No RISC No Fun
OpenPA is an independent technical resource on HP 9000 and PA-RISC computers and operating systems. Online since 1999 with more than 140 articles on PA-RISC, a technical computer architecture developed by HP in the 1980s and 1990s:
- Hardware: OpenPA covers HP PA-RISC architecture and processors from early RISC experiments in the 1980s to 64-bit multicore CPUs in custom HP RISC designs.
- Computers: HP released a wide array of PA-RISC computers, from servers, 3D workstations to mainframes in the HP 9000, Visualize and Integrity ranges.
- Operating: Unix was the operating system of choice on PA-RISC, with ports of HP-UX, Mach, BSD, Linux and many R&D and open source projects.
Information on OpenPA is based on PA-RISC technical references, handbooks and architecture documents, correlated with disappearing archives. OpenPA is independent of and does not represent HP in any way. Read our news, RSS and our book.
Also on OpenPA: RISC Laptop Archive and VLIW CPUs, computing history of the 1990s.
Emulators for PC and Mac on HP-UX

With HP-UX software emulators for PC and Macintosh systems, HP 9000 PA-RISC workstations could run 1990s-vintage DOS, Windows and Apple Mac OS and applications. While the main use of HP-UX workstations usually was design and engineering, the use of emulators allowed these technical systems and their users to connect to wider office and productivity applications in the office to use mail, office and shared environments.
There were at least four computer emulators for HP-UX, all released in the 1990s era of Unix and RISC. Apple MAE and Andataco Liken provided an 680x0-based Macintosh (classic) environment, while Sun Wabi and Insignia SoftWindows emulated x86 PCs for DOS and Windows. All of these emulators were commercial products developed and sold by those vendors with different releases and platforms in the 90s.
- MAE (Apple): The Macintosh Application Environment, sold by Apple in the 1990s, supported HP-UX and PA-RISC in MAE 2.0 and 3.0. MAE emulated a 68040LC Macintosh with System 7.1 and System 7.5 on HP-UX 9 and 10.
- Liken (Andataco): Liken 2.0 was Macintosh emulator for Unix systems released in 1994 with HP-UX support. Hardware support and performance was limited and only Macintosh System 6 was emulated. Display was monochrome-only and a HP 9000 712 emulated Mac OS with the speed of a Mac IIsi.
- SoftWindows (Insignia): The suite of SoftPC and SoftWindows had support for Unix and especially HP-UX in multiple versions, at least SoftWindows 1.0, 2.0 and 4.0, released between 1994 and 1997. Emulated were Intel i486 and Pentium CPUs for DOS, Windows 3.1, 3.11 and later Windows 95.
- Wabi (Sun): HP licensed Wabi, the PC emulator for DOS and Windows, from Sun for multiple versions on HP-UX between 1994 and 1997. The HP Wabi products 1.1, 2.0, 2.1 and 2.2 supported Windows 3.1 and 3.11 with a select set of compatible Windows applications with i486-like performance.




HP Unix workstation endgame in the 2000s
The era of HP Unix workstations came to a close in the early 2000s. After a long line of PA-RISC HP 9000 700 and HP Visualize workstations for HP-UX in the 1990s, HP slowly transitioned its RISC and Unix offering towards server at the turn of the century. In the early 2000s, HP released a last batch of technical Unix workstations based on PA-RISC
Workstation | Architecture | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 |
---|---|---|---|---|---|---|---|
B-Class | PA-RISC 2.0 | B2000 B2600 |
|||||
C-Class | PA-RISC 2.0 | C3600 C3700 |
C8000 | ||||
J-Class | PA-RISC 2.0 | J5000 J5700 |
J6000 J6700 |
||||
i-Class | Itanium | i2000 | |||||
zx | Itanium 2 | zx2000 zx6000 |
At the end of the PA-RISC heydays, HP released the final 64-bit PA-RISC workstations: in 2000 with Visualize B2000 and B2600 and J5000 and J7000 workstations, based on PA-8500 and PA-8600 processors, followed in 2001 by C3600 to C3750 and J6000 to J6750 workstations with PA-8700 processors in an HP Astro design.

