Phar Lap (company)

Phar Lap (company)

Phar Lap was a software company specializing in software development tools for the MS-DOS/PC-DOS operating systems. 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 and only supported a subset of the OS/2 API, called the Family 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 the TNT DOS extender was created, which was a version of 386|DOS-Extender that emulated the Win32 environment, complete with flat address space and threading. Again this DOS extender were often bound to existing Win32 applications. Unfortunately, MASM 6.1 and the 16-bit version of the Visual C++ 1.0 compiler were Win32 applications written for a beta version of Windows NT that was bound with the TNT DOS Extender, which means it could not run on the final version of Windows NT until Beta2Fix.exe was run, which replaced all references to NTDLL.DLL to BETA2.DLL. This was fixed in MASM 6.11 and Visual C++ 1.5. Much later the HX DOS Extender product was created that also emulates the Win32 environment on DOS, has been under heavy development from 2004 up to now (2007), and achieved a much better compatibility than any other attempt before.

Phar Lap developed the Virtual Control Program Interface (VCPI) specification in cooperation with Quarterdeck Office Systems, who produced the DesqView task-switching software. Phar Lap was also a member of the 12-firm committee that designed the DOS Protected Mode Interface (DPMI). VCPI and DPMI are industry standards allowing DOS extenders to co-exist with expanded memory (EMS) emulators and multi-tasking environments.

Phar Lap received several major PC industry awards for VCPI, 386|DOS-Extender, and 286|DOS-Extender.

Phar Lap was named for the great New Zealand race horse Phar Lap. The horse was rather inelegant in appearance, but performed spectacularly, setting everyone on their heels until he died a mysterious death. Software allowing application programs to reach beyond the 640KB limit was a brilliant hack: it was not elegant in appearance, but it performed spectacularly, setting everyone on their heels when it worked correctly, and causing programs to die mysterious deaths when utilized by a careless programmer.

There was no mystery when the market for DOS extenders died, however; they were not needed by 32-bit Windows applications which could directly address all the memory the computer hardware would support.

Phar Lap is now part of Ardence which produces, among other products, the Phar Lap ETS real-time operating system, used for instance on LabVIEW real-time targets.


External links

Search another word or see Phar Lap (company)on Dictionary | Thesaurus |Spanish
Copyright © 2015, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature