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MS-DOS 7.0
MS-DOS 7 is a real mode operating system for IBM PC compatibles. Unlike earlier versions of MS-DOS it was not released separately by Microsoft, but included in the Windows 9x family of operating systems. Windows 95 RTM reports to be MS-DOS 7.0, while Windows 95 OSR 2.x and Windows 98 report as 7.1. Windows 9x runs under DOS similar to Windows 3.1x, and while according to Microsoft the role of MS-DOS was reduced to a boot loader and acted as the 16-bit legacy device driver layer, it has been stated that there is almost no difference in the relationship between Windows 9x and its included MS-DOS 7.x and Windows 3.x and MS-DOS 6.x. New features As the first version in the series, MS-DOS 7.0 added support for long filename (LFN) awareness, and its DIR command for example will show them with an LFN driver such as DOSLFN (earlier versions of MS-DOS wouldn’t show long filenames even with such a driver). It also supports for larger extended memory (up to 4GB) via its HIMEM.SYS driver. V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Command and control (abbr. C2) is a "set of organizational and technical attributes and processes ... hatemploys human, physical, and information resources to solve problems and accomplish missions" to achieve the goals of an organization o ..., the exercise of authority in a military organization * Command hierarchy, a group of people dedicated to carrying out orders "from the top" Mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Release To Manufacture
A software release life cycle is the sum of the stages of development and maturity for a piece of computer software ranging from its initial development to its eventual release, and including updated versions of the released version to help improve the software or fix software bugs still present in the software. There are several models for such a life cycle. A common method is that suggested by Microsoft, which divides software development into five phases: Pre-alpha, Alpha, Beta, Release candidate, and Stable. Pre-alpha refers to all activities performed during the software project before formal testing. The alpha phase generally begins when the software is feature complete but likely to contain several known or unknown bugs. The beta phase generally begins when the software is deemed feature complete, yet likely to contain several known or unknown bugs. Software in the production phase will generally have many more bugs in it than completed software, as well as speed/performan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Year 2000 Problem
The year 2000 problem, also known as the Y2K problem, Y2K scare, millennium bug, Y2K bug, Y2K glitch, Y2K error, or simply Y2K refers to potential computer errors related to the formatting and storage of calendar data for dates in and after the year 2000. Many programs represented four-digit years with only the final two digits, making the year 2000 indistinguishable from 1900. Computer systems' inability to distinguish dates correctly had the potential to bring down worldwide infrastructures for industries ranging from banking to air travel. In the years leading up to the turn of the century (millennium), the public gradually became aware of the "Y2K scare", and individual companies predicted the global damage caused by the bug would require anything between $400 million and $600 billion to rectify. A lack of clarity regarding the potential dangers of the bug led some to stock up on food, water, and firearms, purchase backup generators, and withdraw large sums of money in an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder-head-sector
Cylinder-head-sector (CHS) is an early method for giving addresses to each physical block of data on a hard disk drive. It is a 3D-coordinate system made out of a vertical coordinate ''head'', a horizontal (or radial) coordinate ''cylinder'', and an angular coordinate ''sector''. Head selects a circular surface: a platter in the disk (and one of its two sides). Cylinder is a cylindrical intersection through the stack of platters in a disk, centered around the disk's spindle. Combined, cylinder and head intersect to a circular line, or more precisely: a circular strip of physical data blocks called ''track''. Sector finally selects which data block in this track is to be addressed, as the track is subdivided into several equally-sized portions, each of which is an arc of (360/n) degrees, where n is the number of sectors in the track. CHS addresses were exposed, instead of simple linear addresses (going from ''0'' to the ''total block count on disk - 1''), because early hard drive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logical Block Addressing
Logical block addressing (LBA) is a common scheme used for specifying the location of blocks of data stored on computer storage devices, generally secondary storage systems such as hard disk drives. LBA is a particularly simple linear addressing scheme; blocks are located by an integer index, with the first block being LBA 0, the second LBA 1, and so on. The IDE standard included 22-bit LBA as an option, which was further extended to 28-bit with the release of ATA-1 (1994) and to 48-bit with the release of ATA-6 (2003), whereas the size of entries in on-disk and in-memory data structures holding the address is typically 32 or 64 bits. Most hard disk drives released after 1996 implement logical block addressing. Overview In logical block addressing, only one number is used to address data, and each linear base address describes a single block. The LBA scheme replaces earlier schemes which exposed the physical details of the storage device to the software of the operating s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Concep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environment Variable