The end of PA-RISC was already near, however. HP had been working on VLIW as a RISC successor since the late 1980s. Later joined by Intel, this led to a VLIW processor design called EPIC by HP and Itanium by Intel. HP planned to use Itanium widely for its Unix business in the mid-1990s, but CPUs and computers were shipped only in 2001.

The first, almost unknown today Itanium workstation was the HP i2000, based on the first Merced IA64 processor and an Intel 82460GX reference design. The i2000 was slower than contemporary PA-RISC workstations and generally not very popular with clients (and HP), but it ran HP-UX, OpenVMS, Windows XP and 2000 and Linux plus FreeBSD.

The prototype i2000 (MVP
) was followed by the second line of HP Itanium workstations, zx2000 and zx6000 with newer HP Itanium 2 processors and closely based on HP Integrity rx server architecture with HP zx1 Itanium chipsets.
HP discontinued Itanium workstations soon after releasing the zx workstations, with Unix mostly confined to servers.

The last PA-RISC workstation followed two years after their zx-Class Itanium VLIW replacements were brought to market: HP C8000 were the pinnacle of PA-RISC and the ultimate HP-UX Unix workstation, released in 2004. Geared towards customers that needed specific PA-RISC and HP-UX applications for a few more years, they never had real benchmark figures published, but C8000 with dual-core PA-8900 Mako processors were rather fast.
All of these workstations were designed for the latest version of HP Unix, HP-UX 11i v1 for PA-RISC and 11i v2 for Itanium, to be used to technical computing such as CAD, CAM and 3D. There was initial Linux support for the PA-RISC workstations, and Windows and Linux options for Itanium workstations, helped by HP.
The confused versioning of HP-UX 11i (11.11)
HP-UX 11i v1 is HP’s Unix operating system for its 64-bit PA-RISC servers and workstations and some 32-bit PA-RISC computers, released from 2000 to 2006. Previous HP-UX 11.00 was the first 64-bit HP Unix. HP released HP-UX 11i originally as HP-UX 11.11, changed later to 11i and even later to 11i v1 to differentiate server and Itanium products (11i v2, v3 ...).
With HP-UX 11i v1 HP introduced operating environments (OEs) that were different for workstations and servers and their specific use cases:
- Technical Computing Operating Environment (TCOE) for workstations
- Minimal Technical Operating Environment (MTOE) for workstations
- Mission Critical Operating Environment (MCOE) for servers
- Enterprise Operating Environment (EOE) for servers




To complicate matters even further, not all HP-UX 11i v1 versions supported the same set of HP PA-RISC workstations and servers – support fluctuated strongly based on cyclical HP-UX releases between December 2000 and December 2006.
Class | Computers | Versions | Environments |
---|---|---|---|
HP 700 | 712, 715/64, 80, 100, 725/100 | 12/00-12/04 | TCOE, MTOE |
HP 700 | 743i, 744, 745, 748i, 748 | 12/01-12/04 | TCOE, MTOE |
Portables | RDI PrecisionBook, SAIC Galaxy 1100 | 12/00-12/04 | TCOE, MTOE |
HP A-Class | A180, A180C, A400, A500 | 12/00-12/06 | OE, EOE, MCOE |
HP B-Class | B132L, B160L, B132L+,
B2000 B180L+, B1000 B2600 |
12/00-12/04 12/00-09/05 06/01-12/06 |
TCOE, MTOE |
HP C-Class |
C100, C110, C132L, C160L,
C160, C180 C200, C240, C360, C3000 C3600 C3650, C3700 C3750 C8000 |
12/00-12/04 12/00-09/05 12/00-12/06 12/01-12/06 12/02-12/06 12/04-12/06 |
TCOE, MTOE |
HP D-Class | D210, D310 | 12/00-12/04 | OE, EOE, MCOE |
HP D-Class | D220, D230, D250, D270, D280 D320, D330, D350, D370, D380, D390 |
12/00-12/06 | OE, EOE, MCOE |
HP J-Class |
J200, J210, J280, J282, J2240 J5000, J7000 J5600, J7600, J6000 J6700 J6750 |
12/00-12/04 12/00-09/05 12/00-12/06 12/01-12/06 12/02-12/06 |
TCOE, MTOE |
HP K-Class | K100, K200, K210, K400, K410 | 12/00-12/04 | OE, EOE, MCOE |
HP K-Class | K220, K250, K260, K360, K370, K380 K420, K450, K460, K570, K580 |
12/00-12/06 | OE, EOE, MCOE |
HP L-Class | L1000, L2000 | 12/00-12/06 | OE, EOE, MCOE |
HP L-Class | L1500, L3000 | 06/01-12/06 | OE, EOE, MCOE |
HP N-Class | N4000, N4000 | 12/00-12/06 | OE, EOE, MCOE |
HP R-Class | R380, R390 | 12/00-12/06 | OE, EOE, MCOE |
HP T-Class | T500, T520 | 12/00-12/04 | OE, EOE, MCOE |
HP T-Class | T600 | 12/00-12/06 | OE, EOE, MCOE |
HP V-Class | V2200, V2250, V2500, V2600 | 12/00-12/06 | OE, EOE, MCOE |
HP Superdome | PA-RISC models | 12/00-12/06 | OE, EOE, MCOE |
HP rp | rp2400, rp2450,
rp5400, rp5450 rp5430, rp5470, rp7400, rp8400 |
12/01-12/06 | OE, EOE, MCOE |
HP rp | rp2430, rp2470, rp7410 | 03/02-12/06 | OE, EOE, MCOE |
HP rp | rp7405 | 12/02-12/06 | OE, EOE, MCOE |
HP rp |
rp3410, rp3440,
rp4410, rp4440 rp7420, rp8420 |
12/03-12/06 | OE, EOE, MCOE |
HP rp | rp7420, rp8420 | 12/04-12/06 | OE, EOE, MCOE |
HP rp | rp2405 | 12/04-12/06 | OE, EOE, MCOE |
Not supported | 705, 710,
715,
720, 730, 750,
735, 755 E-Class, HP 9000 800 Nova |
12/00 |
RISC Laptop: Toshiba SPARC LT AS1000

