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| Industry | Software |
|---|---|
| Founded | April 1986 |
| Headquarters | Cambridge, Massachusetts |
Key people | Richard M. Smith, Robert Moote, and John M. Benfatto |
| Products | Development tools forDOS,DOS extenders |
| Website | pharlap.com (archived) |
Phar Lap Software, Inc., was a software company specializing in software development tools forDOSoperating systems. The company was named after the champion New ZealandracehorsePhar Lap. They were most noted for their software allowing developers to access memory beyond the 640KiB limit of DOS (DOS extenders) and were an author of theVCPI 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, a32-bitprotected mode development tool, was released in November 1986.
Phar Lap’s product line was expanded to include386|VMM, avirtual memory add-indriver,LinkLoc, alinker-locator for embedded development; cross tools for embedded development; and286|DOS-Extender, a DOS extender thatemulated anOS/2 environment, complete with the OS/2API and protected mode, in contrast with Microsoft's OS/2 API emulation, which ran OS/2 applications inreal mode and only supported a subset of the OS/2 API, called theFamily API. Therefore, it was often bound with existing OS/2 applications, replacing Microsoft's OS/2 API emulation for those applications that needed access to extended memory in DOS. Later on theTNTDOS extender was created, which was a version of386|DOS-Extender that emulated theWin32 environment, complete with flat address space and threading. Again this DOS extender was often bound to existing Win32 applications.MASM 6.1 and the 16-bit version of theVisual C++ 1.0 compiler were Win32 applications written for abeta version ofWindows NT that was bound with theTNT DOS Extender. The Win32 executables referenced functions such as RtlExAllocateHeap in ntdll.dll, which did not exist in the final ntdll.dll, so if Windows even allowed you to run it (with a MajorSubsystemVersion of 3 it doesn't allow it in modern Windows), you would get an error about that function not being found. But a utility called Beta2Fix.exe could be run, which replaced the referenced to ntdll.dll to beta2.dll, then if you put the (provided) beta2.dll in your path, it would implement those old functions as calls to the new somewhat-equivalent new functions such as RtlAllocateHeap. This was fixed in MASM 6.11 and Visual C++ 1.5.
Phar Lap developed theVirtual Control Program Interface (VCPI) specification in cooperation withQuarterdeck Office Systems, who produced theDESQview task-switching software. Phar Lap was also a member of the 12-firm committee that designed theDOS Protected Mode Interface (DPMI). VCPI and DPMI are industry standards allowing DOS extenders to co-exist withexpanded memory (EMS) emulators and multi-tasking environments.
Phar Lap received several major PC industry awards for VCPI,386|DOS-Extender, and286|DOS-Extender.
32-bit Windows applications could directly address all the memory thepersonal computer would support, so memory extenders were no longer needed.
Phar Lap is now part ofIntervalZero, formerlyArdence, which produces, among other products, thePhar Lap ETSreal-time operating system,[1] used for instance onLabVIEW real-time targets.
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