An environment variable is a dynamic-named value that can affect the way running processes will behave on a computer. They are part of the environment in which a process runs. For example, a running process can query the value of the TEMP environment variable to discover a suitable location to store temporary files, or the HOME or USERPROFILE variable to find the directory structure owned by the user running the process. They were introduced in their modern form in 1979 with Version 7 Unix, so are included in all Unix operating system flavors and variants from that point onward including Linux and macOS. From PC DOS 2.0 in 1982, all succeeding Microsoft operating systems, including Microsoft Windows, and OS/2 also have included them as a feature, although with somewhat different syntax, usage and standard variable names. Design In all Unix and Unix-like systems, as well as on Windows, each process has its own separate set of environment variables. By default, when a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS Kernel
IBMDOS.COM is the filename of the DOS kernel. Loaded and initially invoked by the DOS BIOS in IBMBIO.COM during the boot process, it contains the hardware-independent parts of the operating system, including the embedded FAT12, FAT16 and, in newer versions, the FAT32 file system code, as well as the code to provide the DOS API to applications. The file exists in PC DOS 1.0 to 7.10 and DR DOS 5.0 and higher (except for DR-DOS 7.06), with MS-DOS using MSDOS.SYS (from version 1.10 to 6.22) for the same purpose. DR DOS 3.31 to 3.41 used the equivalent DRBDOS.SYS file instead. (For compatibility purposes with some DOS applications the IBMDOS.COM file name was briefly also used by the IBM version of OS/2 1.0, where it resembled the OS2DOS.COM OS/2 kernel file as used by Microsoft.) By default, the file is located in the root directory of the bootable drive/partition (normally C:\) and has the ''hidden'', ''read-only'', and ''system'' file attributes set. As IBMDOS.C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Memory Area
In DOS memory management, the upper memory area (UMA) refers to memory between the addresses of 640 KB and 1024 KB ( 0xA0000–0xFFFFF) in an IBM PC or compatible. IBM reserved the uppermost 384 KB of the 8088 CPU's 1024 KB address space for BIOS ROM, Video BIOS, Option ROMs, video RAM, RAM on peripherals, memory-mapped I/O, and obsoleted ROM BASIC. However, even with video RAM, the ROM BIOS, the Video BIOS, the Option ROMs, and I/O ports for peripherals, much of this 384 KB of address space was unused. As the 640 KB memory restriction became ever more of an obstacle, techniques were found to fill the empty areas with RAM. These areas were referred to as upper memory blocks (UMBs). Usage The next stage in the evolution of DOS was for the operating system to use upper memory blocks (UMBs) and the high memory area (HMA). This occurred with the release of DR DOS 5.0 in 1990. DR DOS' built-in memory manager, EMM386.EXE, could perf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS Command
This article presents a list of commands used by DOS operating systems, especially as used on x86-based IBM PC compatibles (PCs). Other DOS operating systems are not part of the scope of this list. In DOS, many standard system commands were provided for common tasks such as listing files on a disk or moving files. Some commands were built into the command interpreter, others existed as external commands on disk. Over the several generations of DOS, commands were added for the additional functions of the operating system. In the current Microsoft Windows operating system, a text-mode command prompt window, cmd.exe, can still be used. Command processing The command interpreter for DOS runs when no application programs are running. When an application exits, if the transient portion of the command interpreter in memory was overwritten, DOS will reload it from disk. Some commands are internal—built into COMMAND.COM; others are external commands stored on disk. When the user ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HIMEM
HIMEM.SYS is a DOS device driver which allows DOS programs to store data in extended memory according to the Extended Memory Specification (XMS). The memory beyond the first 1 MB of address space is required by Windows 9x/ Me in order to load; therefore, these versions of Microsoft Windows require HIMEM.SYS to be loaded to be able to run. HIMEM.SYS was first included with Windows 2.1 (1988). In MS-DOS 5.0 (1991) and later, HIMEM.SYS can be used to load the DOS kernel code into the High Memory Area (HMA) to increase the amount of available conventional memory by specifying DOS=HIGH in CONFIG.SYS. In DR DOS 5.0 (1990) and 6.0 (1991), the driver is named HIDOS.SYS rather than HIMEM.SYS, like the corresponding DCONFIG.SYS or CONFIG.SYS directive HIDOS=ON. In FreeDOS, the matching file is named HIMEM.EXE and can be loaded from the FreeDOS configuration file named FDCONFIG.SYS or CONFIG.SYS. In Windows 3.1 and Windows 9x, there is also a command-line loadable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extended Memory
In DOS memory management, extended memory refers to memory above the first megabyte (220 bytes) of address space in an IBM PC or compatible with an 80286 or later processor. The term is mainly used under the DOS and Windows operating systems. DOS programs, running in real mode or virtual x86 mode, cannot directly access this memory, but are able to do so through an application programming interface called the ''Extended Memory Specification'' (XMS). This API is implemented by a driver (such as HIMEM.SYS) or the operating system, which takes care of memory management and copying memory between conventional and extended memory, by temporarily switching the processor into protected mode. In this context, the term "extended memory" may refer to either the whole of the extended memory or only the portion available through this API. Extended memory can also be accessed directly by DOS programs running in protected mode using VCPI or DPMI, two (different and incompatible) method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