Another entry in the RISC Laptops series on 1990s Unix laptops with RISC processors: Toshiba SPARC LT laptops based on Sun SPARC architecture for Unix.
Toshiba SPARC LT AS1000 laptops were released in 1990 and were one of the first Unix laptops developed with still early RISC technology in the 1980s.
SPARC LT were close to Sun SPARCstations (1+ or 2) but needed modified SunOS for the custom Toshiba system design. After the original SPARC-based L10 and E10 versions, Toshiba added SuperSPARC C60, C70 and C80 models a few years later with newer CPUs, but it seems in only a very limited fashion.
Contemporary reviews in the early 1990s were unsure on the need for mobile engineering computers:
Some experts have questioned the need for laptop workstations because the scientists and engineers who use them are often networked into high-powered mainframes. As a result, the advantages of portability are not as clear-cut as they would be for personal computer users.
Toshiba SPARC LT laptops were sold primarily in Japan, priced at ¥1,980,000, but were marketed pretty intensively in the US and Europe.
New OpenPA Book Edition 3.0
A new edition of the OpenPA PA-RISC Book has been released. Available as PDF, the Book of PA-RISC is in its fourteenth release, now in Edition 3.0 with more than 500 pages of PA-RISC information! Much new PA-RISC content has been added and many existing chapters revised and extended.

Some of the major changes since the last release:
- PA-RISC Architecture and Precision
- HP Visualize Intel-based Workstations
- HP Visualize 3D accelerators
- HP Visualize for Intel graphics
- Unix games for HP-UX
- ATI and nVIDIA graphics for PA-RISC and Itanium
- Research operating systems for PA-RISC
- More HP-RT content
- PA-RISC performance and SPECtable
- SAIC Talon portable computer
- QEMU PA-RISC emulation
Download the OpenPA Book of PA-RISC
(PDF, 2.0 MB, 541 pages, 2025, V3.0)
Includes all content from the OpenPA Winter 2025 online version.
Emulating PA-RISC computers with QEMU
QEMU is an open source computer emulation and virtualization software for many different computer systems. It includes support for many RISC architectures besides x86, with PA-RISC emulation since 2018. Current QEMU version is 9.2.0.
QEMU emulates a complete computer in software without the need for specific virtualization hardware. With QEMU, a full HP Visualize B160L and C3700 workstation can be emulated to run PA-RISC operating systems. QEMU emulates PDC, I/O routines and hardware so the emulation appears as a complete system to the operating system.
Most PA-RISC operating systems should work under QEMU emulation of HP B160L and C3700 PA-RISC workstations. OpenPA tested a few of those systems in late 2024.

