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DOS Protected Mode Services
DOS Protected Mode Services (DPMS) is a set of extended DOS memory management services to allow DPMS-enabled DOS drivers to load and execute in extended memory and protected mode. Not being a DOS extender by itself, DPMS is a minimal set of extended DOS memory management services to allow slightly modified DOS resident system extensions ( RSX) such as device drivers or terminate-and-stay-resident programs (TSRs) (as so called ''DPMS clients'') to relocate themselves into extended memory and run in 16-bit or 32-bit protected mode while leaving only a tiny stub in conventional memory as an interface to communicate with the conventional DOS environment. The DPMS clients do so through DPMS services provided by a previously loaded ''DPMS server''. The necessary size of the remaining stub depends on the type of driver, but often can be reduced to a few hundred bytes for just the header even for complex drivers. By executing the driver in extended memory and freeing up conventio ... [...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 (API) called the ''Extended Memory Specification'' (XMS). This API is implemented by a driver (such as HIMEM.SYS) or the operating system kernel, 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 incompat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows 9x
Windows 9x is a generic term referring to a line of discontinued Microsoft Windows operating systems released from 1995 to 2000 and supported until 2006, which were based on the kernel introduced in Windows 95 and modified in succeeding versions, with its underlying foundation based on MS-DOS. The first version in the 9x series was Windows 95, which was succeeded by Windows 98 and then Windows Me, which was the third and last version of Windows on the 9x line, until the series was superseded by Windows XP. Windows 9x is predominantly known for its use in home desktops. In 1998, Windows made up 82% of operating system market share. The internal release number for versions of Windows 9x is 4.x. The internal versions for Windows 95, 98, and Me are 4.0, 4.1, and 4.9, respectively. Previous MS-DOS-based versions of Windows used version numbers of 3.2 or lower. Windows NT, which was aimed at professional users such as networks and businesses, used a similar but separate version num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DR DOS "Panther"
DR-DOS is a disk operating system for IBM PC compatibles, originally developed by Gary A. Kildall's Digital Research, Digital Research, Inc. and derived from Concurrent PCÂ DOS 6.0, which was an advanced successor of CP/M-86. Upon its introduction in 1988, it was the first DOS that attempted to be Binary compatibility, compatible with IBM PC DOS and MS-DOS. Its first release was version 3.31, named so that it would match MS-DOS's then-current version. DR DOS 5.0 was released in 1990 as the first to be sold in retail; it was critically acclaimed and led to DR DOS becoming the main rival to Microsoft's MS-DOS, who quickly responded with its own MS-DOS 5.0 but releasing over a year later. It introduced a graphical user interface layer called ViewMAX. DR DOS 6.0 was released in 1991; then with Novell's acquisition of Digital Research, the following version was named Novell DOS 7.0 in 1994. After another sale, to Caldera (company), Caldera, updated versions were released partly op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
