|
Rational Systems
Tenberry Software (previously Rational Systems) was a software company notable for the development of DOS/16M and DOS/4G, which were the first industry standard DOS extender A DOS extender is a computer software program running under DOS that enables software to run in a protected mode environment even though the host operating system is only capable of operating in real mode. DOS extenders were initially developed ...s. See also * Phar Lap - competitor References External links Tenberry Software Software companies of the United States Companies based in Phoenix, Arizona {{US-software-company-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS/4G
DOS/4G is a 32-bit DOS extender developed by Rational Systems (later Tenberry Software). It allows DOS programs to eliminate the 640 KB conventional memory limit by addressing up to 64 MB of extended memory on Intel 80386 and above machines. Features Functioning as a highly flexible and reusable memory extension library, DOS/4G allowed programmers to access extended memory without writing specialized code. It embeds itself in the executable file at linking time and executes before main application code, so usually DOS/4G initialization messages show up at launch. It can in principle operate within MS-DOS, PC DOS, DR-DOS and other DOS clones, the DOS boxes of OS/2, Microsoft Windows, Windows NT and Windows 95, and DOS emulators such as DOSBox. However, in practice few DOS/4G games or other applications will run on non-DOS-based versions of Windows, including Windows NT, Windows 2000 and Windows XP, since none of these allow direct access to the hardware as was used for disp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOS Extender
A DOS extender is a computer software program running under DOS that enables software to run in a protected mode environment even though the host operating system is only capable of operating in real mode. DOS extenders were initially developed in the 1980s following the introduction of the Intel 80286 processor (and later expanded upon with the Intel 80386), to cope with the memory limitations of DOS. DOS extender operation A DOS extender is a program that "extends" DOS so that programs running in protected mode can transparently interface with the underlying DOS API. This was necessary because many of the functions provided by DOS require 16-bit segment and offset addresses pointing to memory locations within the Conventional memory, first 640 kilobytes of memory. Protected mode, however, uses an incompatible addressing method where the segment registers (now called selectors) are used to point to an entry in the Global Descriptor Table which describes the characteristics of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phar Lap (company)
Phar Lap Software, Inc., was a software company specializing in software development tools for DOS operating systems. The company was named after the champion New Zealand racehorse Phar Lap. They were most noted for their software allowing developers to access memory beyond the 640 KiB limit of DOS (DOS extenders) and were an author of the VCPI standard. Phar Lap Software, Inc. was founded in April 1986 by Richard M. Smith, Robert Moote, and John M. Benfatto. Their first major success, ''386, DOS-Extender'', a 32-bit protected mode development tool, was released in November 1986. Phar Lap’s product line was expanded to include ''386, VMM'', a virtual memory add-in driver, ''LinkLoc'', a linker-locator for embedded development; cross tools for embedded development; and ''286, DOS-Extender'', a DOS extender that emulated an OS/2 environment, complete with the OS/2 API and protected mode, in contrast with Microsoft's OS/2 API emulation, which ran OS/2 applications in real mode a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Companies Of The United States
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists of machine language instructions supported by an individual processor—typically a central processing unit (CPU) or a graphics processing unit (GPU). Machine language consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction may also invoke one of many input or output operations, for example displaying some text on a computer screen; causing state changes which should be visible to the user. The processor executes the instructions in the order they are provided, unless it is instructed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> Software Companies Of The United States")