have evolved since, not only in quantity, but in quality. While most of them can only deter the less experienced and determined hackers, SoftICE is no longer a newbie tool of choice.

Today vendor’s defenses are based on more sophisticated packers/protectors, e.g. Themida, Armadillo or ASProtect which pack the program code and tamper with entry point addresses so it is hard to find the program’s original entry point (OEP). That is also true for the program’s import address table (IAT). However tools for hiding SoftICE are also available, such as IceStealth and IceExt for Windows NT, or Icedump and IcePatch for Windows 9x.[http://www.woodmann.com/collaborative/tools/index.php/Category:SoftICE_Extensions]

Adapted from the Wikipedia article SoftICE, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

]]>

Major embedded database products include, in alphabetical order:

Berkeley DB from Oracle Corporation, EffiPRoz from [http://www.EffiProz.com EffiProz Systems], ElevateDB from [http://www.elevatesoft.com Elevate Software, Inc.], Empress Embedded Database from [http://www.empress.com Empress Software], Extensible Storage Engine from Microsoft, eX”treme”DB from McObject, Firebird Embedded, HSQLDB from HSQLDB.ORG, Informix Dynamic Server (IDS) from IBM, InnoDB from Oracle Corporation, ITTIA DB from [http://www.ittia.com/products ITTIA], RDM Embedded and RDM Server from [http://www.raima.com/ Raima Inc.], SolidDB from IBM, SQLite, SQL Server Compact from Microsoft Corporation, Valentina DB from Paradigma Software, VistaDB from VistaDB Software, Inc., and Advantage_Database_Server from Sybase Inc.

Advantage Database Server

Sybase’s Advantage Database Server (ADS) is a full-featured embedded database management system. It provides both ISAM and relational data access and is compatible with multiple platforms including Windows, Linux, and Netware. It is available as a royalty-free local file-server database or a full Client/Server version. ADS has been around for many years and is highly scalable, with no administration, and has support for a variety of IDEs including .NET, Delphi, FoxPro, PHP, VB, VO, Vulcan, Clipper, Perl, Java, xHarbour, etc.

EffiProz

Effiproz is a transactional, persistent in-memory SQL database engine written entirely in C#. SQL features include SQL Stored Procedures, Functions, Triggers,etc. Support .Net Framework 3.5, Sil

ElevateDB

ElevateDB is a royalty-free, SQL:2003-compliant, compact, embedded database engine available for Delphi (Win32), C++Builder (Win32), Lazarus (Win32/WinCE), Visual Studio (.NET and .NET CF), and any ODBC-compliant application. Under Delphi, Lazarus, and C++Builder, ElevateDB can be compiled directly into the application, whereas under .NET it is a single assembly and the ODBC driver is implemented as a single .DLL. ElevateDB operates in single-user, multi-user file-sharing, and client-server modes, and includes the ElevateDB Server for client-server operation.

Embedded InnoDB

Embedded InnoDB is a standalone, embeddable form of the InnoDB Storage Engine. Given that Embedded InnoDB is based on the same code base as the InnoDB Storage Engine, it contains many of the same features: high-performance and scalability, Multi-Version Concurrency Control (MVCC), row-level locking, deadlock detection, fault tolerance, automatic crash recovery, etc. However, because the embedded engine is completely independent from MySQL, it lacks server components such as networking, object-level permissions, etc. By eliminating the MySQL server overhead, InnoDB has a small footprint and is well-suited for embedding in applications which require high-performance and concurrency. As with most embedded database systems, Embedded InnoDB is designed to be accessed primarily with an ISAM-like C API rather than SQL (though an extremely rudimentary SQL variant is supported).

Empress Embedded Database

Empress Software, Inc., developer of the [http://www.empress.com Empress Embedded Database], is a privately held company founded in 1979. Empress Embedded Database is a full-function, relational database that has been embedded into applications by organizations small to large, with deployment environments including medical systems, network routers, nuclear power plant monitors, satellite management systems, and other embedded system applications that require reliability and power. Empress is an ACID compliant, SQL database engine with C, C++, Java, JDBC, ODBC, SQL, ADO.NET and kernel level APIs. Applications developed using these APIs may be run in standalone and/or server modes. Empress Embedded Database runs on Linux, Unix, Microsoft Windows and Real-time operating systems.

