HP-RT Real-time on PA-RISC

HP-RT
HP-RT
© Hewlett Packard 1997

HP-RT was a real-time operating system from HP for its HP 9000 740 VME instrumentation computers, released from 1993 to 1997 in six versions from 1.0 to 3.0. It was sold as part of the HP-RT Developer’s Kit that included the 743rt and high performance 744rt VME computers.

HP-RT is derived from the real-time operating system LynxOS and was built as hard real-time operating system with native POSIX API and Unix features like protected address spaces, multiprocessing, and standard GUI. Real-time scheduling is part of the kernel with response times under 200 µs, later improved to sub-100 µs for uses such as hospital system tied to a heart monitor, or a missile tracking system.

For programming, HP-RT supported dynamic shared libraries, ANSI C, Softbench (5.2), FORTRAN, ADA, C++ and PA-RISC assembly. From HP-RT 3.0, GUI-based debugging environment (DDErt) and Event Logging library (ELOG) were included. POSIX 1003.1, 1003.1b and POSIX 1003.4a draft 4 were supported.

On the software side, HP-RT supported fast file system, X and Motif clients, X11 SERVERrt, STREAMSrt (SVR 3.2), NFS, and others.

HP-UX RT
HP-RT development © HP Journal

Software development required the HP-RT Development Environment, 740rt VME machines, like the 742rt, but also a dedicated HP 9000 700 host machine with HP-UX for compiling and linking. The software was then downloaded to the rt VME system.

HP 74x VME products were discontinued in 2002 as customers have migrated to new solutions and platforms more rapidly than anticipated with end of support between 2003 and 2007. This EOL included HP-RT as there were no follow-on HP PA-RISC products.

Systems support

HP-RT supported HP 9000 740 Series VME computers with rt suffix that were almost identical to their non-rt products.

System Processor Speed HP-RT versions
HP 9000 742rt PA-7100 50 MHz HP-RT 1.0 to 3.0
HP 9000 743rt PA-7100LC 64 MHz HP-RT 2.0 to 3.0
V743rt Agilent PA-7100LC 100 MHz HP-RT 2.1 to 3.0
HP 9000 744rt PA-7300LC 132-165 MHz HP-RT 3.0

Hardware support

HP 9000 742rt
HP 742 © HP Journal

HP-RT supported most of the on-board hardware and only few expansion boards and devices. Some of the hardware and I/O was first supported in the last HP-RT version 3.01.

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Releases

There were six released versions of HP-RT from 1.0 to 3.01 plus several minor patch releases like 2.11 that were not shipped to all customers. A pause in major releases between 2.0 (1994) and 3.0 (1997) resulted from support needed to be developed for HP-UX 9 and HP-UX 10 in the HP-RT developers kit.

Release Year Additions
HP-RT 3.01 October 1997 744rt/165L, Visualize EG, FWD SCSI
HP-RT 3.0 January 1997 744rt/132L
HP-RT 2.2 June 1996 HCRX graphics, HP-UX 10.10 compatibility
HP-RT 2.1 October 1995 V743rt VXI, 743rt, PCMCIA
HP-RT 2.0 August 1994 743rt
HP-RT 1.1 July 1993 Performance
HP-RT 1.0 January 1993 742rt
HP-RT Kernel
HP-RT kernel © HP Journal

From inception, HP-RT was compliant with POSIX 1003.1 (operating system programming interfaces) and POSIX 1003.4 and 4a drafts (real time extensions and threads).

HP-RT is split into two parts: The HP-RT kernel with low-level I/O drivers, a 10ms interrupt clock, access to hardware timers (1µs) and standard OS functions such as scheduling, multitasking, memory management, IPC and kernel services. The second part: HP-RT services contain optional higher-level functions such as NFS, TCP/IP, debuggers.

The HP-RT developer’s kit (B5486AA) cost $9,995 at time of release for single license to use and a software/documentation bundle. HP-RT development and releases were a bit in flux throughout the short timespan of commercial support and HP-RT ended soon after 744rt workstations and HP-UX 10.20 EOL.

HP-RT 3.0

HP-RT 3.00 was released as the last major version in January 1997. It added support for the PA-7300LC-based VME workstations 744rt/132L (no graphics yet) and updated the HP-RT operating system core significantly.

HP-RT 3.01 was the last version of HP-RT from October 1997 and added mostly hardware support, including for the 744rt/165L

HP-RT 2.0

The second HP-RT major release 2.0 was introduced in August 1994 and added support for HP 9000 743rt based on PA-7100LC processors. Besides hardware, HP-RT 2.0 added some features:

HP-RT 2.1 was released in October 1995 and added more features and support for the (Agilent) V743rt VXI workstations with 32-bit PA-7100LC processors. The 743rt (and 742rt?) workstations were still supported.

HP-RT 2.2 was released in June 1996 with several functional enhancements:

There might have been a HP-RT 2.21 that already supported 744rt/132L, the GSC second slot expansion kit and external SCSI drives and DDS tapes.

HP-RT 1.0

The first HP-RT version 1.0 was released in January 1993, it supported the 742rt VME-based workstation on PA-7100 processors.

Features of HP-RT 1.0 were:

HP-RT 1.1 was released in July 1993 and extended some HP-RT features:

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Documentation

Almost all information on HP-RT has been gone from the internet for years.

Product features

Websites

Manuals

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