PA-RISC Operating Systems
A broad range of operating systems is available for HP’s PA-RISC based workstations and (to a lesser extent) servers. Noteworthy is that all of these systems are either Unix or Unix-like — different designs have both been ported to and developed specifically for these systems. Most of the earlier efforts were distributed only to a small (mostly academic) circle and not available to the general public, the current open-source projects are offered free of charge together with sources to the general public.
This section aims to give an in-depth view on the available PA-RISC operating systems, their requirements and current status.
Commercial
Not many commercial operating systems were offered for PA-RISC computers, the two most prominent include HP-UX and NeXTSTEP. However it must be noted that HP also sells a real-time OS for these systems, called HP-RT.
HP-UX is HP’s own Unix version for PA-RISC computers. Every PA-RISC based computer system produced by HP is or was supported by HP-UX in some version.
» Go to the HP-UX page.
NeXTSTEP was a revolutionary operating system based around a Mach microkernel with an Unix-userland and a very slick GUI. Support for some 32-bit PA-RISC machines was available in Version 3.3, though only a small subset of the HP 9000 hardware was supported.
» Go to the NeXTSTEP page.
Open Source
Several Unix-like open source operating systems were ported over the time to the PA-RISC architecture, including Linux, OpenBSD and NetBSD.
PA-RISC Linux supports different machines from the newer 32 and 64-bit series though proper support is still missing for a lot of systems. Linux does not perform equally well as original HP-UX on PA-RISC systems and hardware support is in contrast still limited.
» Go to the Linux page.
OpenBSD/hppa supports most 32-bit systems and some 64-bit systems which can run in 32-bit mode. Machines running in 64-bit mode are currently not supported and later will supposedly be by an OpenBSD/hppa64 port.
» Go to the OpenBSD page
NetBSD supports several 32-bit machines, support for newer machines was ported over from OpenBSD and is stabilizing. At the moment the NetBSD/hp700 port is in a runnable state and supports some systems and most of the hardware OpenBSD/hppa supports.
» Go to the NetBSD page.
Research Projects
Attempts to port research operating systems to PA-RISC were undertaken at different places over the time, all being BSD/Unix operating systems based mostly on the Mach microkernel (and OSF/1). These ports were mostly development or research projects, and not operating systems releases in the formal sense. Large parts of these ports were developed at the University of Utah and later formed the starting point for PA-RISC ports of other operating systems (OpenBSD, Linux).
These ports include HPBSD, Mach-based Unix/BSD systems (Mach 2/3 with HP-UX, Mach 3 with AT&T Unix, Mach 4 with 4.4BSD Lites), Chorus (similar to Mach), two OSF/1 ports (one with Mach 2/3 from HP and one later one from OSF) and MkLinux (OSF Mach with Linux).
» Go to the Other PA-RISC Operating Systems page