Mes début sur Digital Unix

Mes début sur Digital Unix
Digital Unix est l’ancien nom du système d’exploitation des ordinateurs Alpha de la société Digital Equipment Corporation (DEC). C’est un systeme d’exploitation Unix. Ce système a été rebaptisé Tru64 Unix. La société Digital Equipment Corporation a été rachetée par Compaq puis par HP.
First release of Ultrix

The first native VAX UNIX product from DEC was Ultrix-32, based on 4.2BSD with some non-kernel features from System V, and was released late 1984. Ultrix-32 was primarily the brainchild of Armando Stettner. Its purpose was to provide a DEC-supported native Unix for VAX. It also incorporated several modifications and scripts from Usenet/UUCP experience gained while running decvax. Later, Ultrix-32 incorporated support for DECnet and other proprietary DEC protocols such as LAT. It did not support VAXclustering. Given Western Electric/AT&T Unix licensing, DEC (and others) were restricted to selling binary-only licenses. A significant part of the engineering work was in making the systems relatively flexible and configurable despite their binary-only nature.

After Ultrix-32 completed its first phase of customer beta trials, Armando moved to the West Coast to help Steve Bourne start up DEC’s Workstation Systems Engineering organization, an advanced development group focusing on graphics and workstations. From there, he went on to conceive of, write its first charter, and help in the formation of the Open Software Foundation. Armando then worked in a very small cross organizational group from which spawned DEC’s first RISC workstation product, the MIPS-based DECstation 3100.

In the end, DEC provided its Ultrix-branded native Unix operating systems on three platforms : PDP-11 minicomputers (where Ultrix was one of many available operating systems from DEC), VAX-based computers (where Ultrix was one of two primary OS choices) and the DECstation workstations and DECsystem servers (where Ultrix was the only OS choice offered). Note that the DECstation systems used MIPS processors and predate the much later DEC Alpha-based systems.

The V7m product was later renamed to Ultrix-11 to establish the family with Ultrix-32, but as the PDP-11 faded from view Ultrix-32 became known simply as Ultrix. When the MIPS versions of Ultrix was released, the VAX and MIPS versions were referred to as VAX/ULTRIX and RISC/ULTRIX respectively. Much engineering emphasis was placed on supportability and reliable operations including continued work on CPU and device driver support (which was, for the most part, also sent to UC Berkeley), hardware failure support and recovery with enhancement to error message text, documentation, and general work at both the kernel and systems program levels. Later Ultrix-32 incorporated some features from 4.3BSD and included DECnet in addition to the standard TCP/IP, and both the SMTP and DEC’s Mail-11 protocols.

Notably, Ultrix implemented the inter-process communication (IPC) facilities found in System V (named pipes, messages, semaphores, and shared memory). While the converged Unix from the Sun and AT&T alliance (that spawned the Open Software Foundation or OSF), released late 1986, put BSD features into System V, DEC took the best from System V and added it to a BSD base.

Originally, on the VAX workstations, Ultrix-32 had a desktop environment called UWS, Ultrix Workstation Software, which was based on a version of the X Window System. Later, the widespread version 11 of the X Window System (X11) was added, using a look and feel called DECwindows that was devised in order to mimic the look and feel of the UWS system. Eventually DECwindows also provided the Motif look and feel.

Ultrix ran on multiprocessor systems from both the VAX and DECsystem families. The kernel supported symmetric multiprocessing while not being fully multithreaded based upon pre-Ultrix work by Armando Stettner and earlier work by George Goble at Purdue University. As such, there was liberal use of locking and some tasks could only be done by a particular CPUs (e.g. the processing of interrupts). This was not uncommon in other SMP implementations of that time (e.g. SunOS). Sadly, Ultrix was slow to support many then new or emerging Unix system capabilities found on competing Unix systems (e.g. it never supported shared libraries or dynamically linked executables ; delay in implementing bind, 4.3BSD system calls and libraries especially the math libraries ; etc.) and suffered from some problems, most notably file system integrity issues (having never picked up the 4.3BSD filesystem and fixes).