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DRVSPACE.INI
DriveSpace (initially known as DoubleSpace) is a disk compression utility supplied with MS-DOS starting from MS-DOS 6.0, version 6.0 in 1993 and ending in 2000 with the release of Windows Me. The purpose of DriveSpace is to increase the amount of data the user could store on disks by transparently compressing and decompressing data on-the-fly. It is primarily intended for use with hard disk, hard drives, but use for floppy disks is also supported. This feature was removed in Windows XP and later. Overview In the most common usage scenario, the user would have one hard drive in the computer, with all the space allocated to one disk partition, partition (usually as Drive letter, drive C:). The software would compress the entire partition contents into one large file in the root directory. On booting the system, the driver would allocate this large file as drive C:, enabling files to be accessed as normal. Microsoft's decision to add disk compression to MS-DOS 6.0 was influence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DoubleDisk
A disk compression software utility increases the amount of information that can be stored on a hard disk drive of given size. Unlike a file compression utility, which compresses only specified files—and which requires the user to designate the files to be compressed—an on-the-fly disk compression utility works automatically through resident software without the user needing to be aware of its existence. On-the-fly disk compression is therefore also known as transparent, real-time or online disk compression. When information needs to be stored to the hard disk, the utility compresses the information. When information needs to be read, the utility decompresses the information. A disk compression utility overrides the standard operating system routines. Since all software applications access the hard disk using these routines, they continue to work after disk compression has been installed. Disk compression utilities were popular especially in the early 1990s, when microco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Tools For DoubleSpace
Double Tools for DoubleSpace is a software utility released in 1993 by the Menlo Park-based company Addstor, Inc. The utility functioned as an add-on to the disk compression software DoubleSpace, supplied with MS-DOS 6.0, adding a number of features not available in the standard version. Features Most of the Double Tools utilities worked from Microsoft Windows, providing a graphical view and control panel of the compressed drives on the computer (the utilities supplied with MS-DOS only operated from DOS-mode). Double Tools also contained a number of disk checking and rescue/recovery utilities. Some of the included utilities were called ''Silent Tools''. One of the unique features of its time was the capability to defragment a DoubleSpace compressed drive in the background. Some of the features, including the background defragmentation capability, required the user to let Double Tools replace the standard compression driver for MS-DOS (DBLSPACE.BIN) with one developed by Addst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shutdown (computing)
To shut down or power off a computer is to switch, remove power from a computer's main components in a controlled way. After a computer is shut down, main components such as Central processing unit, CPUs, Random-access memory, RAM modules and hard disk drives are powered down, although some internal components, such as an internal clock, may retain power. Implementations The shutdown feature and command (computing), command is available in Microsoft Microsoft Windows, Windows, ReactOS, Hewlett-Packard, HP HP Multi-Programming Executive, MPE/iX, and in a number of Unix and Unix-like operating systems such as Apple Inc., Apple macOS. Microsoft Windows and ReactOS In Microsoft Windows and ReactOS, a PC or server is shut down by selecting the item from the Start menu on the desktop. Options include shutting down the system and powering off, automatically restarting the system after shutting down, or putting the system into standby mode, stand-by mode. Just like other operatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMARTDRV
SmartDrive (or SMARTDRV) is a disk caching program shipped with MS-DOS versions 4.01 through 6.22 and Windows 3.0 through Windows 3.11. It improves data transfer rates by storing frequently accessed data in random-access memory (RAM). Early versions of SmartDrive were loaded through a device driver named . Versions 4.0 and later were loaded through an executable file named , which could be run at user's discretion or at boot time via . However, also includes a double-buffering driver that should be loaded through . Version 4.0 also introduced 32-bit disk access and could reduce its footprint in conventional memory (the first 640 kilobytes of memory which was critical to DOS) by running in upper memory area (the 384 kilobytes of memory located beyond the conventional memory). A cloaked variant of SmartDrive utilizing the Helix Cloaking API was available from Helix Software. On Intel 80386 processors, it could run in protected mode to reduce its footprint in conventional m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real Mode
