Misplaced Pages

#658341

99-526: DOS/V is a Japanese computing initiative starting in 1990 to allow DOS on IBM PC compatibles with VGA cards to handle double-byte (DBCS) Japanese text via software alone. It was initially developed from PC DOS by IBM for its PS/55 machines (a localized version of the PS/2 ), but IBM gave the driver source code to Microsoft , who then licensed a DOS/V-compatible version of MS-DOS to other companies. Kanji fonts and other locale information are stored on

198-453: A 100% PC/AT compatible machine codenamed "JX2", but cancelled it in 1986. Masahiko Hatori ( 羽鳥 正彦 ) was a developer of JX's DOS. Through the development of JX, he learned the skills needed to localize an English computer into Japanese. In 1987, he started developing the DOS/V during spare time at IBM Yamato Development Laboratory . He thought the 480-line mode of VGA and a processor as fast as

297-483: A 64 KiB page frame in the reserved upper memory area. 80386 and later systems could use a virtual 8086 mode (V86) mode memory manager like EMM386 to create expanded memory from extended memory without the need of an add-on card. The second specification was the Extended Memory Specification (XMS) for 80286 and later systems. This provided a way to copy data to and from extended memory, access to

396-450: A DOS/V emulator that could run DOS/V applications on a VGA-equipped J-3100 computer. AST Research Japan and Sharp decided to bundle IBM DOS J5.0/V. Compaq developed own DOS/V drivers, and released their first DOS/V computers in April 1992. On 10 December 1993, Microsoft Japan and IBM Japan released new versions of DOS/V, MS-DOS 6.2/V Upgrade and PC DOS J6.1/V. Although both were released at

495-947: A DOS/V environment in NTVDM . It was removed in Windows Vista . PC DOS versions of DOS/V (J for Japanese, P for Chinese (PRC), T for Taiwanese, H for Korean (Hangul)): MS-DOS versions of DOS/V: DR DOS versions of DOS/V: IBM DOS/V Extension extends DOS/V drivers to set up a variety of text modes for certain video adapters. The High-quality Text Mode is the default 80 columns by 25 rows with 12×24 pixels large characters. The High-density Text Mode (Variable Text; V-Text) offers large text modes with various font sizes. DOS/V Extension V1.0 included drivers for VGA, XGA , PS/55 Display Adapter, SVGA (800×600) and ET4000 (1024×768). Some of its drivers were included in PC DOS J6.1/V and later. DOS DOS ( / d ɒ s / , / d ɔː s / )

594-401: A batch file is interpreted as a program to run. Batch files can also make use of internal commands, such as GOTO and conditional statements . The operating system offers an application programming interface that allows development of character-based applications, but not for accessing most of the hardware , such as graphics cards , printers , or mice . This required programmers to access

693-494: A configuration file similar to CONFIG.SYS and AUTOEXEC.BAT. If the MSDOS.SYS BootGUI directive is set to 0 , the boot process will stop with the command processor (typically COMMAND.COM) loaded, instead of executing WIN.COM automatically. DOS uses a filesystem which supports 8.3 filenames : 8 characters for the filename and 3 characters for the extension. Starting with DOS 2 hierarchical directories are supported. Each directory name

792-425: A conversation with fellow United Way National Board Executive Committee member Mary Maxwell Gates , who referred Opel to her son Bill Gates for help with an 8088-compatible build of CP/M. IBM was then sent to Digital Research, and a meeting was set up. However, initial negotiations for the use of CP/M broke down: Digital Research wished to sell CP/M on a royalty basis, while IBM sought a single license, and to change

891-515: A few developers and computer engineers still use it because it is close to the hardware. DOS's structure of accessing hardware directly allows it to be used in embedded devices . The final versions of DR-DOS are still aimed at this market. ROM-DOS is used as operating system for the Canon PowerShot Pro 70. On Linux , it is possible to run DOSEMU , a Linux-native virtual machine for running DOS programs at near native speed. There are

990-456: A few years. The DOS/V lacked its software library, so IBM Japan requested third-party companies to port their software to the DOS/V. The PS/55 Model 5535-S was released as a laptop terminal for the corporate sector. They only had to supply a few major business software to the DOS/V. In March 1991, IBM Japan released the PS/55note Model 5523-S which was the lower-price laptop computer. It was

1089-479: A file name with a space, has sometimes been used by viruses or hacking programs to obscure files from users who do not know how to access these locations. DOS was designed for the Intel 8088 processor, which can only directly access a maximum of 1 MiB of RAM. Both IBM and Microsoft chose 640 kibibytes (KiB) as the maximum amount of memory available to programs and reserved the remaining 384 KiB for video memory,

SECTION 10

#1732856044659

1188-511: A manifesto proposing the development of an open-source replacement. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. A kernel, the COMMAND.COM command line interpreter (shell), and core utilities were created by pooling code they had written or found available. There were several official pre-release distributions of FreeDOS before the FreeDOS 1.0 distribution

1287-658: A more user-friendly environment, numerous software manufacturers wrote file management programs that provided users with WIMP interfaces. Microsoft Windows is a notable example, eventually resulting in Microsoft Windows 9x becoming a self-contained program loader, and replacing DOS as the most-used PC-compatible program loader. Text user interface programs included Norton Commander , DOS Navigator , Volkov Commander , Quarterdesk DESQview , and Sidekick . Graphical user interface programs included Digital Research's GEM (originally written for CP/M) and GEOS . Eventually,