Extensible Storage Engine

ESE is an Indexed Sequential Access Method (ISAM) data storage technology from Microsoft. ESE is notably a core of Microsoft Exchange Server and Active Directory. Its purpose is to allow applications to store and retrieve data via indexed and sequential access. Windows Mail and Desktop Search in the Windows Vista operating system also make use of ESE to store indexes and property information respectively.

”e”X”treme”DB

McObject launched ”e”X”treme”DB as the first in-memory embedded database designed from scratch for real-time embedded systems. The initial product was soon joined by ”e”X”treme”DB High Availability (HA) for fault tolerant applications. The product family now includes 64-bit and transaction logging editions, and the hybrid ”e”X”treme”DB Fusion, which combines in-memory and on-disk data storage. In 2008, McObject introduced ”e”X”treme”DB Kernel Mode, the first embedded DBMS designed to run in the operating system kernel. Today, ”e”X”treme”DB is used in millions of real-time and embedded systems worldwide. McObject also offers Perst, an open source, object-oriented embedded database for Java, Java ME, .NET, .NET Compact Framework and Silverlight.

Firebird Embedded

Firebird Embedded is a relational database engine. It’s on OpenSource fork of InterBase, is A.C.I.D compliant, supports triggers and stored procedures, and is available on Linux and Win32 systems. It has the same features as the classic and superserver version of Firebird, except that two or more THREADS (not just applications) cannot access the same database at the same time. So Firebird embedded acts as a local server for a single threaded client accessing its databases (that means it doesn’t work properly for ASP.NET web applications, because there, each user has its own thread, which means two users could access the same database at the same time, but they would not be in the same thread, because ASP.NET opens a new thread for each user). It exports the standard Firebird API entrypoints. The main advantage of Firebird embedded databases is, that unlike SQlite or Access databases, they can be plugged-in to a full Firebird server without any modifications at all.

HSQLDB

HSQLDB is an opensource relational database management system with a BSD-like license that runs in the same Java Virtual Machine as the embedded application. HSQLDB supports a variety of in-memory and disk-based table modes, Unicode and SQL:2008.

Informix Dynamic Server

Informix Dynamic Server (IDS) is characterized as an “enterprise class embeddable database server”, combining embeddable features such as low footprint, programmable and autonomic capabilities with enterprise class database features such as high availability and flexible replication features. IDS is used in deeply embedded scenarios such as IP telephony call-processing systems, point of sale applications and financial transaction processing systems.

InfinityDB

InfinityDB is an all Java B+Tree Database Engine that is embeddable in the smallest to the largest applications that run on hand held devices, workstations, servers, or in distributed systems. InfinityDB provides a data integrity guarantee through all non-media failures, provides a simple API with only a few basic methods, and requires no administrative support. Version 2 offers full ACID transactionality without a log and with fine-grained locks. Programmers can superimpose their own data model, or employ the Entity-Attribute-Value model, by direct low-level access. The basic engine provides multi-valued or set attributes, all primitive Java types, unlimited Large Objects, heterogenous values, composite keys (Entities) and values, and unlimited sparse attributes, all extensible in-place with no schema changes.

InterBase

InterBase is a cross-platform, Unicode enabled SQL database platform able to be embedded within turn-key applications. Out of the box SMP support (Server Edition), SQL 92 compliance and support for Windows, Linux, Solaris, and Macintosh platforms. Ideal for small-to-medium enterprises.

ITTIA DB

ITTIA DB is a cross-platform embedded database for embedded system and intelligent mobile device software developers. ITTIA DB is a true relational database management system, supporting runtime SQL queries, isolation levels, write ahead logging, and B+ tree indexes. To support the wide variety of operating systems and hardware used in embedded development, ITTIA DB databases use a portable format that can be accessed with or without SQL through C and C++ APIs. Disk, memory, and hybrid databases are supported.

NexusDB

NexusDB is the commercial successor to the [http://sourceforge.net/projects/tpflashfiler/ FlashFiler] database which is now open source. They can both be embedded in Delphi applications to create stand-alone executables with full database functionality.

Oracle Berkeley DB

As the name implies, Oracle’s embedded database is actually Berkeley DB, which Oracle acquired from Sleepycat Software and was originally developed at the University of California. Berkeley DB is a fast, open-source embedded database and is used in several well-known open-source products, including the Linux and BSD Unix operating systems, Apache Web server, OpenLDAP directory, and OpenOffice productivity suite.

