OpenVMS
The Virtual Memory System (VMS ) is an operating system of the computer manufacturer Digital Equipment Corporation ( DEC) for its Virtual Address eXtension ( VAX ) machines. It was the time of the first publication of an extremely advanced 32 -bit operating system that was multi-user and multi-tasking. It was also one of the first operating systems with virtual memory management, which also justified the naming. Today, it is under the name OpenVMS available in 64 - bit versions.
History
1977 Version 1.0 was released, from the beginning was with DECnet already a powerful point-to -point connection between computers available. In version 4 ( 1983 /84) the first VAXcluster been configured, had a common system disk. At the same DECnet Phase IV was released with full Ethernet support. From version 5 it was with graphical user interfaces deal ( DECwindows - OSF / Motif - compatible). The most recently developed versions 6.x of 1994 had already developed as a support for the VAX successor 64 -bit Alpha processor architecture (this variant was called AXP ), as well as modern data processing with XML and LDAP. Even today, many of the PDP-11, VAX and AlphaServer for large companies, such as Deutsche Börse, EADS or FIAT in use.
The DEC was acquired by Compaq in 1998, which in turn was acquired by Hewlett -Packard in 2002. 1998 bought Robert Boers, one of the former DEC Manager, the " European Migration and Porting DEC Center". It first arose, the company " Software Resources International," today Stromasys. The company developed emulators for old DEC server. The technique OpenVMS can be maintained as an operating system without up -grade.
There is a still active community around now called OpenVMS system. In addition to VAX computers, it also runs on 64 -bit Alpha machines and on Intel IA- 64 systems.
OpenVMS is available in version 8.4, mixed clusters of VAX, Alpha and Itanium II systems were demonstrated. On OpenVMS running in the mobile sector SMS solutions, and exchange systems in the banking sector operated under OpenVMS.
Even before the acquisition by Compaq, Digital had against the U.S. Department of Defense obligated to support VMS for another 20 years. So far it is not clear that HP wants to withdraw from this obligation or can, or that the Department of Defense no longer insists on the fulfillment of this obligation. Plays an important role in this context, certainly the fact that OpenVMS is considered as an operating system that is relatively safe from external attacks.
For non-commercial use licenses for OpenVMS and the main programs are provided as part of the OpenVMS Hobbyist Program (Requires membership in the HP User Association Connect). Does not one of the required hardware for OpenVMS, thanks SIMH a VAX computer can be simulated in software. Also for the AXP architecture, there are free emulators, for example, the staff of Alpha emulator International.
HP announced in June 2013, not a port of VMS on the own server series HP Integrity i4, based on the Itanium 9500 perform. Previous systems are to be sold in 2015 and get 2020 support. This is considered as the end of OpenVMS.
Features
Sometimes OpenVMS is falsely attributed to the Unix-like systems. But OpenVMS has more in common than with Unix with Windows NT. Different concepts that are used today in every current Windows system, originally from VMS.
VMS differs neither in command line arguments or file names in the file system Files -11 between upper and lower case; However, you can since OpenVMS V7.3 -1 a filesystem case sensitive set.
In contrast to Unix disks are not included as a global directory below the root directory, instead there - roughly similar to that of MS -DOS and Microsoft Windows - drive names. The names of devices are part of the hardware used dependent (eg $ 1 $ DGA4711 ), and some can be freely chosen (eg DSA815, a shadowing with a freely selectable number 815).
File names consist of name, file type, and version number (eg name.type, 1), NAME and TYPE are both chains of up to 39 alphanumeric characters. Modified files are saved as a new version, resulting in a incremented version number after a semicolon in the file name is different ( name.type; 1 → name.type; 2). Known of ISO 9660 The older version is not deleted from the system, this the user can do with the DELETE or PURGE commands as needed. The maximum version number is 32767. These is reached, no new version of the file can be created more. A clean up and rename is of course possible.
Be directory name with a ". " Separately and can be inserted in "[] " or "< > " are made to the file name preceded behind a possible drive letters. A subdirectory entry is of type and has an intact file system is always the version number "DIR. " ", 1". As identifiers up to 39 alphanumeric characters can be used.
A full file name is: KNOT :: device: [ Verzeichnis.Unterverzeichnis. ... ] Filename.type, version, where NODE the computer name on the network and device (up to 255 alphanumeric characters) of the physical location ( disk, tape, ...) call.
High availability techniques such as clustering have been implemented early in VMS, still run numerous applications where you need high availability, under this operating system.
As a scripting language, the DIGITAL Command Language (DCL ) is available. Commands are given by convention uppercase, such as SHOW ( information about date, logged in users, free disk space ), RECALL, DIR and HELP.
The developers of VMS took concepts of the PDP systems RSTS / E, RT -11 and RSX- 11, which were widespread in the 1970s in American universities and research institutions worldwide.
As a graphical interface was version 5 by default DECwindows offered. It is an anabolic to CDE window system. X11 and CDE itself can be used as an alternative to DECwindows on OpenVMS.
FreeVMS
A group of programmers working to develop an open source VMS system called FreeVMS, which will also be available on other hardware platforms as DEC Alpha and IA -64. The development is still in a very early stage. Served as a basis up to version 0.3.15, a modified monolithic Linux kernel. The version 0.4 uses a L4/X2-Mikrokernel.