1386-641: A new computer to a distributed software application. An example might involve scaling out from one web server to three. High-performance computing applications, such as seismic analysis and biotechnology , scale workloads horizontally to support tasks that once would have required expensive supercomputers . Other workloads, such as large social networks, exceed the capacity of the largest supercomputer and can only be handled by scalable systems. Exploiting this scalability requires software for efficient resource management and maintenance. Scaling vertically (up/down) means adding resources to (or removing resources from)

1485-569: A new model of the PS/55 which was based on the PS/2 with Japanese language support. It is equipped with a proprietary video card, the Display Adapter, which has a high resolution text mode and a Japanese character set stored in a ROM on the card. It supports Japanese DOS K3.3, PC DOS 3.3 (English) and OS/2 . IBM DOS J4.0 was released in 1989. It combines Japanese DOS and PC DOS, which runs Japanese DOS as

1584-513: A number of other emulators for running DOS on various versions of Unix and Microsoft Windows such as DOSBox . DOSBox is designed for legacy gaming (e.g. King's Quest , Doom ) on modern operating systems. DOSBox includes its own implementation of DOS which is strongly tied to the emulator and cannot run on real hardware, but can also boot MS-DOS, FreeDOS, or other DOS operating systems if needed. MS-DOS and IBM PC DOS related operating systems are commonly associated with machines using

1683-413: A program run from one floppy while accessing its data on another. Hard drives were originally assigned the letters "C" and "D". DOS could only support one active partition per drive. As support for more hard drives became available, this developed into first assigning a drive letter to each drive's active primary partition , then making a second pass over the drives to allocate letters to logical drives in

1782-501: A retail version of MS-DOS, starting with MS-DOS 5.0. In the mid-1980s, Microsoft developed a multitasking version of DOS . This version of DOS is generally referred to as "European MS-DOS 4" because it was developed for ICL and licensed to several European companies. This version of DOS supports preemptive multitasking, shared memory, device helper services and New Executable ("NE") format executables. None of these features were used in later versions of DOS, but they were used to form

1881-566: A series of disagreements over two successor operating systems to DOS, OS/2 and Windows. They split development of their DOS systems as a result. The last retail version of MS-DOS was MS-DOS 6.22; after this, MS-DOS became part of Windows 95, 98 and Me. The last retail version of PC DOS was PC DOS 2000 (also called PC DOS 7 revision 1), though IBM did later develop PC DOS 7.10 for OEMs and internal use. The FreeDOS project began on 26 June 1994, when Microsoft announced it would no longer sell or support MS-DOS. Jim Hall then posted

1980-453: A single node, typically involving the addition of CPUs, memory or storage to a single computer. Benefits to scale-up include avoiding increases management complexity, more sophisticated programming to allocate tasks among resources and handle issues such as throughput, latency, synchronization across nodes. Moreover some applications do not scale horizontally . Network function virtualization defines these terms differently: scaling out/in

2079-408: A single warehouse for sorting, the system would not be as scalable, because one warehouse can handle only a limited number of packages. In computing, scalability is a characteristic of computers, networks, algorithms , networking protocols , programs and applications. An example is a search engine , which must support increasing numbers of users, and the number of topics it indexes . Webscale

SECTION 20

#1732856044659

2178-555: A strategically important product to popularize the DOS/V into the consumer market, and led to the success of subsequent consumer products such as the ThinkPad . However, the DOS/V itself sold much better than the 5523S because advanced users purchased it to build a Japanese language environment on their IBM compatible PCs. In 1992, IBM Japan released the PS/V (similar to the PS/ValuePoint ) and

2277-415: A time can use them, and DOS itself has no functionality to allow more than one program to execute at a time. The DOS kernel provides various functions for programs (an application program interface ), like character I/O, file management, memory management, program loading and termination. DOS provides the ability for shell scripting via batch files (with the filename extension .BAT ). Each line of

2376-561: A year Microsoft licensed MS-DOS to over 70 other companies, which supplied the operating system for their own hardware, sometimes under their own names. Microsoft later required the use of the MS-DOS name, with the exception of the IBM variant. IBM continued to develop their version, PC DOS , for the IBM PC. Digital Research became aware that an operating system similar to CP/M was being sold by IBM (under

2475-427: Is a computer architectural approach that brings the capabilities of large-scale cloud computing companies into enterprise data centers. In distributed systems , there are several definitions according to the authors, some considering the concepts of scalability a sub-part of elasticity , others as being distinct. According to Marc Brooker: "a system is scalable in the range where marginal cost of additional workload

2574-432: Is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft 's MS-DOS , both of which were introduced in 1981. Later compatible systems from other manufacturers include DR-DOS (1988), ROM-DOS (1989), PTS-DOS (1993), and FreeDOS (1998). MS-DOS dominated the IBM PC compatible market between 1981 and 1995. Although

2673-530: Is a real DOS, like MS-DOS 6.22 or PC DOS 5.00. One makes a bootable floppy disk of the DOS, adds a number of drivers from OS/2, and then creates a special image. The DOS booted this way has full access to the system, but provides its own drivers for hardware. One can use such a disk to access cdrom drives for which there is no OS/2 driver. In all 32-bit (IA-32) editions of the Windows NT family since 1993, DOS emulation