Raima Database Manager

Raima Database Manager, also known as RDM, was one of the first database management systems to be categorized as an “embedded database” when it made its debut in 1984 under the name db vista. Since its initial release RDM has been continually evolving and in 1993 a client/server version of the database was introduced into the market under the product name Velocis. It has been estimated that since its initial release RDM has been used by an estimated 20,000 developers and deployed in over 25 million embedded systems and devices worldwide. Today these two products are developed and marketed by Raima Inc. under the product name RDM Embedded and RDM Server.

ScimoreDB

Scimore is an embedded database running on Windows. It performs fast and can easily handle millions of rows. This database provides full data reliability (ACID properties), manages heavy loads and includes features such as support for T-SQL, Read/Merge replication with ScimoreDB server, Full text search. Clients can access database via .NET provider or C++ library.

SolidDB

IBM’s SolidDB is another embedded database bought by a large technology company. Originally owned by Solid Information Technology, SolidDB was acquired in January 2008 by IBM. SolidDB is a hybrid disk/in-memory, relational database and is historically used as an embedded system database in telecommunications equipment, network software, and similar systems.

SQLite

SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is the most widely deployed SQL database engine in the world. The source code for SQLite is in the public domain. Includes both a native C library and a simple command line client for its database. It is embedded in the Google Android smart phone operating system, which itself is written in and supports Java, however, it appears to be native code.

SQL Server Compact

Microsoft’s SQL Server Compact is an embedded database with wide variety of features like multi-process connections, T-SQL, ADO.NET Sync Services to sync with any back end database, Merge Replication with SQL Server, Programming API: LINQ to SQL, LINQ to Entities, ADO.NET. The product runs on both Desktop and Mobile Windows platforms. It has been in the market for long time, used by many enterprises in production software ([http://www.microsoft.com/sql/prodinfo/casestudies/cs-mobile.mspx Case Studies]). The product went through multiple re-brandings and was known with multiple names like: SQL CE, SQL Server CE, SQL Server Mobile, SQL Mobile.

Valentina DB

Paradigma Software Valentina DB is an embedded SQL database with wide variety of features, including broad support for native implementations on Windows, Linux and Mac OS X. It is available as a local engine for over 18 platforms. Developers can also use VDN to deploy a royalty free Embedded Server on Windows, Linux and Mac OS X, which also natively supports PHP and Ruby-on-Rails server side scripting.

VistaDB

VistaDB is an embedded SQL database written entirely in C# and supports a number of features to make it compatible with SQL Server like T-SQL datatypes and syntax. The product runs on .Net platforms, including Mono. It has been in the market since 2004, and is used by many companies ([http://vistadb.net/customers.aspx Customer List]).

VistaDB as a company will cease to exist as of August 1, 2010.

Adapted from the Wikipedia article Embedded database, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Library

The academy’s library is the main source of books, periodicals and other study materials for all students during their courses. It function from 8.00 a.m. to 8.00 p.m. on all working days.

Area of the library is 800 m2 and is fully automated and centrally air conditioned.

The library operates a fully computerized information system with bar coding of books, periodicals. There are 28883 books, 16648 titles, 850 back volumes, 250 journals & magazines.

It also facilitates with user friendly online enquiry system, separate section for text & reference books, periodicals & journals and digital library. Other services provided are inter library loan, reprographic facility, book bank, delnet, department libraries and Internet service.

Member of INDEST- AICTE consortium, E-Journals for IEEE / IEL, ASME,ASCE,DEL.

DELNET is available for accessing various journals, articles and periodicals in science and technology. Abstracts are also provided for some articles. The database is comprehensive and up to date. Users requiring copies of journals, articles from different libraries can be brought through the librarian.

—-

Computing facilities

The college has two computer laboratories equipped with more than 798 systems all Pentium IV and Core 2 Duo along with a full fledged multimedia facility. Modern operating systems like Unix, Linux, Netware and Solaris are available. Important programming language compilers and application packages are also available on different platforms. There is a well-configured internet bro

—-

Transportation

There is a frequent transportation facility to the college by public service buses from Coimbatore, Tirupur and other surrounding places. In order to facilitate easy access to the college, the college runs twelve buses for students and staff from Coimbatore, Tirupur, Negamam and Palladam.

