Web site: (not active)
Origin: USA
Category: Server
Desktop environment: CLI
Architecture: VAX-11
Based on: UNIX compatible
Wikipedia: LOCUS
Media: Install
The last version | Released: 1983

LOCUS – a UNIX-like distributed operating system developed at UCLA (University of California, Los Angeles, USA) between 1980 and 1983.

LOCUS is a distributed operating system which supports transparent access to data through a network wide filesystem, permits automatic replication of storaget supports transparent distributed process execution, supplies a number of high reliability functions such as nested transactions, and is upward compatible with Unix. Partitioned operation of subnetl and their dynamic merge is also supported.
The system has been operational for about two years at UCLA and extensive experience in its use has been obtained.

LOCUS is a Unix compatible, distributed operating system in operational use at UCLA on a set of 17 Vax/750’s connected by a standard Ethernets. The system supports a very high degree of network transparency, i.e. it makes the network of machines appear to users and programs as a single computer;
machine boundaries are completely hidden during normal operation. Both files and programs can be moved dynamically with no effect on naming or correct operation. Remote resources are accessed in the same manner as local ones. Processes can be created locally and remotely in the same manner, and process interaction is the same, independent of location. Many of these functions operate transparently even across heterogeneous cpus.

LOCUS also provides a number of high reliability facilities, including flexible and automatic replication of storage at a file level, a full implementation of nested transactions[MEUL 83], and a substantially more robust data storage facility than conventional Unix systems. All of the functions reported here have been implemented, and most are in routine use.

An important part of the LOCUS research concerns recovery from failures of parts of the system, including partition of a LOCUS system into separated but functioning subnetworks.


No download is available.


DEMOS on WIndows

Web site: (not active)
Origin: Russia (Soviet Union)
Category: Server
Desktop environment: CLI
Architecture: Motorola 68020, PDP-11, CM 1700, XT Clones
Based on: BSD
Wikipedia: DEMOS
Media: Install
The last version | Released: 3.0 ? | May 1983 ?

DEMOS / Демос (Dialogovaya Edinaya Mobilnaya Operatsionnaya Sistema / Диалоговая Единая Мобильная Операционная Система) – a Soviet version of Unix that included portions of AT&T Unix, portions from BSD, and some parts translated into Russian, and other utilities written in Russian.

The system development been started by Kurchatov Institute of Atomic Energy in 1982, and later development was doing with cooperation of DEMOS Co-operative.

It was developed for:
– SM-4 (a PDP-11/40 clone)
– SM-1600

It was ported to:
– Elektronika-1082
– clones of VAX-11(SM-1700)
– Elektronika-85 (a clone of DEC Professional)
– Motorola 68020-based microcomputers

The project been closed in 1991.

The screenshot source:; author: Neozeed; license: GNU Free Documentation License 1.2.