2772-667: Is a vital consideration for businesses aiming to meet customer expectations, remain competitive, and achieve sustainable growth. Factors influencing scalability include the flexibility of the production process, the adaptability of the workforce, and the integration of advanced technologies. By implementing scalable solutions, companies can optimize resource utilization, reduce costs, and streamline their operations. Scalability in industrial engineering and manufacturing enables businesses to respond to fluctuating market conditions, capitalize on emerging opportunities, and thrive in an ever-evolving global landscape. The Incident Command System (ICS)

2871-705: Is also 8.3 format but the maximum directory path length is 64 characters due to the internal current directory structure (CDS) tables that DOS maintains. Including the drive name, the maximum length of a fully qualified filename that DOS supports is 80 characters using the format drive:\path\filename.ext followed by a null byte. DOS uses the File Allocation Table (FAT) filesystem. This was originally FAT12 which supported up to 4078 clusters per drive. DOS 3.0 added support for FAT16 which used 16-bit allocation entries and supported up to 65518 clusters per drive. Compaq MS-DOS 3.31 added support for FAT16B which removed

2970-431: Is an optional built-in driver for a fourth line printer supported in some versions of DR-DOS since 7.02. CONFIG$ constitutes the real mode PnP manager in MS-DOS 7.0–8.0. AUX typically defaults to COM1 , and PRN to LPT1 ( LST ), but these defaults can be changed in some versions of DOS to point to other serial or parallel devices. The PLT device (present only in some HP OEM versions of MS-DOS)

3069-520: Is available in COMMAND.COM. Programs like the Microsoft CD-ROM Extensions (MSCDEX) provide access to files on CD-ROM disks. Some TSRs can even perform a rudimentary form of task switching. For example, the shareware program Back and Forth (1990) has a hotkey to save the state of the currently-running program to disk, load another program, and switch to it, making it possible to switch "back and forth" between programs (albeit slowly, due to

DOS/V - Misplaced Pages Continue

3168-408: Is based upon DOS 5. Although there is a default configuration (config.sys and autoexec.bat), one can use alternate files on a session-by-session basis. It is possible to load drivers in these files to access the host system, although these are typically third-party. Under OS/2 2.x and later, the DOS emulation is provided by DOSKRNL. This is a file that represents the combined IBMBIO.COM and IBMDOS.COM,

3267-502: Is invalid." These names (except for NUL) have continued to be supported in all versions of MS-DOS, PC DOS and DR-DOS ever since. LST was also available in some OEM versions of MS-DOS 1.25, whereas other OEM versions of MS-DOS 1.25 already used LPT1 (first line printer ) and COM1 (first serial communication device ) instead, as introduced with PC DOS. In addition to LPT1 and LPT2 as well as COM1 to COM3 , Hewlett-Packard's OEM version of MS-DOS 2.11 for

3366-413: Is likely to render the media unbootable. It is, however, possible to replace the shell at will, a method that can be used to start the execution of dedicated applications faster. This limitation does not apply to any version of DR DOS, where the system files can be located anywhere in the root directory and do not need to be contiguous. Therefore, system files can be simply copied to a disk provided that

3465-633: Is nearly constant." Serverless technologies fit this definition but you need to consider total cost of ownership not just the infra cost. In mathematics, scalability mostly refers to closure under scalar multiplication . In industrial engineering and manufacturing, scalability refers to the capacity of a process, system, or organization to handle a growing workload, adapt to increasing demands, and maintain operational efficiency. A scalable system can effectively manage increased production volumes, new product lines, or expanding markets without compromising quality or performance. In this context, scalability

3564-531: Is often advised to focus system design on hardware scalability rather than on capacity. It is typically cheaper to add a new node to a system in order to achieve improved performance than to partake in performance tuning to improve the capacity that each node can handle. But this approach can have diminishing returns (as discussed in performance engineering ). For example: suppose 70% of a program can be sped up if parallelized and run on multiple CPUs instead of one. If α {\displaystyle \alpha }

3663-504: Is provided by way of a virtual DOS machine (NTVDM). 64-bit (IA-64 and x86-64) versions of Windows do not support NTVDM and cannot run 16-bit DOS applications directly; third-party emulators such as DOSbox can be used to run DOS programs on those machines. DOS systems use a command-line interface . A program is started by entering its filename at the command prompt. DOS systems include utility programs and provide internal commands that do not correspond to programs. In an attempt to provide

3762-738: Is suitable when availability and responsiveness are rated higher than consistency, which is true for many web file-hosting services or web caches ( if you want the latest version, wait some seconds for it to propagate ). For all classical transaction-oriented applications, this design should be avoided. Many open-source and even commercial scale-out storage clusters, especially those built on top of standard PC hardware and networks, provide eventual consistency only, such as some NoSQL databases like CouchDB and others mentioned above. Write operations invalidate other copies, but often don't wait for their acknowledgements. Read operations typically don't check every redundant copy prior to answering, potentially missing