—-

On-Campus Student Residence Facility

A spacious modernized on campus halls of Residence for Men and Women students are available separately with all basic amenities. The Residence are highly conducive for academic pursuit and comfortable living. Men’s Residence can accommodate 500 students and Women’s residence can accommodate 200 students. Each room is furnished with cots, study tables and storage racks.

There is a separate block especially to accommodate the First year students. Visiting doctors take care of the health problems of the inmates.

—-

Other Amenities

** Vidhya Ganapathy temple

** Stores for Stationery and other needs

** Cafeteria and Snack bar

** Water purifiers in all blocks

** Installation of water treatment plant in the hostel (RO System)

Adapted from the Wikipedia article Tamilnadu College of Engineering, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

Ghost 3.1

The first versions of Ghost supported only the cloning of entire disks, however version 3.1 in 1997 allowed the cloning of individual partitions. Ghost could clone a disk or partition to another disk or partition or to an image file. Ghost allowed for writing a clone or image to a second disk in the same machine, another machine linked by a parallel or network cable, a network drive, or to a tape drive.

Ghost 4.0 and 4.1

Version 4.0 of Ghost added multicast technology, following the lead of a competitor, ImageCast. Multicasting allows sending a single backup image simultaneously to other machines without putting greater stress on the network than by sending an image to a single machine. This version also introduced Ghost Explorer, a Windows program which allowed a user to browse the contents of an image file and extract individual files from it. Explorer was subsequently enhanced to allow users to add and delete files on FAT, later on ext2, ext3 and NTFS filesystems in an image. Until 2007, Ghost Explorer could extract files from NTFS images but not edit NTFS images. Ghost Explorer could work with images from older versions but only slowly; version 4 images contained indexes to find files rapidly. Version 4.0 also moved from real-mode DOS to 286 protected-mode. The additional memory available allowed Ghost to provide several levels of compression for images, and to provide the file browser. In 1998, Ghost 4.1 allowed for password-protected images.

Ghost 5.0

Version 5.0 moved to 386 protected mode. Unlike the character-based user interface of

Ghost for NetWare

There was also a Norton Ghost version (called 2.0) for Novell NetWare around 1999, with supported NSS partitions (although it ran in DOS, like the others).

Ghost 6.0 (Ghost 2001)

Ghost 6.0 included a Console application in 2000 to simplify the management of large numbers of machines. The Console communicates with client software on managed computers to allow a system administrator to refresh the disk of a machine remotely.

As a DOS-based program, Ghost required machines running Windows to reboot to a DOS environment to run it. Ghost 6.0 required a separate DOS partition when used with the Console.

Ghost 7.0 / Ghost 2002

Released March 31, 2001

Norton Ghost version 7.0 (retail) was marketed as Norton Ghost 2002 Personal Edition. Help|About reveals version 7.00.

Ghost 7.5

Released December 14, 2001

Ghost 7.5 in 2002 created a ‘Virtual Partition’ instead – a DOS partition which actually exists as a file within a normal Windows filesystem. This significantly eased systems management. Ghost 7.5 could also write images to CD-R drives, and later versions can also write DVDs.

Ghost 8.0

Ghost 8.0 includes a standalone executable (filename: ghost32.exe) that runs directly from Windows, without the need to reboot. It is very well-suited for placement on bootable media, such as BartPE’s bootable CD. The Corporate edition supports Unicast, Multicast and peer-to-peer transfers via TCP/IP. Ghost 8.0 also allows an image to be saved on, or read from, an NTFS filesystem, although NTFS is not normally accessible from a DOS program.

