MUNIX

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MUNIX
developer PCS computer systems
License (s) Proprietary
ancestry UNIX
↳ MUNIX
Architecture (s) PCS QU68000, Digital PDP / LSI-11
Others Development stopped

Munix was a commercial UNIX - Operating system of the German company PCS Computer Systems (PCS) and is designed for use in professional CAD workstations Cadmus developed. Development began in the early 1980s starting with UNIX version 7. The first versions also had a screen-oriented editor, bad block handling , Fortran 77 , Pascal , C and a screen-oriented debugger.

particularities

In addition to the standard Unix functionalities, Munix has various extensions. The Newcastle Connection (“Unixes of the world, unite!”) Was a chargeable extension with which the file namespaces of several computers could be combined under one super root. Diskless nodes were also implemented on this basis.

The super root

Below the standard root directory “/” (root directory, root) of a Unix computer, there is usually the directory entry “/ ..”, which, however, refers to the same inode as “/” itself. Under Munix it is possible to replace this directory entry with a so-called super root. This super root is a real directory in which further directories can be created and on which the entire file tree of another Munix computer can be mounted via the network. Are there e.g. If, for example, two computers "pcs2a" and "pcs2b" are connected in a network, you can access the root directory of the computer pcs2b from the computer pcs2a via the path "/../pcs2b". These are automatically attached when the system is started if the computers were previously connected with the shell scripts " connectnodes " and " uunite ". The device files in the / dev folder that are used when mounting are a variety of symbolic links that refer to the Ethernet ID of the Munix computer to be mounted. The block devices are also made available via the network so that, for example, the / dev / is0 computer on the “pcs2b” computer can access the magnetic tape drive / dev / is0 via the path /../pcs2b/dev/is0 completely transparently (compare Network Block Device under Linux ).

The concept of the diskless node

The computers on which Munix were used (Cadmus workstations) have a so-called ICC board (Intelligent Communication Controller), which is not only able to load from hard drives and magnetic tapes , but also via networks. The other Munix computers in the same network segment with their own hard disks serve as servers that provide the diskless nodes with their own directory tree. The files, which can be write-protected, are linked to the server via the super root. The ICC board of the diskless node first determines the Ethernet ID of the server via a broadcast on the network and then starts with files loaded via the network: 

 <- L icckernel        (Laden des ICC-Kernels)
 <- L /../pcs2b/unix   (Laden des Unix-Betriebssystems)
 <- I -s               (Startbefehl an den ICC zum Starten des Betriebssystems)

It is <-the system prompt, and the rest each line of self-running boot process, but can also enter by hand.

See also

Individual evidence

  1. ↑ Source license bears fruit: Munix is ​​Unix from Munich. In: computerwoche. January 14, 1983, archived from the original on March 7, 2016 ; accessed on October 18, 2019 .
  2. ↑ "The Newcastle Connection" or "UNIXes of the World Unite!" (PDF)