- HP-UX: Made HP-UX 10.20 and 11.00 work with CDE
no luck with 9.07 and 11.11 - Linux on PA-RISC supposedly works, did not test
- NetBSD/hppa supposedly works, did not test
- OpenBSD/hppa 7.6 did install from CD but crashes on restart of the installed system
- NeXTSTEP 3.3 boots but the installer crashes
possibly missing QEMU drivers - MkLinux supposedly works partially
There are some configuration and command hints for using QEMU on PA-RISC.
RISC of the 90s: Intel iWarp VLIW Processors
A very forgotten VLIW architecture of the late 1980s:
Intel iWarp is a combined VLIW and RISC computer architecture that coupled a 32-bit CPU core with long instructions and powerful communication support
to enable meshed computers for powerful parallel computing with >20 GFLOPS.

Intel iWarp was jointly developed between Intel and Carnegie Mellon University, supported by DARPA (DoD) in the late 1980s.
It was based on the earlier CMU Warp, a programmable systolic array
for meshed computing and communications.

Computers with up to 1,024 CPUs could be closely coupled for signal processing with potential military uses.
Intel shipped first iWarp computers with 64 nodes to CMU in 1991 and sold iWarp computers until iWarp was integrsted into the Supercomputing Systems Division at Intel.
Chips were military-grade, as the i386 process used for manufacturing was approved by NASA and pretty rad-hard.


There were multiple iWarp configurations available by Intel:
- Quad Cell Board (QCB) with four iWarp processors
- Card Cage Assembly (CCA) with four QCBs = 64 iWarp processors (8x8 torus), a typical iWarp system
- System Cabinet with four CCAs = 256 nodes
- Multi-Cabinet with four System Cabinets = 1024 nodes
- Variations of these in other form-factors and interfaces
Intel iWarp computers used a narrow set of software and development components: RTS (Run Time System) kernel, Pathlib for systolic communication, C and assembler, Fortran 77, Apply.
RISC of the 90s: Sun MAJC VLIW Processors

Another forgotten VLIW processor of the 1990s:
Sun MAJC is a VLIW architecture developed by Sun for media and signal processing.
Sun produced one MAJC processor in 1999, MAJC-5200, a high performance general purpose microprocessor
for multimedia and Java computing.

Reviewers of the late 1990s were ecstatic:
Doubts that VLIW has succeeded RISC as the most important influence on new microprocessor architectures vanished
at the time when Sun pulled the latest example out of its hat: MAJC (pronounced magic).
MAJC is a scalable architecture that exploited multiple forms of parallelism, a hot topic of 1990s microarchitecture.
MAJC was multiprocessing capable with vertical micro-threading
and very long instruction word (VLIW) for multiple instructions per cycle.
The single MAJC-5200 processor had two CPU cores with each four functional units, a central crossbar and was four instructions wide.
Planned for multimedia portal PCs with Java and high-end graphics, Sun MAJC processors wound up in two Sun XVR accelerators in the early 2000s.
Its 6 Gigaflops performance was downright scary
but commercial success eluded the MAJC CPUs.
There was no binary compatiblity to anything and the Java link was tenous.
RISC of the 90s: Philips TriMedia VLIW Processors

New series on forgotten VLIW and RISC Processors of the 1990s with Philips Trimedia VLIW as first article. The series was motivated by the HOT CHIPS conferences with so many unknown CPUs of the 90s.
Philips TriMedia is a range of 32-bit VLIW processors for media processing released during the 1990s: TM-1000 was the first CPU, released in 1996, followed by TM-1100 in 1998 and TM-1300 (PNX1300) in 1999.
TriMedia was based on original VLIW work at Philips research in the 1980s for general computing. Actual production TriMedia VLIW processors in the 1990s were more specialized for media computations. They could issue five instructions per clock for any of their 27 (!) functional units at clock speeds between 100 and 166 MHz.
They were mostly used in audio, video and photo devices as media co-processors for video conferencing, web and CCD cameras, video editing, HDTVs and video mail (?!).
More VLIW and RISC processors will be detailed in this series on the 1990s.
RISC Laptop: IBM WorkPad z50