Norton Ghost 2003

Norton Ghost 2003, a consumer edition of Ghost, was released on September 6, 2002. Available as an independent product, Norton Ghost 2003 was also included as a component of Norton SystemWorks 2003 Professional. A simpler, non-corporate version of Ghost, Norton Ghost 2003 does not include the Console but has a Windows front-end to script Ghost operations and create a bootable Ghost diskette (third-party CD burning software can be used to create a bootable Ghost CD based on a bootable Ghost diskette). The machine still needs to reboot to the Virtual Partition, but the user doesn’t need to interact with DOS. Symantec deprecated LiveUpdate support for Norton Ghost 2003 in early 2006. Two Symantec knowledge base articles ([http://service1.symantec.com/SUPPORT/ghost.nsf/docid/2002102509582825 Updates to Norton Ghost 2003] [http://service1.symantec.com/Support/sharedtech.nsf/docid/2007010219171513 How to obtain the programs updates that are archived on Symantec LiveUpdate server]) provide step-by-step instructions detailing how to obtain Norton Ghost 2003 updates from the LiveUpdate Archive. As of April 24, 2008, the latest version available from the archive is 2003.793. Older versions of Norton Ghost 2003 can be also updated from a system with a newer version of Norton Ghost 2003 by copying program directory from newer to older. Reliable support for SATA drives was also provided in 2003.793.

Ghost Solution Suite 1.0 (AKA Ghost 8.2)

In 2004, Symantec renamed the Enterprise version of Ghost to ”Symantec Ghost Solution Suite 1.0”. This helped to clarify the difference between the consumer and business lines of the product. This was further defined in February 2006, with the Release of Norton Save And Restore (some packages are labelled ”Norton Backup And Restore”), a standalone backup application based on Ghost 10.0.

Released November 15, 2004

Ghost Solution Suite 1.1 (Ghost 8.3)

Ghost Solution Suite 1.1 was released December 2005. Some of the new features include the ability to create an image file that is larger than 2 GB (in Ghost 8.2 or earlier versions, such image files are automatically split into two or more segments, so that each segment has a maximum size of 2 GB), more comprehensive manufacturing tools, and the ability to create a universal boot disk. Ghost Solution Suite is a bundle of an updated version of Ghost, Symantec Client Migration (a user data and settings migration tool) and the former PowerQuest equivalent, DeployCenter (using PQI images).

Ghost 9.0 (includes Ghost 2003)

Ghost 9.0 was released August 2, 2004. It represents a significant shift in the consumer product line from Ghost 2003, in several ways:

* It uses a totally different code base, based on the DriveImage product via Symantec’s acquisition of PowerQuest.

* The main product is a Windows-based application that must be installed on the target system.

* Images of the system can be made while Windows is running, rather than only when booted directly into DOS-mode Ghost.

* Incremental images (containing only changes since the last image) are supported.

* The Windows application requires Product Activation in order to function fully.

* The bootable environment on the Ghost 9 CD is only useful for recovery of existing backups – it cannot be used to create new images.

Since the DriveImage-based Ghost 9 did not support the older .gho format disk images, a separate CD containing Ghost 2003 was included in the retail packaging for users needing to access those older images.

The limitations of Ghost 9 compared to Ghost 2003 were not well communicated by Symantec, and resulted in many dissatisfied customers who purchased Ghost 9 expecting the previous version’s features (like making images from the bootable Ghost environment, no installation required, and no product activation).

Ghost 10.0

Supported media CDR/RW and DVD+-R/RW drives, USB and FireWire (IEEE 1394) devices, and Iomega Zip and Jaz drives. Enables the encryption of backups and support for Maxtor external drives with Maxtor OneTouch buttons.

The Ghost version 10.0 are compatible with previous revisions, but not with future revisions.

Norton Save And Restore 1.0 (Ghost 10.0)

Norton Save And Restore 1.0, released February 2006, was the renamed consumer version of Ghost. The system utilized Ghost 10.0′s engine, with the addition of features to allow backup and restoration of individual files.

Ghost Solution Suite 2.0 (Ghost 11.0)

Ghost Solution Suite 2.0 was released in November 2006. This version provides significant improvements in performance, as well as the ability to edit NTFS images. This version also adds support for Windows Vista, x64 versions of Windows, and GUID Partition Table (GPT)-based disks (although the software does not yet fully support systems with Extensible Firmware Interface (EFI)-compliant firmware). Running Live Update from Ghost Explorer will update Ghost to 11.0.2.1573.

Ghost 12.0

Ghost 12.0 includes Windows Vista support with an updated and more thorough user interface. It allows for a full system backup & one where individual files or folders can be selected & backed up.

This version also provides a “LightsOut Restore” feature. This restores a system with an on-disk software recovery environment, thereby allowing a recovery without a bootable CD. Upon boot-up of the computer a screen will ask which drive to boot from, the regular drive, or the LightsOut restore virtual drive.

