Eumel
Encyclopedia
Eumel is an operating system
which began as a run-time environment
for the ELAN programming language. It was created in 1979 by Jochen Liedtke
at the
University of Bielefeld
. Eumel initially ran on the 8-bit Z80 processor, and was later ported to many different architectures
.
Eumel is based on a virtual machine using a bitcode and achieves remarkable performance and functionality.
Z80-based Eumel systems provide full multi-user multi-tasking operation with virtual memory management and complete isolation of one process against all others.
These systems usually execute Elan programs faster than equivalent programs written in languages such as Basic, Pascal, or Cobol and compiled into Z80 machine language on other operating systems.
One of the main features of Eumel is that it is persistent
, using a fixpoint/restart logic.
This means that if the power fails you only lose a couple of minutes of work: upon restart you continue working from the previous fixpoint with all program state fully intact. This is also known as orthogonal persistence.
Eumel was followed by L3
and later L4
.
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
which began as a run-time environment
Run-time system
A run-time system is a software component designed to support the execution of computer programs written in some computer language...
for the ELAN programming language. It was created in 1979 by Jochen Liedtke
Jochen Liedtke
Jochen Liedtke was a German computer scientist, noted for his work on microkernels, especially the creation of the L4 microkernel family....
at the
University of Bielefeld
Bielefeld
Bielefeld is an independent city in the Ostwestfalen-Lippe Region in the north-east of North Rhine-Westphalia, Germany. With a population of 323,000, it is also the most populous city in the Regierungsbezirk Detmold...
. Eumel initially ran on the 8-bit Z80 processor, and was later ported to many different architectures
Computer architecture
In computer science and engineering, computer architecture is the practical art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals and the formal modelling of those systems....
.
Eumel is based on a virtual machine using a bitcode and achieves remarkable performance and functionality.
Z80-based Eumel systems provide full multi-user multi-tasking operation with virtual memory management and complete isolation of one process against all others.
These systems usually execute Elan programs faster than equivalent programs written in languages such as Basic, Pascal, or Cobol and compiled into Z80 machine language on other operating systems.
One of the main features of Eumel is that it is persistent
Persistence (computer science)
Persistence in computer science refers to the characteristic of state that outlives the process that created it. Without this capability, state would only exist in RAM, and would be lost when this RAM loses power, such as a computer shutdown....
, using a fixpoint/restart logic.
This means that if the power fails you only lose a couple of minutes of work: upon restart you continue working from the previous fixpoint with all program state fully intact. This is also known as orthogonal persistence.
Eumel was followed by L3
L3 microkernel
L3 is a microkernel running on Intel's x86 computers. L3 is designed to be "very lean and features fast, message-based, synchronous IPC, simple-to-use external paging mechanisms and a security mechanism based on secure domains ." It is the predecessor of L4, another microkernel with similar design...
and later L4
L4 microkernel family
L4 is a family of second-generation microkernels, generally used to implement Unix-like operating systems, but also used in a variety of other systems.L4 was a response to the poor performance of earlier microkernel-base operating systems...
.