3861-693: Is the ability to scale by adding/removing resource instances (e.g., virtual machine), whereas scaling up/down is the ability to scale by changing allocated resources (e.g., memory/CPU/storage capacity). Scalability for databases requires that the database system be able to perform additional work given greater hardware resources, such as additional servers, processors, memory and storage. Workloads have continued to grow and demands on databases have followed suit. Algorithmic innovations include row-level locking and table and index partitioning. Architectural innovations include shared-nothing and shared-everything architectures for managing multi-server configurations. In

3960-413: Is the fraction of a calculation that is sequential, and 1 − α {\displaystyle 1-\alpha } is the fraction that can be parallelized, the maximum speedup that can be achieved by using P processors is given according to Amdahl's Law : Substituting the value for this example, using 4 processors gives Doubling the computing power to 8 processors gives Doubling

4059-469: Is the property of a system to handle a growing amount of work. One definition for software systems specifies that this may be done by adding resources to the system. In an economic context, a scalable business model implies that a company can increase sales given increased resources. For example, a package delivery system is scalable because more packages can be delivered by adding more delivery vehicles. However, if all packages had to first pass through

DOS/V - Misplaced Pages Continue

4158-714: Is used by emergency response agencies in the United States. ICS can scale resource coordination from a single-engine roadside brushfire to an interstate wildfire. The first resource on scene establishes command, with authority to order resources and delegate responsibility (managing five to seven officers, who will again delegate to up to seven, and on as the incident grows). As an incident expands, more senior officers assume command. Scalability can be measured over multiple dimensions, such as: Resources fall into two broad categories: horizontal and vertical. Scaling horizontally (out/in) means adding or removing nodes, such as adding

4257-597: The 80386 would realize his idea, but they were expensive hardwares as of 1987. In this era, Toshiba released the J-3100 laptop computer, and Microsoft introduced the AX architecture . IBM Japan didn't join in the AX consortium. His boss, Tsutomu Maruyama ( 丸山 力 ) , thought IBM's headquarters wouldn't allow to adopt the AX because they requested IBM Japan to use the same standard as worldwide IBM offices used. In October 1987, IBM Japan released

4356-492: The CRTC address wraparound. Most likely those were Super VGAs with more video memory than the original VGA (i.e. more than 256 KB). Software relying on the address wraparound was very rare and therefore the functionality was not necessarily correctly implemented in hardware. On the other hand, the split screen technique was relatively well documented and well understood, and commercial software (especially games) sometimes used it. It

4455-686: The HP Portable Plus also supported LST as alias for LPT2 and 82164A as alias for COM2 ; it also supported PLT for plotters . Otherwise, COM2 , LPT2 , LPT3 and the CLOCK$ (still named CLOCK in some issues of MS-DOS 2.11 ) clock device were introduced with DOS 2.0, and COM3 and COM4 were added with DOS 3.3. Only the multitasking MS-DOS 4 supported KEYBD$ and SCREEN$ . DR DOS 5.0 and higher and Multiuser DOS support an $ IDLE$ device for dynamic idle detection to saving power and improve multitasking. LPT4

4554-631: The Intel x86 or compatible CPUs , mainly IBM PC compatibles . Machine-dependent versions of MS-DOS were produced for many non-IBM-compatible x86 -based machines, with variations from relabelling of the Microsoft distribution under the manufacturer's name, to versions specifically designed to work with non-IBM-PC-compatible hardware. As long as application programs used DOS APIs instead of direct hardware access, they could run on both IBM-PC-compatible and incompatible machines. The original FreeDOS kernel, DOS-C ,

4653-503: The ThinkPad . They were based upon an architecture closer to PC compatibles, and intended to compete with rivals in the consumer market. As of December 1992, the PS/V was the most selling DOS/V computer. In January 1993, NEC released a new generation of the PC-98 to take back its initiative. NEC advertised that the scrolling speed of the word processor Ichitaro on the PC-9801BX was faster than on

4752-490: The extended partition , then a third pass to give any other non-active primary partitions their names (where such additional partitions existed and contained a DOS-supported file system). Lastly, DOS allocates letters for optical disc drives , RAM disks , and other hardware. Letter assignments usually occur in the order the drivers are loaded, but the drivers can instruct DOS to assign a different letter; drivers for network drives, for example, typically assign letters nearer to

4851-509: The read-only memory of adapters on some video and network peripherals, and the system's BIOS. By 1985, some DOS applications were already hitting the memory limit, while much of reserved was unused, depending on the machine's specifications. Specifications were developed to allow access to additional memory. The first was the Expanded Memory Specification (EMS) was designed to allow memory on an add-on card to be accessed via

4950-494: The 32‑ MiB drive limit and could support up to 512 MiB. Finally MS-DOS 7.1 (the DOS component of Windows 9x) added support for FAT32 which used 32-bit allocation entries and could support hard drives up to 137 GiB and beyond. Starting with DOS 3.1, file redirector support was added to DOS. This was initially used to support networking but was later used to support CD-ROM drives with MSCDEX . IBM PC DOS 4.0 also had preliminary installable file system (IFS) support but this

5049-407: The 5550 was expensive, it was mostly sold for large enterprises who used IBM's mainframe . The JX used 8088 processor instead of faster 8086 processor because IBM thought a consumer-class JX mustn't surpass a business-class 5550. It damaged buyer's reputations whatever the actual speed was. In another point, a software company said IBM was uncooperative for developing JX software. IBM Japan planned