LightsOut restore augments the ISO disk, which comes with the Ghost program, that has to be copied to a CD. This contains a recovery environment that allows one to recover files even if Windows doesn’t start up, but the computer can turn on. The latest update to the program is 12.0.5.29804.

Norton Save & Restore 2.0 (Ghost 13.0)

NSR 2.0 has fewer features when compared to Norton Ghost 12. NSR 2.0 offers one-time backups, file and folder backup, simplified schedule editor, Maxtor OneTouch integration and modifiable Symantec recovery disc.

This version also supports 32-bit and 64-bit versions of Windows XP and Vista.

Norton Ghost 14.0

Adapted from the Wikipedia article Ghost (software), under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

REXX was designed and first implemented, in assembly language, as an ‘own-time’ project between 20 March 1979 and mid-1982 by Mike Cowlishaw of IBM, originally as a scripting programming language to replace the languages EXEC and EXEC 2. It was designed to be a macro or scripting language for any system. As such, REXX is considered a precursor to Tcl and Python. Rexx was also intended by its creator to be a simplified and easier to learn version of the PL/I programming language.

It was first described in public at the SHARE 56 conference in Houston, Texas, in 1981, where customer reaction, championed by Ted Johnston of SLAC, led to it being shipped as an IBM product in 1982.

Over the years IBM included REXX in almost all of its operating systems (VM/CMS, VM/GCS, MVS TSO/E, AS/400, VSE/ESA, AIX, CICS/ESA, PC-DOS, and OS/2), and has made versions available for Novell NetWare, Windows, Java, and Linux.

The first non-IBM version was written for PC-DOS by Charles Daney in 1984/5. The first compiler version appeared in 1987, written for CMS by Lundin and Woodruff. Other versions have also been developed for Atari, AmigaOS, Unix (many variants), Solaris, DEC, Windows, Windows CE, Pocket PC, DOS, Palm OS, QNX, OS/2, Linux, BeOS, EPOC32, AtheOS, OpenVMS, OpenEdition, Macintosh, and Mac OS X.

The Amiga version of REXX, called ARexx was included with AmigaOS 2 onwards and was popular for scripting as well as application control. Many Amiga applications have an “ARexx port” built into them which allows control of the application from Rexx. One single Rexx

Several freeware versions of REXX are available. In 1992, the two most widely-used open-source ports appeared: Ian Collier’s REXX/imc for Unix and Anders Christensen’s Regina (later adopted by Mark Hessling) for Windows and Linux. BREXX is well-known for WinCE and Pocket PC platforms.

OS/2 had a visual development system from Watcom VX-REXX another dialect was VisPro REXX from Hockware.

In 1996 ANSI published a standard for REXX:

ANSI X3.274–1996 “Information Technology – Programming Language REXX”. More than two dozen books on REXX have been published since 1985.

Since the mid-1990s, two newer variants of REXX have appeared:

*NetRexx — which compiles to Java byte-code via Java source code; this has no reserved keywords at all, and uses the Java object model, and is therefore not generally upwards-compatible with ‘classic’ REXX.

*Object REXX — which is an object-oriented generally upwards-compatible version of REXX.

In 1990, Cathy Dager of SLAC organized the first independent REXX symposium, which led to the forming of the REXX Language Association. Symposia are held annually.

REXX marked its 25th anniversary on 20 March 2004, which was celebrated at the REXX Language Association’s 15th International REXX Symposium in Böblingen, Germany, in May 2004.

On October 12, 2004, IBM announced their plan to release their Object REXX implementation under the Common Public License. Recent releases of Object Rexx contain a ActiveX WSH scripting engine implementing this version of the Rexx language.

On February 22, 2005, the first public release of Open Object Rexx (ooRexx) was announced. This product contains a WSH scripting engine which allows for programming of the Windows operating system and applications with Rexx in the same fashion in which Visual Basic and Java/J++ are implemented by the default WSH installation and Perl, Tcl, Python third-party scripting engines. The default filename extension for ooRexxScript scripts is *.rxs.

A command-line Rexx interpreter is also installed with ooRexx, and it is also possible to run ooRexxScript programmes from the command line by means of the CScript command (WScript may also be run from the command line) invoking the Windows Scripting Host.

