Jørn Jensen, one of the earliest Danish

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 programmers. Examined as a mechanical engineer and had worked with electromechanical construction. In 1958 employed at the Danish Regnecentralen

Regnecentralen

Regnecentralen, or RC for short, was the first Danish computer company, founded on October 12, 1955. Through the 1950s and 60s they designed a series of computers, originally for their own use, and later to be sold commercially. Descendants of these systems sold well into the 1980s...

, and very soon exhibited an extraordinary programming skill. He developed the main parts of the base programs to DASK

DASK

The DASK was the first computer in Denmark. It was commissioned in 1955, designed and constructed by Regnecentralen, and began operation in September 1957. DASK is an acronym for Dansk Algoritmisk Sekvens Kalkulator or Danish Algorithmic Sequence Calculator. Regnecentralen almost didn't allow the...

, the first Danish computer – among others, he designed a collection of monitor programs to supervise the program running schedule on DASK. In tight collaboration with Peter Naur

Peter Naur

Peter Naur is a Danish pioneer in computer science and Turing award winner. His last name is the N in the BNF notation , used in the description of the syntax for most programming languages...

 and others, he developed reliable, well documented compilers to the ALGOL 60

ALGOL

ALGOL is a family of imperative computer programming languages originally developed in the mid 1950s which greatly influenced many other languages and became the de facto way algorithms were described in textbooks and academic works for almost the next 30 years...

 programming language. In this context he invented Jensen's Device

Jensen's Device

Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen, who worked with Peter Naur at Regnecentralen, particularly on the GIER Algol compiler, one of the earliest correct implementations of ALGOL 60....

, an ingenious exploitation of the name parameters to compute numerical series without using procedure parameters – as is necessary in all programming languages, except ALGOL 60

ALGOL

ALGOL is a family of imperative computer programming languages originally developed in the mid 1950s which greatly influenced many other languages and became the de facto way algorithms were described in textbooks and academic works for almost the next 30 years...

, and Simula-67

Simula

Simula is a name for two programming languages, Simula I and Simula 67, developed in the 1960s at the Norwegian Computing Center in Oslo, by Ole-Johan Dahl and Kristen Nygaard...

.

After circa 20 years at Regnecentralen he continued his career as a systems programmer among others in the Brown Boveri company.