SECTION 50

#1732856044659

5148-572: The 65,520-byte high memory area directly above the first megabyte of memory and the upper memory block area. Generally XMS support was provided by HIMEM.SYS or a V86 mode memory manager like QEMM or 386MAX which also supported EMS. Starting with DOS 5, DOS could directly take advantage of the HMA by loading its kernel code and disk buffers there via the DOS=HIGH statement in CONFIG.SYS. DOS 5+ also allowed

5247-591: The DOS virtual machine is provided by WINOLDAP. WinOldAp creates a virtual machine based on the program's PIF file, and the system state when Windows was loaded. The DOS graphics mode, both character and graphic, can be captured and run in the window. DOS applications can use the Windows clipboard by accessing extra published calls in WinOldAp, and one can paste text through the WinOldAp graphics. The emulated DOS in OS/2 and Windows NT

5346-556: The DOS/V run on other IBM compatible machines. The fact was that we developed it could run on Gateway 's and any machines, but we had to keep the secret, not to spread it, because there are lots of enemies inside the company. In short, it was a double-edged sword. If the DOS/V run on such cheap compatible machines, conversely the 5550 series which had taken high profit up may not be sold. In fact, 80% of staff in Yamato office opposed it. Maruyama and Mii had to convince IBM's branches to agree with

5445-644: The Japanese market, Compaq in 1992 and Dell in 1993. Fujitsu released IBM PC clones (FMV series) in October 1993, and about 200,000 units were shipped in 1994. The initial goal of DOS/V was to enable Japanese software to run on laptop computers based on the IBM global standards rather than the domestic computer architecture. As of 1989, the VGA was not common, but they expected the LCD panels with VGA resolution would be affordable within

5544-766: The Japanese mode (PS/55 mode) and PC DOS as the English mode (PS/2 mode). Although it had two separated modes that needed a reboot to switch between them, IBM Japan called it bilingual . This version requires the PS/55 display adapter. The first version of DOS/V, IBM DOS J4.0/V (J4.05/V), was released in the end of 1990. The word 'DOS/V' was quickly known to Japanese computer industry, but the DOS/V itself didn't spread quickly. As of 1991, some small companies sold American or Taiwanese computers in Japan, but DOS J4.0/V caused some issues on PC compatibles. Its EMS driver only supports IBM's Expanded Memory Adapter . The input method doesn't support

5643-545: The PS/55 Model 5535 which was a proprietary laptop using a special version of DOS. It was more expensive than the J-3100 because its LCD display used a non-standard 720×512 resolution. Hatori thought IBM needed to shift their own proprietary PC to IBM PC compatibles. Maruyama and Nobuo Mii thought Japan's closed PC market needed to be changed and this attempt couldn't be done by IBM alone. In summer of 1989, they decided to carry out

5742-458: The PS/V 2405-W. Yuzuru Takemura ( 竹村 譲 ) of IBM Japan said, "Let us suppose the movement towards Windows is inevitability. Processors and graphics cards will become faster and faster. If the PC-98 holds its architecture, it never beat our machine at speed. Windows is developed for the PC/AT architecture. Kanji glyphs are also supplied as a software font. The only thing IBM have to do is tuning up it for

5841-691: The US keyboard nor the Japanese AX keyboard, so it locates some keys at the wrong place. PS/55 keyboards were available from IBM, but it must be used with an AT to PS/2 adapter because AX machines (thus PC/AT clones) generally have the older 5-pin DIN connector . Scrolling text with the common Tseng Labs ET4000 graphics controller makes the screen unreadable. This issue can be fixed by the new /HS=LC switch of $ DISP.SYS in DOS J4.07/V. "Some VGA clones did not correctly implement

5940-536: The basis of the OS/2 1.0 kernel. This version of DOS is distinct from the widely released PC DOS 4.0 which was developed by IBM and based upon DOS 3.3. Digital Research attempted to regain the market lost from CP/M-86, initially with Concurrent DOS , FlexOS and DOS Plus (both compatible with both MS-DOS and CP/M-86 software), later with Multiuser DOS (compatible with both MS-DOS and CP/M-86 software) and DR DOS (compatible with MS-DOS software). Digital Research

6039-411: The boot sector is DR DOS compatible already. In PC DOS and DR DOS 5.0 and above, the DOS system files are named IBMBIO.COM instead of IO.SYS and IBMDOS.COM instead of MSDOS.SYS . Older versions of DR DOS used DRBIOS.SYS and DRBDOS.SYS instead. Starting with MS-DOS 7.0 the binary system files IO.SYS and MSDOS.SYS were combined into a single file IO.SYS whilst MSDOS.SYS became

SECTION 60

#1732856044659

6138-441: The context of scale-out data storage , scalability is defined as the maximum storage cluster size which guarantees full data consistency, meaning there is only ever one valid version of stored data in the whole cluster, independently from the number of redundant physical data copies. Clusters which provide "lazy" redundancy by updating copies in an asynchronous fashion are called 'eventually consistent' . This type of scale-out design

6237-404: The corresponding load drive whenever an application starts. There are reserved device names in DOS that cannot be used as filenames regardless of extension as they are occupied by built-in character devices. These restrictions also affect several Windows versions, in some cases causing crashes and security vulnerabilities. The reserved names are: In Windows 95 and Windows 98 , typing in