A Rexx IDE, RxxxEd, has been developed for Windows. RxSock for network communication as well as other add-ons to and implementations of Regina Rexx have been developed, and a Rexx interpreter for the Windows command line is supplied in most Resource Kits for various versions of Windows and works under all of them as well as MS-DOS.

Portable Rexx by Kilowat and Personal Rexx by Quercus are two Rexx interpreters designed for MS-DOS and can of course be run under Windows as well using a command prompt.

Spelling

Originally it was just called “Rex”, “A Reformed EXecutor”; the extra “X” was added to avoid collisions with other products’ names. The expansion of Rexx to the REstructured EXtended EXecutor is believed to be a backronym. REX was originally all uppercase because the mainframe code was uppercase oriented. The ”style” in those days was to have all-caps names (partly because almost all code was still all-caps then). For the product it became REXX, and both editions of Mike Cowlishaw’s book use all-caps. By the 1990s it was largely written Rexx or, with small caps: REXX. As of 2008, Mike Cowlishaw seems to prefer Rexx, IBM documents use REXX, and the ANSI standard uses REXX.

Adapted from the Wikipedia article REXX, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.

WarXing is done through the use of specific computer programs and hardware. The software used is usually Network discovery software, yet may also include RF monitor software, and GPS-logging programs, to aid the hacker with finding the exact position of wireless networks, and mapping them with GPS-information. Before commencing on warXing-trips, the user must always make sure he unbinds his NIC. This needs to be done to disable all communication towards APs (reception of packets remains however unchanged). The best approach to do this is to disable all network protocols (TCP/IP, Netware, NetBEUI, etc.). By disabling communication towards APs, any possible legal problems are avoided and another practical problem is avoided as well. This practical problem is that autoconnection may automatically place the SSID in the wireless adapter operating profile, halting your ability of logging any additional stations encountered later-on. Unbinding the NIC can be done with the command:

* ipconfig /release_all (in windows; command prompt)

* ip link set dev ”interface-name” down

or by disabling the TCP/IP protocol in “Network Connections” (for Windows XP)

Popular software

For warXing, people may opt to install the software required separately or immediately install purpose-built OSs (Linux-variants) which have all warXing tools already installed and are even sometimes able to run as a Live CD. These Linux OSs are BackTrack, WarLinux and Auditor. The purpose-built OSs also feature other tools to crack protected wireless networks and analyze the sys

Separate software can be installed on regular operating systems such as Mac OS X, Linux or Windows. Often, a single network discovery software program as NetStumbler (windows, desktop), MiniStumbler (windows CE, handheld), KisMAC (desktop, Macintosh) or Kismet (Linux, desktop) is all which most people install. Network discovery software is used to discover and map out the open (as well as protected) WLANs in the area. WLANs which have the SSID broadcasting turned off require a passive scanner such as Kismet.

GPS-mapping software sometimes installed alongside includes Stumbverter and MapPoint. Netstumbler already records the GPS-information, yet does not place them on a map, which is why these programs are often added. However, MapPoint (a Microsoft product) is not free, and is thus often not an option for certain people. To suit this target group, a free alternative has been made called DiGLE. Also, [http://www.wifimaps.com/ WiFimaps] offers some utilities.

Finally, some people also want to use the network information obtained through the network discovery software (and other tools such as packet analyzers) to also hack the network. This activity, which is no longer considered warXing, may allow the hacker significant advantages. Hacking protected networks may allow Piggybacking or using the network as a “zombie”, meaning using the connection to hack other PCs/networks and letting someone else look like the bad guy. Also, instead of hacking it, hackers may also decide to jam the network. RF-jamming can be done through RF generators (e.g. from HP, Anritsu) or Power signal generators (e.g. from Terabeam Wireless, Global Gadget or Tektronix). Jamming (as well as Queensland and DoS-attacks) of course does not usually provide any advantage for the hacker, and is often done for retribution purposes.

How-to documents

Practical how-to information is available from documents as “The Definitive Guide to Wireless WarXing” , “WarDriving HOWTO”, “Wireless LAN resources for Linux”, “Official Wireless Howto” , etc. More info may be gathered from books as “Hacking Wireless Networks for Dummies”, which have sections about wardriving.

Adapted from the Wikipedia article WarXing, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki

No related posts.