Another entry in the RISC Laptops series on 1990s Unix laptops with RISC processors: IBM WorkPad z50.
It looks like a Thinkpad, but it’s not.
The WorkPad z50 is a mobile companion
released by IBM in 1999 with MIPS processor for Windows CE.
Aimed at the fledging handheld PC and PDA market of the late 90s, z50 were almost laptops but still had a RISC processor: NEC VR4121, a 64-bit MIPS processor.
IBM WorkPad z50 was a small system with a 8.2″ DSTN screen, weighing 2.66 lbs in a compact 8.0″ x 10.2″ x 1.0″ case. Operating system and applications were in ROM modules with a focus on personal productivity on embedded Windows CE 2.11. It had pretty positive reviews in the PDA/HPC market of the turn of the century.
SAIC Talon PA-RISC Portable Severe Workstations
SAIC apparently produced another PA-RISC portable computer in the mid-1990s: the SAIC Talon. Compared to the well-known boxy Galaxy 1100, the Talon is even more rugged at almost 50 pounds and integrated a 32-bit HP 9000 712 PA-RISC system design into a military portable case.

SAIC Talon PA-RISC portables were apparently produced as part of the US Navy TAC-4 program, under which HP provided PA-RISC gear to the Navy, supported by SAIC for rugged computers in severe
environments.
The prior SAIC Galaxy was already pretty rugged but the Talon added to this with extensive military requirements for shock, sound, rain, airborne and Fungus: No growth.
Also based on HP 9000 712 workstation design, SAIC added PCMCIA for extensions and an EISA bus slot for interfaces, to which a VME adapter could be connected. SAIC Talons are almost unknown today with only very few public information available since then. Talons are mentioned in SAIC websites from 1996 but it remains unclear if and how these computers were actually productized.
Hot Chips Conference: RISC in the 1990s
HOT CHIPS is an IEEE conference on microprocessors and microcomputers, organized yearly since 1989. Almost all cutting edge RISC and computer architectures of the 1990s were presented at HOT CHIPS over the years, PA-RISC information can be found at the conference in HP presentations between 1991 and 1999.

Most historic HOT CHIPS programs and proceedings are available in archives, after having been hosted until the 2010s at official HOT CHIPS. These older HOT CHIPS presentations offer an interesting glimpse into the wildly diverse CPU landscape of the 1990s. Some notable PA-RISC presentations at HOT CHIPS:
- PA-RISC Processor for Snakes Workstation, Hewlett Packard, HOT CHIPS 3 (1991)
- A 200 MFLOP HP PA-RISC Processor, Hewlett Packard, HOT CHIPS 4 (1992)
- Multiprocessor Features in a PA-RISC Processor Interface Chip, Hewlett Packard, 1992
- Hummingbird: A Low-Cost Superscalar PA-RISC Processor, Hewlett Packard, HOT CHIPS 5
- System Design Verification of the HP735 VLSI, Hewlett Packard, HOT CHIPS 5 (1993)
- A Single-Chip Workstation Graphics System, Hewlett Packard, HOT CHIPS 5 (1993)
- Multimedia Enhancements for PA-RISC Processors, Hewlett Packard, HOT CHIPS 6 (1994)
- Memory Performance Features of the 64-bit PA-8000, Hewlett Packard, HOT CHIPS 7, ’97
- A 150MHz Superscalar RISC Processor with Pseudo Vector Processing Feature, Hitachi, HOT CHIPS 7 (1995)
- The HP PA-8000 RISC CPU: A High Performance Out-of-Order Processor, Hewlett-Packard, HOT CHIPS 8 (1996)
- Effectiveness of the MAX-2 Multimedia Extensions for PA-RISC 2.0 Processors, Hewlett-Packard, HOT CHIPS 9 (1997)
- Techniques for Mitigating Memory Latency in the PA-8500 Processor, HOT CHIPS 10 ’98
The Internet never forgets – OpenPA and fleeting PA-RISC information since 1999.
Download the OpenPA Book of PA-RISC
(PDF, 2.0 MB, 541 pages, 2025, V3.0)
Includes all content from the OpenPA Winter 2025 online version.
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