6336-499: The default OS kernel , though the MS-DOS component remained for compatibility. With Windows 95 and 98, but not ME, the MS-DOS component could be run without starting Windows. With DOS no longer required to use Windows, the majority of users stopped using it directly. As of 2024 , available compatible systems are FreeDOS , ROM-DOS , PTS-DOS , RxDOS and REAL/32 . Some computer manufacturers, including Dell and HP , sell computers with FreeDOS as an OEM operating system. And

6435-611: The development of DOS/V, disclose the architecture of PS/55, and found the PC Open Architecture Developers' Group (OADG). The DOS/V development team designed the DOS/V to be simple for better scalability and compatibility with original PC DOS. They had difficulty reducing text drawing time. "A stopwatch was a necessity for DOS/V development", Hatori said. IBM Japan announced the first version of DOS/V, IBM DOS J4.0/V, on 11 October 1990, and shipped out in November 1990. At

6534-1187: The disk access required). Back and Forth could not enable background processing however; that needed DESQview (on at least a 386 ). Scalability Social network analysis Small-world networks Centrality Motifs Graph theory Scaling Robustness Systems biology Dynamic networks Evolutionary computation Genetic algorithms Genetic programming Artificial life Machine learning Evolutionary developmental biology Artificial intelligence Evolutionary robotics Reaction–diffusion systems Partial differential equations Dissipative structures Percolation Cellular automata Spatial ecology Self-replication Conversation theory Entropy Feedback Goal-oriented Homeostasis Information theory Operationalization Second-order cybernetics Self-reference System dynamics Systems science Systems thinking Sensemaking Variety Ordinary differential equations Phase space Attractors Population dynamics Chaos Multistability Bifurcation Rational choice theory Bounded rationality Scalability

6633-530: The early 1980s, IBM Japan developed two x86 -based personal computer lines for the Asia-Pacific region, IBM 5550 and IBM JX . The 5550 reads Kanji fonts from the disk, and draws text as graphic characters on 1024×768 high resolution monitor. The JX extends IBM PCjr and IBM PC architecture. It supports English and Japanese versions of PC DOS with 720×512 resolution monitor. Both machines couldn't break dominant NEC's PC-98 in consumer market in Japan. Because

6732-459: The end of the alphabet. Because DOS applications use these drive letters directly (unlike the /dev directory in Unix-like systems), they can be disrupted by adding new hardware that needs a drive letter. An example is the addition of a new hard drive having a primary partition where a pre-existing hard drive contains logical drives in extended partitions; the new drive will be assigned a letter that

6831-515: The font driver, the display driver and the input assisted subsystem driver. The font driver loads a complete set of the glyphs from a font file into the extended memory . The display driver sets the 640×480 graphics mode on the VGA, and allocates about 20 KB of the conventional memory for text, called the simulated video buffer . A DOS/V program writes the codes of the characters to the simulated video buffer through DOS output functions, or writes them directly and calls driver's function to refresh

6930-413: The hard disk rather than on special chips as in the preceding AX architecture . As with AX, its great value for the Japanese computing industry is in allowing compatibility with foreign software. This had not been possible under NEC 's proprietary PC-98 system, which was the market leader before DOS/V emerged. DOS/V stands for "Disk Operating System/ VGA " (not "version 5"; DOS/V came out at approximately

7029-400: The hardware directly, usually resulting in each application having its own set of device drivers for each hardware peripheral. Hardware manufacturers would release specifications to ensure device drivers for popular applications were available. The DOS system files loaded by the boot sector must be contiguous and be the first two directory entries . As such, removing and adding this file

7128-575: The introduction of Xenix . The company planned to improve MS-DOS over time, so it would be almost indistinguishable from single-user Xenix, or XEDOS , which would also run on the Motorola 68000 , Zilog Z-8000 , and LSI-11 ; they would be upwardly compatible with Xenix, which BYTE in 1983 described as "the multi-user MS-DOS of the future". IBM, however, did not want to replace DOS. After AT&T began selling Unix, Microsoft and IBM began developing OS/2 as an alternative. The two companies later had

7227-458: The location of the reserved name (such as CON/CON, AUX/AUX, or PRN/PRN) crashes the operating system, of which Microsoft has provided a security fix for the issue. In Windows XP , the name of the file or folder using a reserved name silently reverts to its previous name, with no notification or error message. In Windows Vista and later, attempting to use a reserved name for a file or folder brings up an error message saying "The specified device name

7326-399: The manufacturers of major DOS systems began to include their own environment managers. MS-DOS/IBM DOS 4 included DOS Shell ; DR DOS 5.0, released the following year, included ViewMAX , based upon GEM. Although DOS is not a multitasking operating system, it does provide a terminate-and-stay-resident (TSR) function which allows programs to remain resident in memory. These programs can hook

7425-431: The name has come to be identified specifically with this particular family of operating systems, DOS is a platform-independent acronym for disk operating system , whose use predates the IBM PC. Dozens of other operating systems also use the acronym, beginning with the mainframe DOS/360 from 1966. Others include Apple DOS , Apple ProDOS , Atari DOS , Commodore DOS , TRSDOS , and AmigaDOS . IBM PC DOS (and

