PA-RISC information - since 1999

Other on PA-RISC

Overview

There were a few, more specialized PA-RISC operating systems developed by vendors for their own, special PA-RISC computers. This includes SPP-UX, a Mach-based Unix, developed by Convex for its Exemplar mainframes and Stratus VOS and FTX, ported to the fault-tolerant Continuum PA-RISC servers.

SPP-UX

Convex SPP1000
© Convex 1994

The Exemplar Operating System, SPP-UX, was a scalable Unix based on Mach developed by Convex for its SPP1000 and SPP2000 mainframe computers with up to 128 or 512 processors. SPP-UX implemented a distributed architecture that was supposed to look like (emulate) HP-UX for developers but was very different below the userland. It probably was released between 1993 and 1999?

The SPP-UX kernel and architecture was based on a Mach 3.0 distributed microkernel and was taken over by HP during the acquisition of Convex and its Exemplar SPP computers. Each hypernode of the SPP computers ran an independent instance of the Mach microkernel.

There were three (four) main layers for SPP-UX:

  1. Distributed kernel: Based on an enhanced Mach 3.0 microkernel, supposedly OSF 1/AD Mach from OSF RI, that was targeted for coupled SMP systems to support highly parallel applications; message-passing paradigm for NUMA computers
  2. HP-UX compatibility: Second operating system layer compatible to HP-UX, to enable running HP-UX applications on SPP-UX, supposedly emulated HP-UX APIs and ABIs; management of distributed resources, processors, simultaneous users, process scheduler; supported parallel jobs as well as multiprocessing of single-thread
  3. Extensions and features: Central management, open systems and standards like POSIX, specialized programming and development environment
  4. Lastly, the applications: Possible were HP Series 700 (stock HP-UX), C Series and MPP applications

SPP/UX supported the following hardware:

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Stratus FTX and VOS

Stratus Technologies ported its custom operating systems to its fault tolerant Continuum PA-RISC servers in the 1990s: both Unix and transaction-oriented systems. Operating system support was split between Stratus Continuum 400 on the one hand and the Continuum 600 and 1200 on the other hand.

FTX Unix

Stratus 400 Desktop
Continuum suitcase © Stratus 1996

Stratus Continuum 400 were marketed with Stratus-modified HP-UX Unix 11.00 as main choice but also supported Stratus FTX Unix. FTX was System V Unix from Stratus and only sold on an exceptional basis.

FTX (Fault Tolerant Unix) was a System V Unix operating system from Stratus designed for high availability and reliability with fault-tolerance mechanisms. It was developed by Stratus for its own fault-tolerant computer systems.

There also was a cancelled effort to port the Stratus VOS operating system to the 400s. Continuum 400 servers running the Stratus-modified HP-UX 11.00 were fully binary compatible with stock HP-UX — programs compiled for normal HP-UX ran without changes on Continuum 400.

VOS

Stratus Continuum 600 and 1200 were sold primarily with Stratus VOS for transaction processing, with releases 13.0 (1995) to 14.7.2 (2005) on PA-RISC hardware. Also offered on the 600s and 1200s on exceptional basis was Stratus FTX, hardware support was limited though.

VOS was developed by Stratus as transaction-oriented operating system for its fault-tolerant servers. Stratus added a Unix implementation (System V) called Unix System Facilities (USF) to VOS and later added POSIX compliance as well.

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Documentation

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