File Control Block
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File Control Block
A File Control Block (FCB) is a file system structure in which the state of an open file is maintained. A FCB is managed by the operating system, but it resides in the memory of the program that uses the file, not in operating system memory. This allows a process to have as many files open at one time as it wants, provided it can spare enough memory for an FCB per file. The FCB originates from CP/M and is also present in most variants of DOS, though only as a backwards compatibility measure in MS-DOS versions 2.0 and later. A full FCB is 36 bytes long; in early versions of CP/M, it was 33 bytes. This fixed size, which could not be increased without breaking application compatibility, led to the FCB's eventual demise as the standard method of accessing files. The meanings of several of the fields in the FCB differ between CP/M and DOS, and also depending on what operation is being performed. The following fields have consistent meanings: The 20-byte-long field starting at offset ...
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Computer File
A computer file is a computer resource for recording data in a computer storage device, primarily identified by its file name. Just as words can be written to paper, so can data be written to a computer file. Files can be shared with and transferred between computers and mobile devices via removable media, networks, or the Internet. Different types of computer files are designed for different purposes. A file may be designed to store an Image, a written message, a video, a computer program, or any wide variety of other kinds of data. Certain files can store multiple data types at once. By using computer programs, a person can open, read, change, save, and close a computer file. Computer files may be reopened, modified, and copied an arbitrary number of times. Files are typically organized in a file system, which tracks file locations on the disk and enables user access. Etymology The word "file" derives from the Latin ''filum'' ("a thread"). "File" was used in the conte ...
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FAT32
File Allocation Table (FAT) is a file system developed for personal computers. Originally developed in 1977 for use on floppy disks, it was adapted for use on hard disks and other devices. It is often supported for compatibility reasons by current operating systems for personal computers and many mobile devices and embedded systems, allowing interchange of data between disparate systems. The increase in disk drives capacity required three major variants: FAT12, FAT16 and FAT32. The FAT standard has also been expanded in other ways while generally preserving backward compatibility with existing software. FAT is no longer the default file system for Microsoft Windows computers. FAT file systems are still commonly found on floppy disks, flash and other solid-state memory cards and modules (including USB flash drives), as well as many portable and embedded devices. FAT is the standard file system for digital cameras per the DCF specification. Overview Concepts ...
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Novell DOS 7
DR-DOS (written as DR DOS, without a hyphen, in versions up to and including 6.0) is a disk operating system for IBM PC compatibles. Upon its introduction in 1988, it was the first DOS attempting to be compatible with IBM PC DOS and MS-DOS (which were the same product sold under different names). DR-DOS was developed by Gary A. Kildall's Digital Research and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86. As ownership changed, various later versions were produced with names including Novell DOS and Caldera OpenDOS. History Origins in CP/M Digital Research's original CP/M for the 8-bit Intel 8080- and Z-80-based systems spawned numerous spin-off versions, most notably CP/M-86 for the Intel 8086/8088 family of processors. Although CP/M had dominated the market since the mid-1970s, and was shipped with the vast majority of non-proprietary-architecture personal computers, the IBM PC in 1981 brought the beginning of what was eventually ...
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Addison Wesley Publishing Company
Addison-Wesley is an American publisher of textbooks and computer literature. It is an imprint of Pearson PLC, a global publishing and education company. In addition to publishing books, Addison-Wesley also distributes its technical titles through the O'Reilly Online Learning e-reference service. Addison-Wesley's majority of sales derive from the United States (55%) and Europe (22%). The Addison-Wesley Professional Imprint produces content including books, eBooks, and video for the professional IT worker including developers, programmers, managers, system administrators. Classic titles include ''The Art of Computer Programming'', ''The C++ Programming Language'', ''The Mythical Man-Month'', and ''Design Patterns''. History Lew Addison Cummings and Melbourne Wesley Cummings founded Addison-Wesley in 1942, with the first book published by Addison-Wesley being Massachusetts Institute of Technology professor Francis Weston Sears' ''Mechanics''. Its first computer book was ''Progra ...
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Microsoft Press
Microsoft Press is the publishing arm of Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ..., usually releasing books dealing with various current Microsoft technologies. Microsoft Press' first introduced books were ''The Apple Macintosh Book'' by Cary Lu and ''Exploring the IBM PCjr Home Computer'' by Peter Norton in 1984 at the West Coast Computer Faire. The publisher has gone on to release books by other recognizable authors such as Charles Petzold, Steve McConnell, Mark Russinovich and Jeffrey Richter. Following a deal signed in 2009, O'Reilly Media became the official distributor of Microsoft Press books. In 2014, the distributor was changed to Pearson PLC, Pearson. In July 2016, Microsoft Press editorial staff was laid off. References External links

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Record-oriented Filesystem
In computer science, a record-oriented filesystem is a file system where data is stored as collections of records. This is in contrast to a byte-oriented filesystem, where the data is treated as an unformatted stream of bytes. There are several different possible record formats; the details vary depending on the particular system. In general the formats can be fixed-length or variable length, with different physical organizations or padding mechanisms; metadata may be associated with the file records to define the record length, or the data may be part of the record. Different access methods for records may be provided, for example records may be retrieved in sequential order, by key, or by record number. Origin and characteristics Record-oriented filesystems are frequently associated with mainframe operating systems, such as OS/360 and successors and DOS/360 and successors, and midrange operating systems, such as RSX-11 and VMS. However, they originated earlier in so ...
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COMMAND
Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards * Command pattern, a software design pattern in which objects represent actions * Voice command, in speech recognition Military * Military command (instruction) or military order * Command responsibility, the doctrine of hierarchical accountability in cases of war crimes * Command (military formation), an organizational unit * Command and control, the exercise of authority in a military organization * Command hierarchy, a group of people dedicated to carrying out orders "from the top" Music * ''Command'' (album), a 2009 album by Client * Command Records, a record label Sports * Command (baseball), the ability of a pitcher to throw a pitch where he intends to * Kansas City Command, a former professional arena football team * Commands (hors ...
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DOSBox
DOSBox is a free and open-source emulator which runs software for MS-DOS compatible disk operating systems—primarily video games. It was first released in 2002, when DOS technology was becoming obsolete. Its adoption for running DOS games is widespread, with it being used in commercial re-releases of those games as well. DOSBox can be downloaded and used from the video game console emulator front-end RetroArch. Development Before Windows XP, consumer-oriented versions of Windows were based on MS-DOS. Windows 3.0 and its updates were operating environments that ran on top of MS-DOS, and the Windows 9x series consisted of operating systems that were still based on MS-DOS. These versions of Windows could run DOS applications. Conversely, the Windows NT operating systems were not based on DOS. A member of the series is Windows XP, which debuted on October 25, 2001, to become the first consumer-oriented version of Windows to not use DOS. Although Windows XP could emulate DO ...
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Windows 2000
Windows 2000 is a major release of the Windows NT operating system developed by Microsoft and oriented towards businesses. It was the direct successor to Windows NT 4.0, and was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on December 15, 1999, and was officially released to retail on February 17, 2000. It was Microsoft's business operating system until the introduction of Windows XP Professional in 2001. Windows 2000 introduced NTFS 3.0, Encrypting File System, as well as basic and dynamic disk storage. Support for people with disabilities was improved over Windows NT 4.0 with a number of new Assistive technology, assistive technologies, and Microsoft increased support for different languages and Locale (computer software), locale information. The Windows 2000 Server family has additional features, most notably the introduction of Active Directory, which in the years following became a widely used directory service in business environmen ...
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Windows NT
Windows NT is a proprietary graphical operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ... produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system. The first version of Windows NT was Windows NT 3.1 and was produced for workstations and server computers. It was a commercially focused operating system intended to complement consumer versions of Microsoft Windows, Windows that were based on MS-DOS (including Windows 1.0 through Windows 3.1x). Gradually, the Windows NT family was expanded into Microsoft's general-purpose operating system product line for all personal computers, deprecating the Windows 9x family. "NT" was formerly expanded to "New Technology" but no ...
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WordStar
WordStar is a word processor application for microcomputers. It was published by MicroPro International and originally written for the CP/M-80 operating system, and later written also for MS-DOS and other 16-bit PC OSes. Rob Barnaby was the sole author of the early versions of the program. Starting with WordStar 4.0, the program was built on new code written principally by Peter Mierau. WordStar dominated the market in the early and mid-1980s, succeeding the market leader Electric Pencil. WordStar was written with as few assumptions as possible about the operating system and machine hardware, allowing it to be easily ported across the many platforms that proliferated in the early 1980s. Because all of these versions had relatively similar commands and controls, users could move between platforms with equal ease. It was already popular when its inclusion with the Osborne 1 portable computer made the program the ''de facto'' standard for much of the small computer word-processing ...
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