7524-668: The name to "PC DOS". Digital Research founder Gary Kildall refused, and IBM withdrew. IBM again approached Bill Gates. Gates in turn approached Seattle Computer Products . There, programmer Tim Paterson had developed a variant of CP/M-80 , intended as an internal product for testing SCP's new 16-bit Intel 8086 CPU card for the S-100 bus . The system was initially named QDOS (Quick and Dirty Operating System), before being made commercially available as 86-DOS . Microsoft purchased 86-DOS, allegedly for US$ 50,000. This became Microsoft Disk Operating System, MS-DOS, introduced in 1981. Within

7623-673: The plan. In the beginning of December 1990, Maruyama went to IBM's Management Committee, and presented his plan "The low-end PC strategy in Japan". At the committee, a topic usually took 15 minutes, but his topic took an hour. The plan was finally approved by John Akers . After the committee, Susumu Furukawa, a president of Microsoft Japan , could make an appointment with IBM Japan to share the source code of DOS/V. On 20 December 1990, IBM Japan announced they founded OADG and Microsoft would supply DOS/V for other PC manufacturers. From 1992 to 1994, many Japanese manufacturers began selling IBM PC clones with DOS/V. Some global PC manufacturers entered into

7722-415: The preceding write operation. The large amount of metadata signal traffic would require specialized hardware and short distances to be handled with acceptable performance (i.e., act like a non-clustered storage device or database). Whenever strong data consistency is expected, look for these indicators: Indicators for eventually consistent designs (not suitable for transactional applications!) are: It

7821-615: The processing power has only sped up the process by roughly one-fifth. If the whole problem was parallelizable, the speed would also double. Therefore, throwing in more hardware is not necessarily the optimal approach. In distributed systems , you can use Universal Scalability Law (USL) to model and to optimize scalability of your system. USL is coined by Neil J. Gunther and quantifies scalability based on parameters such as contention and coherency. Contention refers to delay due to waiting or queueing for shared resources. Coherence refers to delay for data to become consistent. For example, having

7920-501: The same name that IBM insisted upon for CP/M), and threatened legal action. IBM responded by offering an agreement: they would give PC consumers a choice of PC DOS or CP/M-86 , Kildall's 8086 version. Side-by-side, CP/M cost US$ 200 more than PC DOS, and sales were low. CP/M faded, with MS-DOS and PC DOS becoming the marketed operating system for PCs and PC compatibles. Microsoft originally sold MS-DOS only to original equipment manufacturers (OEMs). One major reason for this

8019-448: The same time as DOS 5). In Japan, IBM compatible PCs became popular along with DOS/V, so they were often referred to as "DOS/V machine" or "DOS/V pasocom " even though DOS/V operating systems are no longer common by the late 1990s. The promotion of DOS/V was done by IBM and its consortium called PC Open Architecture Developers' Group (OADG). Digital Research released a Japanese DOS/V-compatible version of DR DOS 6.0 in 1992. In

8118-487: The same time, IBM Japan released the PS/55 Model 5535-S, a laptop computer with VGA resolution. The announcement letter stated DOS/V was designed for low-end desktops and laptops of PS/55, but users reported on BBS that they could run DOS/V on IBM PC clones . The development team unofficially confirmed these comments, and modified incompatibilities of DOS/V. It was a secret inside the company because it would prevent sales of PS/55 and meet with opposition. Hatori said, We hid

8217-490: The same time, they were separately developed. MS-DOS 6.2/V Upgrade is the only Japanese version of MS-DOS released by Microsoft under its own brand for retail sales. Microsoft Japan continued selling it after Microsoft released MS-DOS 6.22 to resolve patent infringement of DoubleSpace disk compression . IBM Japan ended support for PC DOS 2000 on 31 January 2001, and Microsoft Japan ended support for MS-DOS on 31 December 2001. Japanese versions of Windows 2000 and XP have

8316-453: The screen. The display driver copies the font bitmap data from the extended memory to the actual video memory , corresponding to the simulated video buffer. The input assisted subsystem driver communicates with optional input methods and enables the text editing in the on-the-spot or below-the-spot styles. Without installing these drivers, the DOS/V is equivalent to the generic MS-DOS without DBCS code page support. In 1988, IBM Japan released

8415-501: The separately sold MS-DOS ) and its predecessor, 86-DOS , ran on Intel 8086 16-bit processors. It was developed to be similar to Digital Research 's CP/M —the dominant disk operating system for 8-bit Intel 8080 and Zilog Z80 microcomputers—in order to simplify porting CP/M applications to MS-DOS. When IBM introduced the IBM PC , built with the Intel 8088 microprocessor, they needed an operating system. Chairman John Opel had

8514-506: The system calls are passed through to the OS/2 windowing services. DOS programs run in their own environment, the bulk of the DOS utilities are provided by bound DOS / OS2 applications in the \OS2 directory. OS/2 can run Windows 3.1 applications by using a modified copy of Windows (Win-OS/2). The modifications allow Windows 3.1 programs to run seamlessly on the OS/2 desktop, or one can start a WinOS/2 desktop, similar to starting Windows from DOS. OS/2 allows for 'DOS from Drive A:', (VMDISK). This

