MS-DOS was a renamed anatomy of 86-DOS – artlessly accepted as the Quick-and-Dirty Operating Arrangement or Q-DOS3 – endemic by Seattle Computer Products, accounting by Tim Paterson.3 Microsoft bare an operating arrangement for the then-new Intel 8086 but it had none available, so it bought 86-DOS for $75,000 and accountant it as its own again appear a adaptation of it as MS-DOS 1.0.3 Development started in 1981, and MS-DOS 1.0 was appear with the IBM PC in 1982.3 (86-DOS, in turn, was a carbon of Digital Research's CP/M (for 8080/Z80 processors), ported to run on 8086 processors and with two notable differences compared to CP/M, an bigger deejay area buffering argumentation and the addition of FAT12 instead of the CP/M filesystem. This became accessible because of the added availability of RAM compared to what was about accessible back CP/M was advised originally.)
Originally MS-DOS was advised to be an operating arrangement that could run on any 8086-family computer. Each computer would accept its own audible accouterments and its own adaptation of MS-DOS, agnate to the bearings that existed for CP/M, and with MS-DOS battling the aforementioned band-aid as CP/M to acclimate for altered accouterments platforms. To this end, MS-DOS was advised with a modular anatomy with centralized accessory drivers, minimally for primary deejay drives and the console, chip with the atom and loaded by the cossack loader, and installable accessory drivers for added accessories loaded and chip at cossack time. The OEM would use a development kit provided by Microsoft to body a adaptation of MS-DOS with their basal I/O drivers and a accepted Microsoft kernel, which they would about accumulation on deejay to end users forth with the hardware. Thus, there were abounding altered versions of "MS-DOS" for altered hardware, and there is a aloft acumen amid an IBM-compatible (or ISA) apparatus and an MS-DOS compatible machine. Some machines, like the Tandy 2000, were MS-DOS accordant but not IBM-compatible, so they could alone runcomputer appliance accounting alone for MS-DOS after assurance on the borderline accouterments of the IBM PC architecture.
This architectonics would accept formed able-bodied for compatibility, if appliance programs had alone acclimated MS-DOS casework to accomplish accessory I/O, and absolutely the aforementioned architectonics aesthetics is embodied in Windows NT (see Accouterments Abstraction Layer). However, in MS-DOS's aboriginal days, the greater acceleration accessible by programs through absolute ascendancy of accouterments was of accurate importance, abnormally for games, which generally pushed the banned of their abreast hardware. Actual anon an IBM-compatible architectonics became the goal, and afore continued all 8086-family computers carefully emulated IBM's hardware, and alone a distinct adaptation of MS-DOS for a anchored accouterments belvedere was bare for the market. This adaptation is the adaptation of MS-DOS that is discussed here, as the dozens of added OEM versions of "MS-DOS" were alone accordant to the systems they were advised for, and in any case were actual agnate in action and adequacy to the same-numbered accepted adaptation for the IBM PC, with a few notable exceptions.
While MS-DOS appeared on PC clones, accurate IBM computers acclimated PC DOS, a rebranded anatomy of MS-DOS. Ironically, the assurance on IBM-compatible accouterments acquired aloft problems for the computer industry back the aboriginal architectonics had to be changed. For example, the aboriginal architectonics could abutment no added than 640 kilobytes of anamnesis (the 640 KB barrier), because IBM's accouterments architectonics aloof the abode amplitude aloft this absolute for borderline accessories and ROM. Manufacturers had to advance complicated schemes (EMS and XMS, and added accessory proprietary ones) to admission added memory. This limitation would not accept been a botheration if the aboriginal abstraction of interfacing with accouterments through MS-DOS had endured. (However, MS-DOS was additionally a real-mode operating system, and the Intel x86 architectonics alone supports up to 1 MB of anamnesis abode amplitude in Real Mode, alike on Pentium 4 and after x86 CPUs, so for simple admission to megabytes of memory, MS-DOS would accept had to be rewritten to run in 80286 or 80386 Protected Mode.) Also, Microsoft originally declared MS-DOS as "an operating arrangement for Intel 8086-based microcomputers", and the 8086 CPU (and its accessory the 8088) itself has alone 1 MiB of absolute anamnesis abode space.
Originally MS-DOS was advised to be an operating arrangement that could run on any 8086-family computer. Each computer would accept its own audible accouterments and its own adaptation of MS-DOS, agnate to the bearings that existed for CP/M, and with MS-DOS battling the aforementioned band-aid as CP/M to acclimate for altered accouterments platforms. To this end, MS-DOS was advised with a modular anatomy with centralized accessory drivers, minimally for primary deejay drives and the console, chip with the atom and loaded by the cossack loader, and installable accessory drivers for added accessories loaded and chip at cossack time. The OEM would use a development kit provided by Microsoft to body a adaptation of MS-DOS with their basal I/O drivers and a accepted Microsoft kernel, which they would about accumulation on deejay to end users forth with the hardware. Thus, there were abounding altered versions of "MS-DOS" for altered hardware, and there is a aloft acumen amid an IBM-compatible (or ISA) apparatus and an MS-DOS compatible machine. Some machines, like the Tandy 2000, were MS-DOS accordant but not IBM-compatible, so they could alone runcomputer appliance accounting alone for MS-DOS after assurance on the borderline accouterments of the IBM PC architecture.
This architectonics would accept formed able-bodied for compatibility, if appliance programs had alone acclimated MS-DOS casework to accomplish accessory I/O, and absolutely the aforementioned architectonics aesthetics is embodied in Windows NT (see Accouterments Abstraction Layer). However, in MS-DOS's aboriginal days, the greater acceleration accessible by programs through absolute ascendancy of accouterments was of accurate importance, abnormally for games, which generally pushed the banned of their abreast hardware. Actual anon an IBM-compatible architectonics became the goal, and afore continued all 8086-family computers carefully emulated IBM's hardware, and alone a distinct adaptation of MS-DOS for a anchored accouterments belvedere was bare for the market. This adaptation is the adaptation of MS-DOS that is discussed here, as the dozens of added OEM versions of "MS-DOS" were alone accordant to the systems they were advised for, and in any case were actual agnate in action and adequacy to the same-numbered accepted adaptation for the IBM PC, with a few notable exceptions.
While MS-DOS appeared on PC clones, accurate IBM computers acclimated PC DOS, a rebranded anatomy of MS-DOS. Ironically, the assurance on IBM-compatible accouterments acquired aloft problems for the computer industry back the aboriginal architectonics had to be changed. For example, the aboriginal architectonics could abutment no added than 640 kilobytes of anamnesis (the 640 KB barrier), because IBM's accouterments architectonics aloof the abode amplitude aloft this absolute for borderline accessories and ROM. Manufacturers had to advance complicated schemes (EMS and XMS, and added accessory proprietary ones) to admission added memory. This limitation would not accept been a botheration if the aboriginal abstraction of interfacing with accouterments through MS-DOS had endured. (However, MS-DOS was additionally a real-mode operating system, and the Intel x86 architectonics alone supports up to 1 MB of anamnesis abode amplitude in Real Mode, alike on Pentium 4 and after x86 CPUs, so for simple admission to megabytes of memory, MS-DOS would accept had to be rewritten to run in 80286 or 80386 Protected Mode.) Also, Microsoft originally declared MS-DOS as "an operating arrangement for Intel 8086-based microcomputers", and the 8086 CPU (and its accessory the 8088) itself has alone 1 MiB of absolute anamnesis abode space.
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