Real mode, also called real address mode, is an operating mode of all x86-compatible CPUs. The mode gets its name from the fact that addresses in real mode always correspond to real locations in memory. Real mode is characterized by a 20- bit segmented memory address space (giving 1 MB of addressable memory) and unlimited direct software access to all addressable memory, I/O addresses and peripheral hardware. Real mode provides no support for memory protection, multitasking, or code privilege levels. Before the introduction of protected mode with the release of the 80286, real mode was the only available mode for x86 CPUs; and for backward compatibility, all x86 CPUs start in real mode when reset, though it is possible to emulate real mode on other systems when starting in other modes. History The 80286 architecture introduced protected mode, allowing for (among other things) hardware-level memory protection. Using these new features, however, required a new operating system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Protection
Memory protection is a way to control memory access rights on a computer, and is a part of most modern instruction set architectures and operating systems. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself. Protection may encompass all accesses to a specified area of memory, write accesses, or attempts to execute the contents of the area. An attempt to access unauthorized memory results in a hardware fault, e.g., a segmentation fault, storage violation exception, generally causing abnormal termination of the offending process. Memory protection for computer security includes additional techniques such as address space layout randomization and executable-space protection. Methods Segmentation Segmentation refers to dividing a computer's memory into segments. A reference to a memory locatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Sector
In computer disk storage, a sector is a subdivision of a track on a magnetic disk or optical disc. For most disks, each sector stores a fixed amount of user-accessible data, traditionally 512 bytes for hard disk drives (HDDs), and 2048 bytes for CD-ROMs, DVD-ROMs and BD-ROMs. Newer HDDs and SSDs use 4096 byte (4 KiB) sectors, which are known as the Advanced Format (AF). The sector is the minimum storage unit of a hard drive. Most disk partitioning schemes are designed to have files occupy an integral number of sectors regardless of the file's actual size. Files that do not fill a whole sector will have the remainder of their last sector filled with zeroes. In practice, operating systems typically operate on blocks of data, which may span multiple sectors. Geometrically, the word sector means a portion of a disk between a center, two radii and a corresponding arc (see Figure 1, item B), which is shaped like a slice of a pie. Thus, the ''disk sector'' (Figure 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Fragmentation
In computing, file system fragmentation, sometimes called file system aging, is the tendency of a file system to lay out the contents of files non-continuously to allow in-place modification of their contents. It is a special case of data fragmentation. File system fragmentation negatively impacts seek time in spinning storage media, which is known to hinder throughput. Fragmentation can be remedied by re-organizing files and free space back into contiguous areas, a process called defragmentation. Solid-state drives do not physically seek, so their non-sequential data access is hundreds of times faster than moving drives, making fragmentation less of an issue. It is recommended to not manually defragment solid-state storage, because this can prematurely wear drives via unnecessary write–erase operations. Causes When a file system is first initialized on a partition, it contains only a few small internal structures and is otherwise one contiguous block of empty space. This me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Corruption
Data corruption refers to errors in computer data that occur during writing, reading, storage, transmission, or processing, which introduce unintended changes to the original data. Computer, transmission, and storage systems use a number of measures to provide end-to-end data integrity, or lack of errors. In general, when data corruption occurs, a Computer file, file containing that data will produce unexpected results when accessed by the system or the related application. Results could range from a minor loss of data to a system crash. For example, if a Document file format, document file is corrupted, when a person tries to open that file with a document editor they may get an error message, thus the file might not be opened or might open with some of the data corrupted (or in some cases, completely corrupted, leaving the document unintelligible). The adjacent image is a corrupted image file in which most of the information has been lost. Some types of malware may intentional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conventional Memory
In DOS memory management, conventional memory, also called base memory, is the first 640 kilobytes of the memory on IBM PC or compatible systems. It is the read-write memory directly addressable by the processor for use by the operating system and application programs. As memory prices rapidly declined, this design decision became a limitation in the use of large memory capacities until the introduction of operating systems and processors that made it irrelevant. 640 KB barrier The 640 KB barrier is an architectural limitation of IBM PC compatible PCs. The Intel 8088 CPU, used in the original IBM PC, was able to address 1 MB (220 bytes), since the chip offered 20 address lines. In the design of the PC, the memory below 640 KB was for random-access memory on the motherboard or on expansion boards, and it was called the conventional memory area. The first memory segment (64 KB) of the conventional memory area is named lower memory or low memory are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