8613-606: The system timer or keyboard interrupts to allow themselves to run tasks in the background or to be invoked at any time, preempting the current running program and effectively implementing a simple form of multitasking on a program-specific basis. The DOS PRINT command does this to implement background print spooling. Borland Sidekick , a popup personal information manager (PIM), also uses this technique. Terminate-and-stay-resident programs are also used to provide additional features not available by default. Programs like CED and DOSKEY provide command-line editing facilities beyond what

8712-685: The use of available upper memory blocks via the DOS=UMB statement in CONFIG.SYS. The DOS emulation in OS/2 and Windows runs in much the same way as native applications do. They can access all of the drives and services, and can even use the host's clipboard services. Because the drivers for file systems and such forth reside in the host system, the DOS emulation needs only provide a DOS API translation layer which converts DOS calls to OS/2 or Windows system calls. The translation layer generally also converts BIOS calls and virtualizes common I/O port accesses which many DOS programs commonly use. In Windows 3.1 and 9x,

8811-417: The user changes them. Under DOS, this problem can be worked around by defining a SUBST drive and installing the DOS program into this logical drive. The assignment of this drive would then be changed in a batch job whenever the application starts. Under some versions of Concurrent DOS , as well as under Multiuser DOS , System Manager and REAL/32 , the reserved drive letter L: will automatically be assigned to

8910-448: The video card. On the different architecture, it will be hard to tune up Windows". In 1993, Microsoft Japan released first retail versions of Windows ( Windows 3.1 ) for both DOS/V and PC-98. The DOS/V contributed the dawn of IBM PC clones in Japan, yet PC-98 had kept 50% of market share until 1996. It was turned round by the release of Windows 95 . Three device drivers enable DBCS code page support in DOS on IBM PC compatibles with VGA;

9009-416: Was bought by Novell , and DR DOS became PalmDOS and Novell DOS ; later, it was part of Caldera (under the names OpenDOS and DR-DOS 7.02 / 7.03 ), Lineo , and DeviceLogics . Gordon Letwin wrote in 1995 that "DOS was, when we first wrote it, a one-time throw-away product intended to keep IBM happy so that they'd buy our languages." Microsoft expected that it would be an interim solution before

9108-604: Was delayed because IBM and Microsoft disputed how to implement the API for input methods. It took a few months to make an agreement that the OEM adaptation kit (OAK) of MS-DOS 5.0/V provided both IAS (Input Assist Subsystem) and MKKC (Microsoft Kana -Kanji Conversion). Microsoft planned to add the AX application support into DOS/V, but cancelled it because its beta release was strongly criticized by users for lacking compatibility. Some PC manufacturers couldn't wait Microsoft's DOS/V. Toshiba developed

9207-508: Was derived from DOS/NT for the Motorola 68000 series of CPUs in the early 1990s. While these systems loosely resembled the DOS architecture, applications were not binary compatible due to the incompatible instruction sets of these non-x86-CPUs. However, applications written in high-level languages could be ported easily. DOS is a single-user, single-tasking operating system with basic kernel functions that are non-reentrant : only one program at

9306-461: Was previously assigned to one of the extended partition logical drives. Moreover, even adding a new hard drive having only logical drives in an extended partition would still disrupt the letters of RAM disks and optical drives. This problem persisted through Microsoft's DOS-based 9x versions of Windows until they were replaced by versions based on the NT line, which preserves the letters of existing drives until

9405-467: Was reconfigurable as well. Filenames ended with a colon ( : ) such as NUL: conventionally indicate device names, but the colon is not actually a part of the name of the built-in device drivers. Colons are not necessary to be typed in some cases, for example: It is still possible to create files or directories using these reserved device names, such as through direct editing of directory data structures in disk sectors. Such naming, such as starting

9504-532: Was released on 3 September 2006. Made available under the GNU General Public License (GPL), FreeDOS does not require license fees or royalties. Early versions of Microsoft Windows ran on MS-DOS. By the early 1990s, the Windows graphical shell saw heavy use on new DOS systems. In 1995, Windows 95 was bundled as a standalone operating system that did not require a separate DOS license. Windows 95 (and Windows 98 and ME, that followed it) took over as

9603-415: Was that not all early PCs were 100% IBM PC compatible . DOS was structured such that there was a separation between the system specific device driver code ( IO.SYS ) and the DOS kernel ( MSDOS.SYS ). Microsoft provided an OEM Adaptation Kit (OAK) which allowed OEMs to customize the device driver code to their particular system. By the early 1990s, most PCs adhered to IBM PC standards so Microsoft began selling

9702-618: Was therefore likely to be tested and properly implemented in hardware." IBM Japan released DOS J5.0/V in October 1991, and DOS J5.0 in December 1991. DOS J5.0 combines Japanese DOS and DOS/V. This is the last version developed for the PS/55 display adapter. DOS J5.02/V was released in March 1992. It added official support for the IBM PS/2 and the US English layout keyboard. The development of MS-DOS 5.0/V

9801-518: Was unused and removed in DOS 5.0. DOS also supported Block Devices ("Disk Drive" devices) loaded from CONFIG.SYS that could be used under the DOS file system to support network devices. In DOS, drives are referred to by identifying letters. Standard practice is to reserve "A" and "B" for floppy drives . On systems with only one floppy drive DOS assigns both letters to the drive, prompting the user to swap disks as programs alternate access between them. This facilitates copying from floppy to floppy or having

#658341